0:01

Before we get to the show, we've got an exciting announcement.

0:04

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0:08

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0:16

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Live, and you can find a link in the show notes

0:26

for our August 30th episode.

0:31

Sarah Zane has pretty much been wearing

0:33

glasses her entire life. My

0:35

eyesight is quite bad, and it's actually something

0:38

that caused my parents and then sort

0:40

of me a lot of anxiety

0:42

when I was younger.

0:43

So much that her parents actually tried to fix

0:46

her eyes. When I was growing up, my mom

0:48

would make me do these eye exercises

0:50

where you kind of like rub your temples or

0:52

your brows and like move your eyes around. But

0:55

there's research now to say that these exercises do

0:57

not work.

0:57

But Sarah isn't too worried

0:59

about wearing glasses these days, especially

1:02

because almost everyone she knows wears them

1:04

too.

1:05

When I see someone who's not wearing glasses, I assume they're

1:07

wearing contacts now, and I'm almost always

1:09

right. She started wondering, is

1:11

this normal? Is it weird

1:14

that everyone she knows has bad

1:16

eyesight? When I talk to eye doctors and

1:18

ask them about this, they're like, oh yeah, it's going up. We're

1:20

seeing so many more kids. We're seeing kids coming

1:22

in younger. So Sarah

1:24

started digging into the research, talking

1:26

to scientists, and she wrote up

1:28

what she found in a piece for The Atlantic. Turns

1:30

out her hunch that more people's eyesight is getting

1:33

worse?

1:34

It's true.

1:37

In the past, like, you know, 70 years or so, people

1:39

have been noticing that there's been an uptick in myopia.

1:42

Myopia is just another word for nearsightedness,

1:45

when you can't see things that clearly if they're far

1:47

away. And more and more

1:50

people are becoming myopic.

1:52

It's happened kind of most dramatically

1:55

in Asia, where almost 90%

1:58

of teenagers need glasses.

1:59

So that's like nearly almost everyone,

2:02

right? But it's not just Asia.

2:04

Eye sight's getting worse all over the world, including

2:07

in the U.S. The sort of most recent numbers

2:09

are from the 2000s, which is about 42% of

2:11

adults are near sighted, and

2:14

that's from a quarter of the 1970s.

2:16

This isn't just making it harder to see.

2:19

Myopia can come with long-term risks.

2:22

In 50 or 60 years from now, you might

2:24

have people who were myopic all

2:26

their lives, and now they're kind of developing these really

2:28

serious eye conditions that could actually lead to blindness.

2:30

A hundred years ago, this kind of thing

2:32

was really rare. So

2:35

what changed? Why is all this myopia

2:37

happening now?

2:38

Something about the way we are living

2:41

our modern lives, we think that is causing the myopia

2:43

that we are now seeing everywhere. We are

2:45

doing something to our eyes that is bad, but

2:47

we can't pinpoint exactly what it

2:50

is.

2:52

I'm Noam Hasenfeld, and this week on Unexplainable,

2:54

what's ruining our ability to

2:57

see? And is there anything we can

2:59

do about it?

3:16

So Sarah, before we get to some

3:18

of the changes of what's happening here, what

3:21

makes someone near sighted or far

3:24

sighted to begin with? How does that work

3:26

in the eye? So an eyeball is usually

3:29

kind of a round shape. When you're far sighted,

3:31

your eyeball is too short. When you're

3:33

near sighted, your eyeball is a little bit too long.

3:35

So it's kind of more shaped like an olive. And

3:37

the back of that eye can get quite

3:39

thin if you think about taking a balloon

3:42

and kind of stretching it or squashing

3:44

it. Like that's kind of what's happening to an

3:46

eyeball when it's not the right shape.

3:49

And what's interesting is that we are actually all

3:51

born far sighted as babies. We're not born

3:54

with perfect vision. Babies are all far sighted.

3:56

Our eyeballs are a little bit too short. And over the

3:58

course of our lives.

3:59

as our eye gets these signals from the environment,

4:02

it grows the right length so that we

4:04

have perfectly clear vision. But our eyeballs

4:07

are just growing a little bit too long.

