Dr. Jeffrey Goldberg: How to Improve Your Eye Health & Offset Vision Loss

welcome to the huberman Lab podcast

where we discuss science and

science-based tools for everyday life

I'm Andrew huberman and I'm a professor

of neurobiology and Ophthalmology at

Stanford School of Medicine

today my guest is Dr Jeffrey Goldberg Dr

Jeffrey Goldberg is the chair of the

Department of Ophthalmology at Stanford

University School of Medicine he is a

clinician and MD or medical doctor who

sees patients every week as well as a

PhD meaning a laboratory scientist who

directs his own laboratory focused at

understanding the mechanisms and cures

for diseases of the eye Envision such as

glaucoma retinitis Pigmentosa and

macular degeneration indeed Dr Goldberg

is one of the world leaders in

developing methods to cure blindness he

is also intensely knowledgeable about

all things related to Vision so during

today's discussion we indeed cover most

all of visual and Eye Health you will

learn for instance about the benefits as

well as drawbacks of wearing corrective

lenses such as contact lenses or

eyeglasses for reading you will learn

about the benefits and detriments of

sunlight meaning how it can help your

vision in fact how it can help reverse

or prevent my own Opia nearsightedness

as well as the things to be cautious

about with respect to sunlight in terms

of development of cataracts which are

occlusions that prevent Vision we also

discuss many tools for maintaining and

improving Vision across the lifespan

ranging from behavioral tools so

specific Vision tasks and exercises for

the eye that you can do that are known

to improve or maintain your vision as

well as specific surgical procedures

such as LASIK surgery we get into all

the details of for instance how often to

do these various eye exercises how long

the benefits are maintained as well as

age-related considerations for things

like Lasik eye surgery we even get into

how to best clean your contact lenses

whether or not to use disposable contact

lenses or other forms of contact lenses

we also discuss things like dry eye and

the best remedies for dry eye and we

talk about the scientific and clinical

data around nutritional approaches and

supplementation-based approaches for

maintaining and improving Vision so

whether or not you suffer from floaters

or dry eye or you're considering

changing your eye prescription or you

have concerns about whether or not

relying on corrective lenses is

impairing your vision and you want to

enhance your vision or if you're

somebody who has perfect vision today's

episode is going to include science and

protocols that will be highly relevant

to you I should also add that if you are

somebody who suffers from or who has

family members who suffer from diseases

of the eye that can impact Vision such

as glaucoma retinitis Pigmentosa and

macular degeneration we also delve deep

into the discussion about the most

Advanced Technologies for preventing and

offsetting vision loss due to those

diseases as well thanks to Dr Goldberg's

incredible knowledge his Clarity of

communication and his generosity with

that knowledge by the end of today's

episode You Will Be armed with all of

the modern information you need in order

to best maintain and improve your eye

and vision health before we begin I'd

like to emphasize that this podcast is

separate from my teaching and research

roles at Stanford it is however part of

my desire and effort to bring zero cost

to Consumer information about science

and science related tools to the general

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now for my discussion with Dr Jeffrey

Goldberg Dr Jeffrey Goldberg welcome

thanks it's great to be here you and I

go way back

we will spare people the discussion

about all of that but

I'm really excited for today's

discussion because I get a tremendous

number of questions about vision and Eye

Health and of course as a neuroscientist

who has worked on the visual system I

sometimes have answers or partial

answers but more often than not I don't

have the answers

and yet I'm confident that you do or

that if you don't you can direct us to

the proper place to get those answers so

to kick things off I want to ask you

what was one of the most commonly asked

questions when I solicited for questions

in anticipation of this episode which is

how early should one do an eye exam on

their child and how regularly should we

all be doing eye exams

also

is the fact that I think I can see

normally confirmation that I can see as

well as I think I can so that's really

three questions but baby comes out do

they check their eyes right away and if

so how and how often should they check

and what kind of information is there

yeah it's as a great question it's

obviously something that touches us all

so the the answer that really differs a

little bit uh at the different stages of

Life first of all every every baby gets

an eye exam or should be getting an eye

exam and uh one of the main things that

you really just are screening for right

when that baby is born right in the

nursery right in those first few days is

to just look for a red reflex you know

when you take a camera picture a Flash

picture and sometimes you get red eye

that's actually the light from the flash

as you know reflecting against the

retina coming back out of your eye it

looks red and

um and a red reflex is actually very

normal that's that that's great and if

you have a one of a number of

diseases in the eye that can present

even in babies even in newborn babies

including most concerning but thankfully

least common retinoblastoma which is the

most common pediatric eye cancer which

again thankfully is quite rare uh those

babies won't have a red reflex in that

eye it'll be kind of a whitish or gray

reflex and so even just that first

little you know doctor's taking the

little pen light and even just flashing

it in that's in the baby's eyes so

that's that's that's our first eye exam

and hopefully we've all had that and

hopefully every baby being born today is

getting that getting that first eye exam

is really just looking for that red

reflex

uh it's not typical as long as that's

looking good

um to worry about getting an eye exam

from there kind of through

um childhood like maybe early Elementary

School unless they your baby is

presenting with one of a number of

features that parents often pick up on

for example as the baby's aging through

those first couple of years you know

through the first couple of years babies

actually don't have great visual Acuity

and so as they're aging over those first

couple years it's normal for them to

have you know roving eye movements for

example be searching their environment

but over those first couple of years if

parents start noticing the baby isn't

you know isn't uh making eye contact or

looking where a sound is certainly if

they have what's called nystagmus like

these rapid flickering alternating eye

movements uh anything like that of

course you're going to trigger trigger

an eye exam but otherwise most babies

other than their pediatrician doing that

red reflex check when they're in for

their regular well child checks uh

that's really all that's uh needed

through that when most kids get to

elementary school age there will often

be often done at the schools and

amblyopia screening exam if kids eyes

either if one eye doesn't see that well

like maybe you're very nearsighted or

farsighted in one eye and pretty normal

sighted in the other or the two

refractive errors are quite different

from each other that can lead to a

condition you've talked about on the

podcast before called amblyopia which is

probably one of the more common or most

common eye diseases of children

or if the eyes are in a line you know

our eye muscles and the Brain behind

them are really responsible for keeping

the two eyes looking straight ahead and

if that's not working properly and one

eye is is off kilter and therefore the

image of what we're looking at is

falling on different spots of the retina

it's not sinking upright in the brain

that can lead to this disease condition

called amblyopia where that eye is no

longer talking to the brain properly and

there's a pretty easy screening exam

that can be done for strabismus the

misalignment of the eyes that kids will

do in elementary school the other main

presenting symptom of kids in elementary

school is when they admit to their

parents I can't see the board or I can't

see the teacher up front and then they

might be quite nearsighted and so that

will also trigger an exam and so those

are usually the parts for for babies for

toddlers for children school-aged

children that might reasonably trigger

an exam a couple of questions about

early eye exams and we'll um get on to

uh eye exams in older visuals in a

second but I want to interrupt you with

this question so you mentioned that um

you know there can be a misalignment of

the eyes I've seen many people's babies

where there is one eyeball that seems to

be kind of drifting around and then it

might correct but sometimes they'll have

a we don't want to get technical here

for our listeners we'll keep it General

but either convergent eyes or one eye

converging cross eyes or walleyed you

know again using uh that non-technical

language here

um and my understanding is that the

brain is taking that information in and

it's very plastic it's changing at these

early stages of development and that

it's fairly critical to get that stuff

corrected early on because if you wait

too long the brain can essentially

become blind to the the um or rather the

the brain cannot learn to handle the

proper alignment so in other words if a

kid has cross eyes

crossed eyes excuse me and they're not

corrected uh until their 20s it's

possible that they will never recover

normal vision whereas if you recover if

you align the eyes properly early in

development they can indeed recover

Vision how early can and should one

consider getting those eye realignments

done yeah yeah pretty much right on what

they'll do is if they detect any eye

misalignment and sometimes parents are

are good at noticing that and sometimes

you take a picture and one eye got the

red eye reflex and the other one didn't

and sometimes people notice that their

kids eyes are sort of turning in it

seems like too much

um sometimes there's what's called

pseudostrabismus which is where actually

depending on your Anatomy if you have a

little extra skin sort of on the inside

corners of your eyes it makes your eyes

look turned in when actually they're

straight but if your eyes are actually

turned in or slightly less common in

children more common in adults

misalignment turned out

it's really important to correct that

early and the reason is as you were

saying the brain starts ignoring it it

fails to fully develop the straw wrong

connections from the for the data coming

in from one of those two eyes into the

brain and if you pass certain sort of

thresholds during development during

childhood without correcting that

connectivity getting those two eyes to

work together properly you can

permanently lose that

um and so we use sort of we used to use

very sort of uh you know gross numbers

like it's fully correctable if you can

intervene before age three it's partly

correctable if you can intervene before

age six you got a chance before age nine

but it turns out in follow-on studies

that even kids into their young teens

have a shot at correcting that I brain

connection that amblyopia that that loss

of vision uh that that can occur during

early development so even if you're only

you know unfortunately detecting that

later on in childhood or even sort of

the tween years or early teen years it's

still worth a try to really push to

um retrain the weaker eye and then also

realign the muscles so that they can

work together to keep the eyes focused

I'll tell you it's interesting and

there's a lot more to learn about brain

plasticity and probably a lot of really

cool new

therapies yet to discover that could

reopen what's called critical period

plasticity this this this plasticity

that we have during development that

kind of goes away as we age and and that

critical period plasticity as you know

has been the best studied actually in

the visual system and the idea that we

could reopen that is really fantastic

but for different parts of that ibrain

connection there's different periods for

critical period plasticity for example

even if you get the amblyopic eye to see

well again and then you realign the eyes

and now they're working together a lot

of kids will never recover full depth

perception stereopsis the use of two

eyes to see depth for example so why

that part of the brain doesn't

correct as well as the visual Acuity or

central vision part of the brain I'm not

sure if we understand that yet

I'm going to ask for a curbside consult

as sometimes called right now by telling

you a story when I was a kid I went

swimming without goggles and I had one

eye closed and the other eye open and

closing as it went in and out of the

water because I'm a deficient swimmer

and I only breathe to one side

unless I really consciously forced

myself to breathe to both sides in a

freestyle swim got out of the pool and I

was seeing double

it was pretty eerie and then it became

downright scary because I didn't recover

my double vision until they patched one

of the eyes to forcing me to use the

other eye that had been closed the

entire time

and fortunately this was done early

enough and it I was young enough that

within I think it was about a day or so

I restored what normal vision however my

depth perception is terrible

um I'm the kid that you know Fly ball

was hit to me in the Outfield and it's

coming it's coming and then it hit me

this is why I've generally focused on

foot Sports throughout my entire life as

opposed to you know precise hand-eye

coordination I'm better at throwing

darts and things with one eye closed

than I ever would be with both eyes

maybe that's true for most people

question I have is

is it true that even just a few hours of

misalignment of information to the two

eyes early in development can

permanently rewire the brain unless

there are some corrective measures such

as patching up one eye and the example I

gave is just one but for instance if um

uh you know someone injures you know

gives a scratch on their cornea and they

close they patch the eye and the person

happens to be 10 years old is it

important to then patch the other

healthy eye after the the um you know

the scratched eye is feeling better in

other words how critical is it to ensure

the balance of information coming into

the two eyes even on the order of hours

or days yeah your story is uh it has

some features of uh you know totally

usual how we think about misaligned eyes

leading to amblyopia where one eye is

weaker patching the strong eye so the

weak eye can recover but not necessarily

fully regaining depth perception and so

that part of it is you know quite

stereotypical the part of your story

that's atypical is that for most kids

um an hour to let alone minutes an hour

to even an hour to a day if you were I

don't know if you were a young kid and

you just really were training up on

throwing darts and you were just keeping

one eye closed to throw the darts you

know really practicing for an hour a day

it'd be very unusual for that to trigger

this kind of either strabismus

misalignment of the eyes let alone

amblyopia and the strabismus is what's

giving you the double vision because

they're misaligned let alone the

amblyopia of one eye turning out weaker

if I had to guess of course not having

you know done your exam before that

fateful day in the swimming pool if I

had to guess I would guess that you may

have had some intermittent business and

your brain was already getting kind of

hit

and and you neither you nor your parents

may have even noticed it it could be

happening you know at other times a day

or you're not kind of really paying

attention it doesn't kind of stand out

in the way that that that day that you

got out of the swimming pool you really

noticed it and it may not have been that

strong it may have been quite

intermittent but if you had had some

years of intermittent isotropia or

turning in of the eyes or exotropia

turning out of the eyes that just

happened here and there but was

accumulating sort of uh damage or

failure to connect over years leading up

to that day in the swimming pool and

that day just tipped you over the edge

and you've got double vision you really

noticed it that led to an eye exam and

an eye care provider and they said wait

a second this size stronger this size

weaker you've got a little amblyopia

we're going to start patching your

strong eyes so you can get your weak eye

back so for 99.9 percent of the kids who

like you know yeah they get a little

corneal scratch or they're patching one

eye closed or or uh you know anything

that's sort of a rare event like that

nothing to worry about parents don't

have to worry kids can be kids they can

play they can do that kind of thing and

uh and not have to worry and and it's

unfortunate that we can't tell in

advance

which kid's been having the intermittent

amblyopia because we don't do a standard

eye exam on every five-year-old who's

not complaining of anything but but yeah

so that's a that's an unusual case in

yours and if I had to guess I I would

bet that you were having some sort of

subclinical untracked Uncharted

unnoticed maybe strabismus leading up to

that point okay great thank you you can

send me a bill at the end

um

along those lines

I'm 47 years old so I was part of the

generation that grew up with some

computers in the classroom but not a lot

nowadays

kids from a very young age are looking

at iPads and

phones and screens and things very close

up and there is a wealth of experimental

animal data showing that if you limit

Vision to just close range that the

eyeball lengthens and therefore the

visual image Falls in front of and not

directly onto the neural retina the

essentially the light sensing portion of

the of the eye and those animals become

myopic or nearsighted

what can we say about the environmental

conditions in which kids are seeing

from the time they're born through let's

say adolescents and their teen years in

terms of

how their visual system wires up and are

there any recommendations that are

coming from the scientific literature

clinical studies clinical trials excuse

me or otherwise that indicate what a

healthy visual environment consists of

yeah yeah that's a great question and

actually it's really relevant these days

because uh you know myopia is so common

uh it's more common

um

an Asian populations you know it's

called an epidemic in China in

California we have a lot of Asian

Heritage or Asian Americans and so we

see a lot like at Stanford we see a lot

of

um you know myopia in kids on adults and

really starting to get thoughtful on the

science of myopia control how do we how

do we provide the right environments now

what's interesting is that for decades

the Assumption some of the data really

led us to the path of thinking like gosh

the more you spend near activities and

these are Mouse model experiments like

you described but also well-designed

human cohort studies you know figuring

out like asking you know kids and

families like how long is your kid

reading or in front of the computer how

myopic are they how nearsighted are they

versus how much time is your kid in

front of the computer doing near work

how myopic or nearsighted are they and

these well-designed cohort studies did

Point tour words this concept that if

you do too much near work as a kid that

you're more likely to develop

nearsightedness as you get through those

those sort of you know uh pre-teen and

even into the teen years which is when

most of that myopia progression or

eyeball elongation is actually happening

to cause nearsightedness

it's only been in the last few years

that some really exciting Studies have

actually pointed in a slightly different

direction

and that's that maybe it's not all not

to say it's not about near activity but

maybe it's not all about near activity

maybe it's actually a little more about

the kind of light we're getting into our

eyes and I think you've talked about

this before and it's really important

when they've now studied and asked the

kids instead of just how much near and

how much far are you doing how much time

are you spending indoors in indoor

lighting which doesn't have full

spectrum light in a typical indoor

environment versus how much time are you

spending Outdoors

playing in the yard you could be reading

outside but what are you just what kind

of time are you spending outside and and

of course when you're outside in

sunlight even it's in direct sunlight

you're getting a different spectrum of

kind of Full Spectrum Lighting from the

sun and it looks like it's pretty clear

now actually that it has maybe more to

do with outdoor lighting time than just

near work and so I think that you know

we we've we've actually already seen the

first couple randomized controlled

trials where they're having kids

intentionally spending time Outdoors

versus sort of Standard Life which you

know is going to be often much more

indoor time and uh and seeing some

effects you follow those kids over a

couple of years and the kids who spend

time Outdoors are are progressing in

their nearsightedness less like they're

they're nearsighted prescription is not

getting as strong as the kid kids who

are spending more time indoors and

there's some pretty good biology that's

getting worked out going back to animal

models more about about how that might

be working in the retina in this inside

the eye but it's pretty compelling uh

concept and and so you know as a parent

uh you you may want to be you may want

to be telling your kid like okay yeah I

want you to read that book or you know

if your kids plan on the phone or

something like that or the iPad or

something like that they're allowed that

time okay you can have that time but I

want you to spend some of the time that

you're doing that Outdoors are there any

thresholds for the amount of time that

one would suggest their child be

outdoors to get that full spectrum light

it's a great question you know we talk

about cohort studies where we just ask

people what are they doing and there

seems to be you know a little bit of

what we would call a dose dependent

response maybe the more time Outdoors

might be better we don't know if there's

an upper limit like gosh if you go over

two or three hours there's no additional

benefit talk about that cohort studies

the real gold standard for answering

these kinds of questions are randomized

controlled trials and specifically

placebo-controlled or or a control group

that's not getting the intervention

that's our highest level of evidence for

clinical evidence for for any of this

kind of science when we're talking about

humans or pre-clinical models in the

laboratory and the study that hasn't

been done yet to really answer that

question is to randomize kids to telling

this group of kids you just do your

normal life tell this group of kids we

want you outside an hour this group of

kids we want you outside two hours a day

this group occurred three hours a day

and see between the groups is there a

big difference like we have pretty good

evidence now from the studies that have

been done that the difference between

zero

and one or two hours is clearly There is

five minutes enough is five hours better

I don't think we know the answers to

those questions yet like what's the

right dose but there's probably at least

some dose dependence to that and it I

can imagine it's a little bit hard to

tease apart the near far viewing from

the indoor outdoor because yes of course

a child could be outside on an iPad up

close

but it's hard to imagine that at some

point they aren't seeing off into the

distance far viewing as it's called and

the reverse is also true if you're

indoors unless you live in a very very

large home or you're staring off a

balcony far viewing is much harder to

achieve yeah so it's and perhaps it

isn't important to isolate these

variables although I can see the

challenge in developing a really good

clinical trial randomized clinical trial

for this meanwhile I I you know I'm con

I'll go into the grave shouting you know

or saying rather and suggesting that

people get some morning sunlight in

their eyes to set their circadian rhythm

um but far viewing a few at least a few

minutes and ideally hours per day or a

mixture of near and far viewing by being

outdoors just seems like a good thing to

do regardless of age so are there any

data in older people not necessarily

elderly but older people so um people in

there from say 25 years of age into

their 60s or 70s that getting outdoors

and getting this full spectrum light is

healthy for the eye in ways that are

separate from the known healthy effects

of doing that on circadian rhythm

setting yeah yeah the Circadian Parts

pretty clear the

and most patients and most in most

people the new the development of

nearsightedness happens a lot until age

10 little more through age 20. a little

more than that into the in you know in

through the 20s up to 30. tiny bit in

the 30s up to 40. but usually by those

later ages your prescription might be

changing a quarter of a diopter that's

the measurement that we use when we you

know give you your glasses prescription

a quarter of a diopter half a diopter it

could get a half after more nearsighted

or less nearsighted you know once you're

aging into your 40s 50s and Beyond so

most of the action on nearsightedness

development is actually really happening

in the younger ages so again the the

premise of intervening in an older

person and I'll just include you and me

and older people for the sake of this

definition as much as I'm reticent to do

that in general

um I think the the premise of Inc of of

sort of light modulation from

nearsightedness in older people is

probably probably not so strong I think

there are a lot of other benefits you've

talked a lot about circadian rhythm

there are so many health benefits to

exercise and you know if you're getting

Outdoors there's a good chance you're

going to be walking or bicycling you

know so so exercise value for the health

of our eyes and the rest of our body is

clearly there

um but I don't know that there's really

a strong premise that you're going to

change your glasses prescription you

know in our 40s or 50s or Beyond I'd

like to take a quick break and

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probably worth touching on some of the

do's and some of the don'ts for Eye

Health generally and then I promise I'm

going to get us back to adult eye exams

because I have a lot of questions about

that

I can imagine that it's probably not a

great idea to be exposed to extremely

bright light and this is why people who

weld wear eye Shields but of course most

people are not welding

um

what other sorts of environmental

conditions are detrimental to our vision

health across the lifespan including

brightness of light we talked a little

bit about near far obviously we want to

keep toxins and acids and solvents and

things out of the eye but what do you

see

I'm not because hopefully not commonly

but what are some of the things that you

feel might not be discussed enough in

terms of Eye Health yeah you know I

think at all ages eye safety is

something that we don't talk about

enough

um you know our eyes are delicate the

front surface of the eye the cornea the

Clear Window that lets the light go into

your eye that's a delicate very

sensitive structure it's thin maybe a

millimeter at the thickest a half

millimeter in the center of our eye

uh the retina is it it's neural tissue

this is like really an outgrowth of the

brain this is very sensitive it's

subject to degenerative disease and

injury our eyes even if they just get

hit can get very inflamed our eyes can

be more inflammatory than a bruise on

our skin on our shoulder might be so eye

safety is a big one and people who are

working in certain industries

um you know anyone who's doing any metal

grinding people who are even just

gardening you know and if you're if

you're doing some significant gardening

and cutting and you could you know Fleck

a little bit of dirt you know there's a

lot of there's a lot of for example

fungus that lives in the ground natural

stuff it's all very normal in the in the

Earth but you know our eyes aren't

really made to absorb that fungus and

and have have a piece of dirt kind of

stick in our eye like that and so people

are at risk I think for you know for not

and we see too much kind of

really unnecessary eye injury eye trauma

that if people wore either their glasses

because they happen to wear prescription

glasses or goggles or for more advanced

work you know safety goggles of course

um if you're sanding doing wood shop

projects anything like that sawing

including you know again in the garden

cutting things

um you know I think I think eye safety

you know eye trauma is a big one and you

know we probably see one or two

um what we call open Globes a week come

into the Opera into the emergency room

and

um you know those are tough because you

know again the eyes delicate and it can

do a lot of healing but but not infinite

right and so we really you know that's

that's one that I think is really

an untapped opportunity is just a little

more education around

um around eye protection protecting

against eye trauma what about eye

cleanliness there's some pretty dramatic

videos also I've put some of these on my

Instagram handle of these are MRIs of

people rubbing their eyeballs and people

really getting a sense of first of all

a restatement of what you said getting a

real sense of just how much the eyes are

an outgrowth of the brain because of the

op when you see with the optic nerves

and all their beauty and the eyeballs

moving around as someone rubs their eyes

I have to imagine that rubbing your

eyeballs a little bit isn't bad but I

actually called you I don't know if you

remember when I was a junior Professor I

woke up from a nap one day and I

couldn't see out of one eye I was

freaking out so of course I called you

and I had pressure blinded Myself by

falling asleep on my hand or something

like that and you assured me that my

vision would come back and indeed it did

so you play dual role of ophthalmologist

and psychiatrist thank you and indeed I

can see out both eyes

um now

um but

rubbing our eyes getting gunk in our

eyes you know I think unless somebody

has lost their Vision temporarily

it's hard to imagine this is like a big

deal but when it happens it is truly

frightening we're so dependent on Vision

so um you know what are your

recommendations about rubbing or not

rubbing eyeballs about

um hand washing and cleanliness and also

how do you wash an eye properly yeah do

you use soap and flush it with water or

do you just flush it with water or

should you not even do that should use

saline I didn't realize these might

sound like low level questions but these

are the things that people deal with on

an all too frequent basis yeah you know

for most people most of the time

actually the eyes are a very good clean

environment and actually are tears are

are contain enzymes that help break down

bacteria and bacterial toxins and so for

most people regular eye washing doesn't

have to be any part of their standard

routine in terms of the surface of the

eye the part of your eye the conjunctiva

uh over the whites of the eyes

underneath the eyelids anything

underneath the eyelids it's pretty

self-cleaning and actually our tear

production and blinking is very good at

keeping our eyes clean the eyelids

eyelashes can be another story and

especially as we age uh we can you know

like our skin is breaking down a little

differently than when we were younger

you can develop what we sort of

nicknamed scurf which is like kind of

little dead skin bits that accumulate

around the eyelashes a lot of people

develop what we call blepharitis which

is just just means inflammation of the

eyelashes yeah and for that doing some

eye scrubs is a good idea they actually

sell little pads that you can buy kind

of little that you rip open and you can

use to kind of lightly clean the

eyelashes but you can also just use like

a No More Tears baby shampoo just pump a

little bit into the palm of your hand

once or twice a day let a little uh

dilute it with a little water and under

the sink and either with your finger or

an edge of a washcloth just very lightly

rub the eyelashes what I like to do with

the eyes closed with the eyes closed and

don't scrunch them closed too tight

because you're actually burying the

eyelashes when you do the roots of the

eyelashes when you really scrunch so

just gently close your eyes just you

know real gentle closure and then just

lightly scrub it shouldn't be abrasive

you're not trying to exfoliate the

eyelids or eyelashes in any way just

lightly rub with that kind of dilute No

More Tears baby shampoo and that can

really help people with their eye

Comfort if you feel like you've got

something in your eye your ideal eye

wash is actually going to be a sterile

Salient solution a saltwater solution

that you know they sell little bottles

over the counter eye wash Solutions like

that a lot of people wear contacts will

have that kind of eye wash solution just

a sterile saline eye wash just pure salt

water doesn't have to have any other

chemicals or preservatives in it you can

of course use not actual uh seawater or

salt water not salt water thank you yeah

not salt water out of your salt pool not

salt water out of the ocean but like a

saline salt water that's available in a

sterile now you can also just use

artificial teardrops and some of those

common non-preservatives some of those

come preserved versions those are all

also completely safe in the to use in

the eye and there you can you know you

can sort of Spritz into your eye you

know hold the lid open and give it a

little Spritz if you feel like you've

got something in your eye a piece of

dirt or A Lash that's not coming out

just to rinse it but but having like a

regular routine you know you're not

going to hurt anything with the

occasional eye rubbing we all do these

things just kind of as a you know even a

nervous habit or just absent-mindedly

you know you might you know scratch your

arm or rub your eyes or things like that

that's fine you're not going to hurt

anything there are conditions where

people sort of develop kind of a almost

like a psychological habit there are

certain conditions where people actually

do too much eye rubbing it can be

dangerous if you're in that group but

for the regular run-of-the-mill every

day occasional I rubbing fine if you

certainly if you get a lash in there and

you're trying to rub it and blink it and

tear it out and again in that situation

you can use some artificial tears

wedding drops saline drops those would

be the way to do it what an incredible

tissue the way you describe it you know

the self-cleaning and yet so delicate

a piece of the brain literally lining

the back of each of our eyes like like a

pie crust I mean it's a really

remarkable

um biological system of course I don't

have to tell you that it's just it it

never ceases to to amaze me

let's talk about eye exams in adults

so

people are aware presumably that they're

optometrists and ophthalmologists I

think it's important that we Define

their different and also overlapping

roles and

for those that you know are past High

School age probably not getting eye

exams unless they're sensing a problem

perhaps not even with blurry vision or

difficulty seeing at a distance but

sometimes just what feels like fatigue

of the eyes or a hard time maintaining

alignment of the eyes

um so how often do you recommend people

get eye exams what is a true regular eye

exam and is it important that people go

to an ophthalmologist or will an

optometrist suffice typically

optometrists are a little bit easier for

most people to access because there's

usually one someplace near an eyeglass

store so what are their roles how often

should we get our eyes checked yeah

um optometrists and ophthalmologists do

have very overlapping roles in being Eye

Care Providers there are something over

40 or 50 000 optometrists in the United

States or somewhere around 20 000

ophthalmologists in the United States

optometrists get an optometry degree

they often have OD after their name

ophthalmologists usually went you know

went to medical school so they either

have an MD after their name or they kind

of a do version of a medical degree and

uh and then optometrists will have done

additional clinical training in that

area in their area of Eye Care provision

ophthalmologist MD doctor

ophthalmologist Eye Care providers in

addition to that training will have done

surgical training in Ophthalmology

um now there's a lot of overlap and

um in both scenarios uh you can be

getting your sort of General exam taken

care of maybe a screening exam I think

that there's been a traditional

differentiation between optometrists and

ophthalmologists with optometrists

providing a little more of the primary

care eye screening maybe managing early

disease common diseases as well with

more advanced disease often sort of

upgrading to perhaps specialist

ophthalmologists in those areas but that

distinction has been declining over time

it's still true that in I think most if

not all states only the MD

ophthalmologists surgeons can do eye

surgeries but both both groups of eye

care providers can diagnose both can

prescribe appropriate eye drop

treatments including prescription eye

drop treatments for for many of our

diseases eye diseases

and um and in some states

optometrists have successfully lobbied

for uh sort of expanded rights of

providing Air Care Eye Care and again

um access to care for you know the

regular person wherever they may live is

is the most important element and so

being able to access eye care whether

it's with an optometrist in your

community or an ophthalmologist that may

be in your community or maybe at a

distance I think that's the the really

important thing is to access care now

kind of like we were talking about with

kids uh if you're in your teens 20s

maybe even 30s and not having any

problem you've got no complaints you can

see a distance you can see it near

um you know so you can read without

classes you can drive without classes

um you're not having any eye pains you

know pains around the eyes you know

redness of the eyes you may never

present to an eye care provider through

the first four Decades of life

and almost all the time it's going to be

okay right if you're not symptomatic the

chance you've got some terrible lurking

disease in there is low

but we do wish that we had a little more

screening going on because there are

some diseases glaucoma for example my

specialty the two main risk factors for

glaucoma are increasing age and that

usually presents you know in most cases

actually after age 40 but also

increasing eye pressure and if your eye

pressure is too high you can't feel that

that won't feel funny to you if it sort

of slowly is crept up over the years and

so from a screening perspective it is

good to get some kind of screening exam

could be at a public health fair could

be that you go into the local

optometrist just say hey I've never been

checked I'd like to be checked once make

sure everything's good could you ask for

sorry to interpret could somebody say

I'd like my pressures checked as I

recall the optometrist they're going to

do a puff test so they're going to blast

some air get a sense of how how rigid or

or soft again using non-clinical

non-technical language here the eyeball

happens to be

um not right now by the way I'm sure

there are are several hundreds of

thousands of people who are with eyes

closed touching the sides of their

eyeballs and I'm only half joking please

don't do this folks I'm given the

conversation we just had about eye

cleanliness and eye rubbing but my

understanding is that the old fat truly

old-fashioned eye pressure exam was you

would close your eyes and the

ophthalmologist would gently press to

see whether or not your eyes were more

rigid than last time yeah is that right

yeah that's called ballot mint and you

can kind of you can you can kind of just

take one second if you're listening and

press on your eyes just very lightly and

you there's a little give of course the

eyelids part of that give but but it's

not it's not like rock hard and if we

press and it feels under the eyelid like

gosh something under there is a rock

hard then we know something is wrong

that is way too high pressure if it's

raw card but I'll tell you our ability

to differentiate the fine points of eye

pressure other than Rock Hard or not

rock hard is pretty limited so yeah the

optometrist office or the

ophthalmologist office office as part of

a comprehensive screening exam they'll

check the eye pressure they'll look at

the surface of your eyes make sure

everything's looking healthy there

including the eyelids and lashes and

they'll look inside the eye and be able

to screen for these diseases that way

too in addition to checking if you're

complaining of any you know blurriness

at distance or at near now after age 40

or so a lot of people will present to an

eye care provider because we all get

what's called presbyopia and presbyopia

just translates to disease a vision of

the agent so you know myopia is our word

for nearsighted hyperopia is farsighted

actually amatropia means normal sighted

so I can see it distance without any

glasses I'm amitropic

but then we all get presbyopia and as we

age the lens inside our eye that's

helping focus light onto our retina gets

stiffer

such that our eye muscles are no longer

able to relax and reshape that lens and

we're not as good as we age at

moving our Focus from distance Vision

distance Vision by the way is basically

anything three feet or further away

You're basically viewing light rays

coming from Infinity once you're past

three feet so three feet or further

being able to focus that into 14 inches

or 12 inches which might be a normal

comfortable reading space for you

we lose that ability to flex our lens

relax our lens uh refocus our lens from

distance to near and most people around

age 40 could be a couple years before

could be five or ten years later that

you notice it but sort of around that

time you start needing reading glasses

you need a little extra even if you can

see fine at distance and don't need

prescription glasses for distance you

need a booster you need reading glasses

for near I don't know if you're

experiencing this yet and yeah I'm

really intrigued by this but maybe you

could clarify when you say reading

glasses do you mean just a magnifier

because I use a you know a 0.5 or a 0.75

magnifier for reading but I try and rely

on them

as little as possible and I want to get

to this about using glasses as a crutch

and the problems with that I have a

story about that too you know it's no

coincidence I decided to work on Vision

I mean after all

um I had a bunch of vision issues that

fortunately are corrected but you know I

I do experience for instance when I wake

up in the morning if I look at my phone

which by the way folks I try and get

outside and see sunlight first before

ever looking at the phone but I'll

notice when I first look at my phone in

the morning that I can see it very

clearly through my right eye but that if

I cover my right eye my left eye is

extremely blurry to the point where I'm

like oh I'm calling Jeff you know I'm

I'm afraid but then over the course of

maybe 10-15 minutes it resolves and I

don't think it's because something's in

my eye I don't think it's pressure of

having slept on that side I don't think

it's a lubrication of the eye issue

um but the two eyes seem to come into

Focus so to speak um at different rates

early in the day and if I pop my readers

on I can see right away so I will use

readers late in the day often

um if I want to read at night or

something that's right just it feels so

much more relaxing I feel like like I

can finally relax whereas otherwise I

realize that I'm straining in order to

see does is there any um clinical

clinical data and what I just described

yeah you know Andy I'll tell you my

story that's like that and

um we were living down in San Diego when

you and I were both professors at UC San

Diego

and uh we had moved into a house and I

found a pair of glasses a pair of

reading glasses uh in a closet and you

know we asked around you know did any of

the grandparents uh leave some glasses

behind nobody seemed to know who they

were so we finally just decided like

well I guess the people who moved out of

the house just left a pair of glasses

you know in this in the back of this

closet

and then I tried the glasses on

and I looked at my phone up close and

was just like oh my God wait a second I

didn't realize how blurry my near Vision

was and this is back I was about 40 42

something like that so

so I didn't even realize until I put on

the readers and these were

you know 1.25 magnifiers you know so

awesome yeah

and I'll tell you

I got addicted because who doesn't like

good Vision right right I mean oh my God

now I can make the type smaller on my

phone I can you know it was wonderful

and you can relax a bit I mean the

musculature that's responsible for for

moving the lens and focusing the eye and

then all this extraocular musculature

and we forgot I mean I'm definitely

going crow's feet

um around my eyes uh probably because I

you know squint or something but you

know just the ability to relax one's

face it just feels like you know more

more energy I feel like can be devoted

to what we're actually looking at yeah

we're not making light of this yeah well

pretty soon I just kept that one pair of

glasses with me all the time and I would

just keep them in a pocket and whip them

out whenever I was you know working at

near using my phone at a little greater

distance like a typical computer

distance I could still see the computer

fine so it really started for like kind

of that close-up phone it was it was I

could get into here but not all the way

into here

and um yeah and then pretty soon I was

just totally addicted and so you know

then I had to go buy 10 pairs and leave

them one by the bedside table you know

one in the car one in the computer bag

one on everything I work at yeah because

I'd leave them anywhere and forget them

yeah exactly you know yeah

so

um yeah so

whether using the readers

accelerates the progression of

dependence on the readers is still uh

not you know that's still up for debate

you know some studies say maybe yeah

some studies say maybe no but certainly

psychologically we get addicted to good

easy vision and if you don't have to

squint and if you're not straining your

muscles and all of a sudden the text on

your phone looks crisper again uh boy

that's addictive you're gonna like good

vision and so it feels like you're

getting dependent and how much of that

is changing the eye muscles and how much

of that is just the psychology of

wanting to have good Vision I think

probably the jury's a little bit out on

that point but point being you're either

either way your dependence will grow and

as you continue to age 40s 50s up until

about 60 65.

the ability to shape that lens gets

weaker and weaker and weaker and so you

need to move from the 0.5 to the 1.0 to

the 1.5s and to the coke bottle to the

code well thankfully not you eventually

max out at about plus 2.5 or plus three

because that's the amount of extra

refractive power that you need in

magnifiers to take the equivalent of

your Infinity viewing and bring it up to

14 inches to read it near basically you

need a plus three and then you don't

need any

lens eye muscle action whatsoever so you

kind of max out around 2.5S or threes

so because most people will hit this

somewhere in their 40s this sort of like

gosh I'm having trouble on the phone

I think most people actually use that

that's like kind of the first time for a

lot of people they're like well I guess

I should go to the eye office right see

the optometrist or maybe ophthalmologist

and when they go in they should be

getting the standard in either of those

offices will be to give you a full

screening exam including maybe it's the

puff test or a blue light test or a

little pen that can check your eye

pressure and having a look inside and

seeing if you're retina optic nerve look

healthy it's kind of screening for all

the main diseases and so and they'll

tell you at that point hey you look

great if you feel like your glasses

aren't doing it for you in a year or

three years come back or they might say

hey I've detected something I'm worried

about you and they'll set up a routine

for your ongoing Eye Care

assuming that somebody doesn't have

um you know some form of amblyopia or

the need for some a really robust

corrective lenses

and they are already using readers let's

say a plus one

or so you know plus one plus or minus

0.5 reader

would you recommend based on my

experience and based on your experience

that people strive to avoid using them

for as long as they can because in some

sense if that's the recommendation then

the recommendation is that people kind

of deal with the fact that they're

seeing a little less well or a lot less

well than they possibly could so I'm

assuming that people can still drive

well people can still read but it

involves a little bit more effort in

other words are we weakening Our Eyes by

using these these readers I I realize

you said that the data are a little bit

mixed but as long as one can perform

their required daily activities would we

be better off

delaying the use of readers

there's two important answers to that

question one is regarding the lens and

the eye muscles that control the lens

and it's entirely plausible that's what

I was saying kind of the data is mixed

on but it's plausible that if we would

just exercise like work a little harder

kind of not use as strong a reader as we

want or not use that reader as often as

we might really enjoy uh are we

exercising those muscles and kind of

exercising the ability to to stretch

versus relax the lens and kind of slow

the progression from the 1.0 reader to

the 1.25 reader to the 1.5 reader Etc

right and so that that's why I'm saying

the data is mixed but there's a good

premise that maybe if you're exercising

but let me give you the on on the other

hand it's probably ideal

to give your retina and your brain the

sharpest visual signals you can

so why hamstring your retina and your

brain and your vision and your enjoyment

and ability to read or do near work by

constantly undercutting the the reading

glasses or leaving them out or you're

not helping the whole back part of yours

maybe you're maybe you're helping the

lens but you're definitely not helping

your retina and brain by feeding it

blurry information all of that time so I

actually think just give in use the

readers have your enjoy your Best Vision

all the time and if that means wearing

glasses and by the way if that means

that you're going to have minus two

glasses for vision and you'll eventually

need minus 250s for distance Vision or

if you're going to need readers 1.5

readers now and in a few years 2.0

readers okay so you'll get the next

reader it's it's it's actually not a big

deal you can you can you know you're not

you're not hurting you're probably

helping and in the meantime it's an

enormous enjoyment to actually have good

Vision all the time right so so I

actually counsel people

just wear the glasses that work best for

you you know you're only minimally

changing how your prescription is going

to change over time very minimally so

just enjoy your Best Vision even if it's

using readers for clothes or

prescription glasses for far

I appreciate that recommendation I do

enjoy you using the readers at night it

really helps for all the reasons I

mentioned before

I've noticed that driving at night

presents an enormous strain on my visual

system and I've noticed this for a

number of years are there any I know

there's something called stationary

night blindness I don't think I'm

stationary night blind

um I think the mutation for stationary

night blindness was identified in the

Colusa horse or something like that

these were horses that you could walk up

to very easily and they wouldn't even

see you until you're right there

someone's going to correct me on this

it's the internet but I think that the

mutation was identified

um Etc but I don't think I'm stationary

night blind but I do find that driving

at night I get very fatigued and then

I'll sometimes even wear my plus one

readers when I drive at night which

removes the fatigue even though I'm

looking more or less at a distance are

there some conditions that make it hard

for people to see at night for which

they would want corrective lenses

um and what what sorts of biology

underlies that assuming that somebody is

not stationary night blind or a Colusa I

think is the name of the breed horse

yeah that's a great question you know we

for the for the optical defects in our

eyes most or many of which can be

corrected with just having the right

prescription lenses we can get away with

it without using those Corrections in

brighter light

and so during the daytime

um you know you could be slightly blurry

you know if I have a real bright light

uh and a good high contrast book you

know with black letters on the white

page I can get away with reading that

without my readers unlike if if I'm in

dim light then I feel and that might be

kind of what you're describing if you're

reading at night you actually prefer to

use the readers a little more even at

night because we can make up for a lot

of that blur if we just have bright

enough signal and contrast coming into

our eyes makes sense yeah so when you're

driving at night and noticing this this

might be revealing a little bit of a

need for glasses now I'm not suggesting

this is the answer but far more common

than having congenital stationary night

blindness would be being what's called a

latent hyper rope okay now we talked

about already how the lens inside our

eye goes from focusing it distance to

then we squeeze the muscles the lens

actually rounds up and allows us to

focus it near

some people's Optical system of their

eye is actually wired or designed or

sort of set up in length not for regular

distance which would be anywhere from

about three feet to Infinity

but it's actually designed it's actually

tuned for being beyond Infinity which

doesn't make any actual sense when you

talk about it but just the Optics of the

eye at their best Focus are actually

focusing the light behind the retina and

and if you're doing that when you're

younger you're actually using some of

your focusing power to to use those

muscles strain those muscles relax that

lens round up that lens and have your

vision Focus From Beyond Infinity to

normal distance like distance vision and

so if you're a latent hyperope you are

constantly using those muscles and again

if you're tired it's the end of the day

your muscles are feeling a little

fatigued uh your latent hyperopia or by

the way if you've had a drink or two

alcohol can do this too your latent

hyperopia can kind of kick in especially

as we're age and we're not as good at

refocusing that lens anyway and now all

of a sudden your vision is kind of

reverting to its natural state which is

slightly out of focus at distance

because it's actually focused beyond

Infinity if you will and so all of a

sudden you put on that plus one just for

a little extra booster kick and you're

like oh yeah yeah distance vision is

clean and easy now so

I'll have to bring you into the clinic

to really be sure but you could be

exhibiting a little bit of that kind of

latent hyperopia I definitely want the

eye exam and I want it from you and I've

been called a lot of things in life um

and we can now let add perhaps latent

hyper

opiate

uh to that

I'd like to take a quick break and thank

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off another easier and again this

discussion is not designed to be an eye

exam for me but I have yet another

experience that I think illustrates the

key importance of both critical period

plasticity and the questions about

whether or not to rely on corrective

lenses and that is from the time I was

pretty young I could make my sister

laugh by deviating one eye inward so not

crossing my eyes but moving one eye

Inward and then what happened was when I

was in college and studying a lot a lot

and getting very fatigued I noticed that

this I started just kind of drifting a

little bit so I went to the campus

Health Center and they gave me a

prescription for a prism lens which of

course redirects the image but then I

noticed that this eyeball moving Inward

and I guess for those of you watching on

uh on YouTube and not just listening um

I can do this

um by just moving one eye in all right

as I can move this side yeah it's a

fairly pronounced it started to really

drift in at a relaxation State and I

started seeing double again so I thought

whoa these prism this one prism lens is

a crutch of the sort that I really don't

want crushed the glasses it broke them

and it never went back to them

um I have voluntary control over it but

that's one example where the corrective

lens can actually create a pretty

significant shift in eye position if one

relies on it so this gets back to this

issue of

um when should people Force themselves

to work with their natural vision maybe

do some more far viewing

um as opposed and certainly get outside

and get sunlight into the sunlight full

spectrum light as opposed to relying on

active lenses yeah and and you've raised

a very important distinction here and

that's the distinction between the

muscles that are inside our eye that we

use to relax and refocus the lens and

the muscles that are on the outside of

the eyeball of course inside our orbit

but on the outside of the eyeball that

turn the eyes and if everything's

working right keeps our eyes really

yoked straight and we talked about

earlier uh this possibility that you may

have been having a little bit of

intermittent esotropia or intermittent

turning in of the eyes that then

culminated on that day of a day at the

pool when you really noticed it

and your ongoing ability to actually

turn one eye in could be related to that

I remember as a kid standing in front of

the mirror and I I couldn't get my eyes

to cross even though friends could do it

and you know so you know I I was in the

losing group on that on that end you

became an ophthalmologist and then I

became an ophthalmologist and I must say

it is very reassuring that you have

excellent Vision you know I always worry

when I go to a new dentist and then I

look up at them in one moment and if

they're not wearing a mask that their

teeth are not you know pristine I think

well what am I doing here so at you know

an ophthalmologist with excellent Vision

brings me uh great comfort the toddler's

children should have shoes right exactly

um but yeah so so when to correct when

not to correct with lenses and I realize

here we haven't talked at all about

contacts we've been talking about

eyeglasses yeah let's come to contacts

in a sec if you want but yeah let me

return to your question the difference

between providing corrective lenses that

allow you to focus for near or distance

uh in your glasses so that you can go

easy on the inside the eye eye muscle

having to work so hard a lot of people

get eye strain and sort of uh headaches

even from that from not having adequate

correction that they're wearing that's

different actually especially when we're

children or again into that maybe even

into the teens and even young adult

years

from the eye muscles on the outside of

the eyes which are supposed to be yoking

our eyes straight and so that you have

them both looking at the same point in

space and and there it's actually quite

a common treatment to try to under

correct and ask people to exercise and

not just give a prism that says hey if

your eyes in sometime we'll use a prism

so the light sort of looks right to you

but rather under correct that and sort

of really force you to exercise trying

to yoke your two eyes straight together

and so that's that's in contrast and

they're actually I think many

optometrists who often specialize in in

what are the right glasses to give in a

situation like that wherever possible

especially during

uh development as our bodies are

developing as we're sort of growing in

our younger years uh take the approach

of intentionally trying to under correct

not use a prism or not use a full prism

correction uh and um to really help uh

sometimes it's also like an

accommodative reflex that your eyes are

just you're spending so much time

reading it near when you read it near

your eyes actually naturally turn in a

little bit to focus uh at that nearer so

that they can be looking at the same

word on the page and that can also if

you've got kind of too much muscle drive

you can overshoot that and so sometimes

just using not a prism but like a little

bit of a plus lens in kids just so they

don't have to work quite so hard to turn

their eyes in and sort of over exercise

those muscles these are all great

examples we're going to an eye care

provider often for these kinds of issues

an optometrist is the right first place

to start

you'd like to say that every optometrist

and every ophthalmologist is always

going to give the exact right thing for

for each kid or young adult or older

adult to do and and we wish all medical

care providers were were always right on

Target and a lot of times it's a perfect

science but a lot of times it's an

imperfect science and so it could be

that at least with you know we're now 20

25 30 years later but like it could be

that today that 20 year old version of

yourself would have been given a

different uh approach to having one eye

intermittently occasionally turning in

like that is there any real value to

um near far exercises you know so-called

pencil push-ups or a smooth Pursuit

tracking I've talked a little bit about

it before on the podcast but that was

you know some time ago so what are your

thoughts on on that is there any value

whatsoever I mean they require a little

bit of work just like going to the gym

but you know you know 25 reps a day of

near far

um especially as one is transitioning

from age 30 to age 50

um is it worthwhile yeah is it harmful

in any way definitely not harmful and

again uh you know would it slow down or

sort of uh slow down your progression to

presbyopia or needing those reading

glasses uh could be some people also

develop

um sort of uh you know a real failure to

properly turn their eyes in and so they

actually would benefit if you've been

diagnosed with that inability or having

double vision at near but not at

distance

um so that kind of convergence in

insufficiency for example then then

pencil push-ups off and get prescribed

as a way to try to exercise those skills

and you know uh in your eye muscles I

should interrupt here and just tell

people for those of you that are

listening not watching the pencil

push-up we can put a link to it in the

show note caption so it's essentially

taking a pen or pencil looking at it at

um at arm's distance and then slowly

moving it toward your nose and

deliberately working hard and it is a

bit of effort to continue to focus on it

at a close distance at some point it

will become blurry because I can't cross

my eyes any further unless I become a

cyclops and then moving it back out

again and doing that for you know 10 to

25 repetitions maybe once or twice a day

a few times a week that's what those are

pencil push-ups yeah yeah so

um you're certainly not going to hurt

anything there are other situations

where those really do get prescribed and

there's definitely some good clinical

trial data suggesting that they can

actually help for example recovery from

concussion a lot of people actually

one of the really telling ways to

diagnose concussion and this can be

concussion from sports or a fall or you

know any any source of concussion your

smooth Pursuit which is the ability

let's say I've got a DOT moving around

in a circle on a screen and I'm

following that thought with my eyes my

eyes should be able to very smoothly

follow that circle around

watching a hockey game is that like your

body fan right like that you know just

following a ball you know following any

movement with smooth Pursuits of your

eyes

and after concussion that actually those

systems in our brain the sort of

reflexive ability to properly follow

that use that visual input to tell your

eye muscles exactly where to move

gets disrupted and so all of a sudden

your smooth Pursuit starts to look

choppy it's not so smooth anymore and

it's actually a way to diagnose and

follow recovery from concussion and part

of the visual rehab sort of neuro rehab

one of the approaches being used and

further studied still in recovery from

concussion is actually doing those kinds

of exercises like pencil push-ups or

basically what you've described is

focusing from far away to focusing near

and doing that back and forth and using

that to sort of like help regain uh the

tighter control of our eye movements and

that eye brain connection so if

traumatic brain injury causes deficits

in smooth Pursuit eye movements and some

of the recovery protocols for traumatic

brain injury are to have people do

smooth Pursuit protocols and pencil

push-ups are these also the sorts of

things that anyone can just do I mean

whenever possible we like to share tools

for various aspects of Health on this

podcast but of course we don't want

people cowboying this stuff in a way

that could be detrimental to their to

their Vision so is it okay to get on

YouTube and find a smooth Pursuit um

Tool uh we can put a link to these there

there are several of them

um and people spend a few minutes doing

this yeah

you're definitely not going to hurt

anything so totally fine to do it and

some people may notice you know like

they feel a little more visually active

if they do these kinds of exercises

um I think most people would do them and

not notice something in their daily life

we actually have

um

made so much progress you know in

research in thinking about how do we

take the diseased or dysfunctioning or

aging eye and get it back to healthy and

normal

but there's a whole other area of

science that's we're really just barely

touching we've actually we've actually

just opened a vision performance center

to really get at not just how do we

rehab the sick eye back to health but

what's the difference between

functioning normally and functioning

above normally

for example athletes when they get

studied for visual Vision

characteristics they have faster visual

reflexes higher visual Acuity uh how

much of that was you know genetic how

much of that is trained we don't really

understand could we train all of us with

you know normal vision to get up to

Supra normal vision these are like great

important questions that are really

relevant to you know every regular

person of course you know people doing

Esports and the gaming communities and

athletes is part of what we're studying

in the vision performance center but

these are really really big

opportunities to try to understand how

do we move people from normal vision to

Super normal vision and there's evidence

that you can do it so here's a great

example some athletes train

using these special goggles that

actually use electrical signals in the

glasses part of the goggles to actually

black out your vision one thirtieth of

every second two thirtieths of every

second three thirtieths of every second

now imagine you and I are passing a

basketball back and forth except you're

wearing goggles and all of a sudden

you're only getting 90 percent of the

data of where's that basketball on its

way to my hands now you're only getting

eighty percent now you're only getting

70 percent of that visual information

and you are practicing right you are

getting good at catching a basketball

when you only have a fraction of the

visual information and now I put you

back on the basketball court without the

goggles you might be really good at

passing that basketball around and

catching that basketball right and so

the idea that we could train and

understand the biology of training to

get the eyes from normal to supernormal

Performance I think it's an amazing area

and one that we've really just started

to dig into that's fantastic so this is

a a new program at Stanford through the

department of Ophthalmology is it linked

up at all with the woosai performance

Institute yeah actually there's been a

lot of focus over the years I think in

human performance and there's actually a

new human performance uh Alliance and

Center we've we've we've long had really

run through the department of our

Orthopedics a human performance

laboratory that's really you know much

more about joints and muscles and

strength and conditioning and stretching

to layer on to that now a real

understanding of how vision is operating

you know it's interesting let's go back

to the example of concussion you know

we've got I don't know about 800 Varsity

student athletes and all the different

sports at Stanford and you might have a

student athlete come in and say you know

something doesn't feel right I got a

little hit on the head I feel like my

vision is a little bit messed up maybe

I've got a mild concussion you could

imagine doing some of these tests on

some of these performance athletes for

example and saying well gosh you look

normal

but actually they used to be operating

at a supernormal rate and this is a

noticeable decrement for them and so

just starting to study and understand

what's the difference between normal and

supernormal how do we go back and forth

between those two how do we measure that

difference and maybe ultimately how do

we train into that difference I think

it's going to be exciting and not just

for athletes you know for for regular

people you know you talk about driving

at night is there a solution where we

could train our eyes to be better at

driving at night and I don't know maybe

reduce the number of accidents that

happen out in the world so well

certainly there's

um physical training protocols which are

redefining what a 60 year old or 70 year

old

could look like and feel like and be

able to perform like why not do the same

for vision

um so I don't think there's anything

Supernatural or greedy about doing it I

think that's the excitement of biology

and neuroplasticity that you can extend

it forward as opposed to just trying to

wire up correctly during development

this is a perfect time for me to ask you

a question that I'd love a clear answer

on if it's possible it's not always

possible which is

could you define 2020 vision and a few

of the variants so that any person could

understand it so we think of 2020 as

perfect vision what does that mean what

would degraded Vision look like

whatever those numbers are and then what

would above normal super normal vision

look like yeah and is it true that

fighter pilots have Supra normal vision

yeah that's another population like like

like many athletes of of people who may

have sort of better than normal vision

2020 you know we Define almost

everything we do based on you know kind

of a average not sick human being adult

whatever it is right and so 2020 Vision

means that you can read the smallest

letters at 20 feet away that the average

healthy person can read

at 20 feet away so you can read at 20

what they can read at 20. okay now if

you have worse than 20 20 Vision maybe

you have 20 25 Vision 2040 Vision maybe

you have 2200 Vision which on the eye

chart at the office is like the Big E at

the very top is 2200 Vision that means

you can read at 20 feet what a normal

person could read at 200 feet right so

you've got pretty limited lower Vision

we can measure down to like 2400 2800 at

that point we're getting into like gosh

can you count how many fingers I'm

holding up you know that kind of thing

and then ultimately hand motion can you

even tell if my hand is moving in this

side of your vision or this side of your

vision

and then ultimately after that light

perception can you tell if the room

lights are on or off right and that's

kind of the edge of of being actually

fully blind we call Legal blindness in

the United States typically 2200 or

worse and is it true that there are

people who are legally blind that are

out there driving as we're having this

conversation I I have to imagine that

that is unfortunately the case but it

shouldn't be because those people

obviously are really severely impaired

and and that's obviously quite dangerous

so so so that's 20 20. now

it gets worse 2040 2080 20 100 can it

get better yeah it turns out that people

can be sort of on the other end of that

curve and so we could have athletes and

fighter pilots or people who have had

LASIK surgery who are 2015

2010. if you're 2010 that means you can

see it 20 feet what the average person

needs to be only 10 feet away to see

right and so you've got better than

normal vision and people do get to that

through a variety of ways and so it is

possible to have better than 20 20

vision

does the degree of visual Acuity because

that's really what we're talking about

here differ dramatically between the two

eyes

in most healthy people know

um you know remember we talked about

you're born with something like 2200

Vision takes you a couple of years and

it can be a little bit asymmetric 2200

Vision yeah that reminds me um I've seen

images of what babies can see you know

parents love looking at their child and

thinking their child is looking right

back at them and indeed often the child

is looking right back at them and your

face to your child sorry to break this

to you folks is incredibly blurry even

at that close distance for probably the

first six to eight months events before

you come into sharp relief they're not

seeing the fine details of your face

yeah so smile big that's right smile

break keep those eyebrows dark right and

keep cooing at them because they can

hear pretty well that's right yeah the

Optics of newborn babies are just

dreadfully bad yeah but they need

visuals now other species not you know

Hawks

Raptors owls that hunt uh they can

naturally have 2010 28 Vision right so

much better vision and that's just their

normal vision as best as has been

measured so so there's definitely the

potential for us to have better than 20

20 Vision now all of this we call Visual

Acuity and just to be clear for everyone

that's the vision in the very center of

your vision like when you're reading or

looking that's the very center of your

vision

our vision is actually described

variably as a hill of vision the peak is

in the center that's let's say 2020 in

most people right but it's it's normal

to have that slope off and our visual

Acuity your ability to read the eye

chart on the edges of your vision if you

can read the Big E that's pretty normal

like you would be 2200 out on the edges

of your vision and we would feel like

yep that's pretty normal

um so so our highest Acuity Visions in

the center and that's a big part of why

we spend a lot of time using those eye

muscles to look around right we gotta we

gotta get a little bit of a high Acuity

view of what's around us uh fill in fill

in the gaps of what our what our brain

is is interpreting our peripheral world

to look like it's almost like we have

two visual systems we have a high Acuity

High pixel density camera in the middle

and then surrounding that is a pretty

low resolution but very fast detector

camera yes yeah yeah you mentioned Lasik

but I want to make sure that before we

talk about Lasik that we talk a little

bit about contact lenses is there any

detriment to having a piece of glass or

a piece of plastic on the front of your

eye all the time and the reason I ask is

not because I think we should live

necessarily exactly like our ancestors

but it's a pretty bizarre adaptation

to put a lens directly onto the front of

the eye you have to imagine that the

cells and tissues there are accustomed

to getting a certain amount of oxygen

they're accustomed to get a certain

amount of interaction with the

environment and and you also are now

adding another surface the way that the

tears are going to interact with the

um you know with the cornea of the eye

are probably changed and who knows maybe

it doesn't make any negative difference

at all but you know putting a contact

lens on the front of the eye is you know

about as close to putting a device on

your brain as I can think of except for

maybe the cochlear uh implant yeah yeah

that's a great question now first of all

um I want to distinguish uh there are a

few really medical uses for different

kinds of contact lenses like scleral

contact lenses for people of certain

diseases there are other kinds but I

think what we really want to talk about

right now is just kind of the

run-of-the-mill I want to get my

prescription taken care of but instead

of wearing glasses I'm going to wear

contacts

contacts even the newest generation

contacts yes they sort of uh change the

tier Dynamics on the surface of your eye

they

um they decrease the oxygen you know

diffusion that's just sort of out in the

air onto the surface of our eye onto the

cells that are on the surface of our eye

but most of us especially as we're

younger have enough tear film Reserve

enough oxygen Reserve that we can easily

tolerate these polymer gel soft contact

lenses and and wear them happily the

advantage of contact lenses over glasses

purely from the perspective of

correcting your vision is that there's

different elements of of of of of the

shape of your eye that need to be

corrected if you need corrective lenses

and so for example if you're for the

basketball shape of your eye is a little

too steep or a little too shallow that's

what the standard glasses correct you

may have been told that you have

something called astigmatism that's

where instead of having a basketball

shaped eye you have a slightly football

shaped die it's not round in the same

dimensions on both axes and again

glasses can correct that but then

there's higher order aberrations in our

corneas in the clear window in the front

of our eyes or or to some degree in the

lens inside the eye that are that are

focusing the light that the glasses

prescription can't correct but if you

have a nice smooth contact lens on the

front it can correct so a lot of people

who wear glasses and contacts will

report that they have a much higher

quality of vision with their contact

lens correction than with their glasses

correction and again in service of

enjoying the best Vision that you can

enjoy in your daily life that's an

upside to seeing if contacts could work

Frio now there's another element though

and that's like gosh is there a risk of

contact lenses and especially as we age

um we have less tear film reserves so

contacts may become less tolerable as we

age

and the other thing is being really good

about the cleaning because you know the

contacts can trap bacteria or fungus and

if you get a corneal infection from a

contact lens it actually can be quite

devastating to your cornea even if you

successfully treat the infection you can

be left with some corneal scarring

thankfully this happens very rarely but

when it does happen it can be quite

difficult on you know on the person

thereafter to sort of suffer through

having maybe a scar from that infection

on the surface of their cornea that they

that leads to some blurring vision for

example so we always recommend that if

you're going to wear contacts that you'd

be really attentive to whether you're

tolerating them well

and then also to be really attentive to

the recommended use and cleaning of the

contact lenses I actually recommend that

even though they're a little more

expensive to afford that people should

almost always be just using the daily

contact lenses that they don't have to

clean or use for you know two weeks or

four week period so these are disposable

contacts highly disposable and I hate to

think of you know I don't know filling

our oceans or what have you with uh more

more more polymer plastic but at least

the contact lenses are small and it's

much safer for your eye to use a daily

disposable than to use a two week or a

four week and be responsible for the

cleaning the other thing to be really

responsible about is sleeping in them

overnight because overnight when your

eyelids are closed of course now you're

getting even less oxygen to the surface

of your eye actually most bacteria

especially many of the Infectious

bacteria to our bodies and to the

surface of our eye are actually bacteria

that Don don't really like oxygen and so

we've got a low risk of getting

bacterial infections on the surface of

our eye but if we use contacts too much

don't clean them or sleep in them

overnight when our eyelids are closed

and now there's even less oxygen kind of

helping keep the surface more more clean

if you will that increases the risk a

lot so being really good with the

recommended use and cleaning of the

contacts is critical considering daily

use contacts you don't have to and look

most contacts are going to be the two

week or four-week kind where you put

them in the cleaning solution overnight

each time give them a good rinse and put

them back in the next day and again most

people 99.99 some percent of people are

going to do just fine with that follow

the instructions and never get into

trouble

as we age they're going to become less

tolerable people are going to say I used

to wear my contacts for 12 hours now my

eyes feel really dry after six or eight

or ten hours

maybe some years after that they say

gosh I could barely use it for four

hours I only use them when I go out on a

Saturday night uh and and that's okay

you can you can you can back off as you

need to back off but in the meantime if

it helps you especially in the younger

decades if it helps you really enjoy uh

Your Best Vision great

what about UV protection in eyeglass

lenses and or contacts

I've dealt with many questions about

blue light I am not somebody who

believes that all blue light is terrible

I think it's important to avoid Bright

Lights of any wavelength late at night

if you want your melatonin production to

be normal and you want to sleep well it

doesn't matter if you're wearing blue

blockers or not if you're just under

blastingly Bright Lights it's going to

suppress your melatonin and yet some

people enjoy blue blockers for that

reason nowadays A lot of people wear

blue blocker

glasses or blue blocking lenses or

contacts throughout the entire day

thinking that blue light is bad for our

eyes during the day I happen to

subscribe to the idea that we want as

much bright light as we safely can

tolerate during the day ideally from

sunlight

in order to set our circadian rhythm and

yet a lot of eyeglasses and a lot of

contact lenses out there have UV a and

or UVB blocking features to them so what

are your thoughts on this and I'm

perfectly happy to be wrong and revise

my my stance on this

um yeah what what do you think about

this UV a B blocking yeah it's a good

it's it's a it's really important to

distinguish that UV light on the light

spectrum is right next to blue light red

lights on the other end and of course

infrared is beyond that and our eyes

other animals can see these but our eyes

can't see infrared that's why we call it

Beyond red and we can't see ultraviolet

we call it Beyond violet UV light is

right next to Blue Light UV light is

known to have a lot of adverse effects

it's not really good for our skin and

therefore you know we really want to

avoid Sunburn and kind of UV data you

know exposure and damage on our skin

similarly it's not really good on our

eyes and it affects both the ocular

surface a little bit in terms of like

kind of how dry or irritable your eyes

might feel for some people and certainly

over the long term UV light will

accelerate the formation of cataract

which is a blurring of an oxidative

blurring of the lens inside the eye

profound UV light can be damaging to the

retina if you're getting way too much on

the inside

so uh so blocking UV light I believe is

just absolutely standard in every pair

of eyeglasses and I don't know actually

how much to what degree the different

kinds of contact lenses also filter at

least UV light now blue blockers blue

blocking glasses is totally different

and

as I say like I think almost all glasses

because the Plastics almost all glasses

are not made of glass anymore they're

made of plastics but I think almost all

of them now filter the UV light which

again is like probably the safe move for

our eyes and periocular environment

around the eye environment

so blue blockers you know that's been a

huge fan I'll tell you the last three

years through the pandemic everybody

getting on their computer hours in front

of Zoom meetings where we used to walk

from building to building for a meeting

things like that

um I you know I I remember you know like

this sort of big uptick in these kinds

of questions and I'm not sure that

there's any data that blocking blue is

helpful in any way and as you say it may

actually play into sort of circadian

entrainment of our natural daily Rhythm

so so I think blocking UV is a good idea

and I think it's pretty standard you

know they make glasses is by the way

that actually react to UV light they're

called transitions there may be a few

different brands I don't know uh but but

you know these are the sunglasses that

are clear except then they turn dark if

you're out in the sunlight and it's not

just any sunlight it's actually the UV

wavelengths that that cause the chemical

reaction in the glasses to turn from

from Clear see-through to to sunglass

blocked glasses

and um

you may notice if you if any of you out

there are using these kinds of glasses

uh that they don't work in the car

you'll wear them in the car and they

won't go to sunglasses even though it's

sunny out and again that's because all

standard car glass also filters UV

that's why if you're riding around in

the car and it's sunny out you've got

your hand you know up next to the window

uh wearing a t-shirt you never get a

sunburn through the car window anymore

because all our car glasses also

filtering UV light for us so so that's a

very informative answer and before we

started recording you and I were

discussing this practice of morning

sunlight viewing which again I highly

recommend over and over and you pointed

out that low solar angle sunlight so

sunlight low in the sky viewed for maybe

10 minutes a morning and again not

forcing oneself to look at it and stare

but blinking as needed is not going to

cause extensive UV damage to the eyes

it's really the when the sun is directly

overhead that we're getting a lot of UV

which raises this other question which

is for people that don't wear corrective

lenses and therefore are not blocking UV

light to the eyes

um what should they do are they in

trouble should they be wearing a brimmed

hat brimmed Hat's a great idea that I've

got a rid of a lot of the direct light

into the eye of course you still have

reflected light off of surfaces and that

that can include UV light of course

um you know wearing sunglasses outside

even if you don't have corrective lenses

you know it's may also be more

comfortable to wear sunglasses outside

um so so these are all fine you know

at the end of the day it's probably not

making a huge difference in the health

of your eye whether you've spent the

last 50 years wearing sunglasses really

dogmatically for your outdoor time or

not you know if you were going to

develop let's just say age-related

cataracts inside your eyes which

we'll all get if we all live to 120 we

all get cataracts you know it's going to

happen some people younger some people

older maybe if you were really dogmatic

about wearing your UV blocking

sunglasses maybe you'd get your your

cataracts at 75 years old instead of 72

years old it may not be a huge

difference in that regard so again not

something to be super stressed I think

it's I think it's more a question of

just what are you comfortable in uh and

then certainly I will say the the other

advantage of a wide brim hat is it's

keeping sun off of your face and these

are the you know some of the especially

the upturned portions of your face like

the cheeks and the nose these are the

some of the most common places to get

some of the skin cancers that you can

get over a lifetime of sunlight exposure

so you know the wide brain app is it's

helping you for that as well

can't help but ask about comfort

at varying levels of brightness I'm the

person that when sitting in a cafe or

something and on a bright day I can be

directly across from somebody like you

who seems to be perfectly fine without

sunglasses and maybe even more shaded

under an umbrella or something of that

sort and I'm squinting like crazy

is it normal for there to be a pretty

wide variation in sensitivity to light

and does this have anything to do with

the lightness or darkness of the eyes

you have brown eyes I have green eyes

but is there any real correlation there

yeah you know it's a good question I

don't know if it's been formally studied

but I will tell you like I have the same

impression you do which is that if you

have uh blue eyes or light-colored eyes

that you're more likely to have more

sensitivity we know that there's

differences in the iris muscles that

constrict and dilate in response to

light

for example when you go into your eye

care provider and they're going to do a

dilated exam and they put the eye drops

in your eye that dilate the eyes they

sort of change the the nerve impulses

onto the iris muscles of the iris

dilates and you get those big big open

eyes

um people with blue eyes we absolutely

know blue or Hazel or light colored eyes

uh you put that eye drop to dilate there

rise it's going to last four six eight

hours whereas in a brown-eyed person

often the dilation only lasts one two

four hours so there's clearly biological

differences between the irises and their

muscles and maybe the nerves that feed

those muscles uh between light-eyed

people and and darker eyed people and

that may also therefore relate to this

differential sensitivity that some

people have you know if you're not able

to constrict your eyes in the bright

light as effectively you're going to

find that bright light more frustrating

more annoying uh you know even painful

people will feel like their eyes are

cramping almost as they try to get that

those eye muscles to activate to bring

down the pupil and block some of that

excess light from getting in interesting

yeah let's go back to Lasik what is

LASIK and

should I get Lasik eye surgery does it

does everyone need Lasik can it help

every can it make us you know

suprophysiological you know can it make

me a 2010. you know often it can I'll

just say that you know right up front it

is amazing people will come out of Lasik

surgery uh better than 2020 but uh the

cornea we talked about before that's the

Clear Window on the front of your eye

all the light has to get through there

and we talked about before already like

if your cornea is misshapen if the

basketball shape of it is too too

shallow or too steep then you're going

to need glasses to see a distance and

also at near if it's to football instead

of basketball then it's going to be what

we call astigmatism and uh and then you

can't you need a correction for that

instead of correcting with glasses that

sort of help shape the light so it can

go through your slightly off-shaped

cornea instead of wearing contact lenses

which also shape the light just as it's

entering your cornea right on the

surface of the eye you can just reshape

the cornea

and the way Lasik does that there's a

few different versions of Lasik but

basically the way the Lasik does that is

it actually ablates or uh gets rid of a

little ring or rim of that corneal

tissue

so that for example if you were a little

shallow and you got rid of a little bit

of that tissue around the edge with the

laser the Lasik you know starts with the

word laser if you got rid of that edge

tissue then you're sort of making it a

little more basketball shaped right or

if you were too steep on your cornea and