4:10

Isn't myopia something you either have or don't

4:12

have? Like

4:14

both my parents are nearsighted, my brothers

4:16

and I are nearsighted. Like is this

4:19

theory

4:20

contentious at all that myopia is going

4:22

up? So originally if you even go back

4:24

like 30 years, it actually was pretty contentious.

4:27

Some scientists or doctors were actually pretty

4:29

down on the idea that myopia could be growing up so fast.

4:31

Because traditionally what we learned is that myopia

4:34

is inherited. So if you have

4:36

parents who are nearsighted, you're more likely to be

4:38

nearsighted. If you have siblings that are nearsighted, you're

4:40

more likely to be nearsighted. But the idea

4:43

is that it's genetic. So in that

4:45

case, the rate in myopia

4:47

should pretty much be level across

4:49

time. But now we're seeing this increase,

4:52

not just in Asia, but also through

4:54

a lot of the developed world. And I think it's just

4:56

like, it's so big that it's like

4:59

clearly it's not genetics, right? Like so

5:01

many more kids are myopic than when

5:03

compared to their parents, someone compared to their grandparents.

5:06

This is like not a matter of genetics. So

5:08

now it's no longer controversial that this is

5:10

happening. But why it's happening

5:12

is still controversial.

5:14

What are some theories? Well,

5:16

there's like a really intuitive theory, right? Which is

5:18

that like, hey, we're just staring at our phones

5:21

and our screens and our TVs all the time. Obviously

5:23

that's what's going on.

5:25

And even like a hundred years ago, before

5:28

we had electronics, you had people saying,

5:30

hey, it's like all these people spending time on their

5:32

books all the time, you know? But

5:35

it's only become sort of so ubiquitous

5:37

in sort of the past several decades. I read

5:40

studies from I think the 1960s, 1970s of

5:43

eye doctors going up to Alaska, as

5:45

far north in Alaska as you can go in this really

5:47

remote areas where they'd

5:49

found that there had been this huge uptick in myopia

5:52

in the indigenous population there. And

5:54

that's because like schools had

5:55

opened there. So, you know, the population

5:58

had like started changing. traditional

6:00

ways of life and kids are going to school every day and

6:02

their grandparents did not need glasses, their parents

6:05

did not need glasses, suddenly these kids started

6:07

needing glasses. Wow. And

6:09

in Orthodox Jewish communities, there's

6:11

actually a really high level of nearsightedness, but

6:13

only among the boys, not among the girls. And that's

6:15

because the boys are the ones who are spending

6:18

a lot of time doing their studies and

6:20

reading their books. So there's a pretty

6:23

clear environmental cause

6:25

here, right? And to kind of traffic and

6:27

broad high school stereotypes, all the nerds are wearing glasses,

6:29

the jocks are not. I actually

6:32

grew up Orthodox Jewish and I spent a year in a

6:34

seminary in Jerusalem and was studying

6:37

a lot of Talmud very close to my face

6:39

and my eyes got really bad.

6:41

Oh, well, there we go. Just

6:43

anecdotal. You proved it. Yeah.

6:46

Were your classmates, were they wearing glasses? Everyone's

6:49

got glasses.

6:52

So just so I can understand the mechanics here,

6:54

is the idea that if we are focusing on a lot

6:57

of stuff near to our eyes, our

6:59

eyes are

7:01

becoming attuned to only that space?

7:04

Yes, exactly. So it's a little bit like

7:06

if you don't use it, you lose it. Basically by

7:08

looking at things in front of your face all the time, you're

7:10

telling your eye, oh, only the things right

7:13

in front of me are important to focus on. These things are

7:15

far away. It doesn't really matter. And so

7:17

then maybe under this

7:19

theory, your eye then grows to say,

7:21

okay, I'm only going to focus on things that are near

7:23

to me. The problem with this theory, which

7:26

feels very obvious and very intuitive, is that if

7:29

you go out and do the research

7:31

and you track the number of hours

7:33

kids are spending on what researchers

7:35

call near work, which is reading on your

7:38

phone, anything that's close to you, if you

7:40

look at the number of hours kids are spending

7:42

on near work, there actually isn't much of a correlation

7:45

between that and how bad their eyesight

7:47

is in terms of distance vision, which is

7:49

very puzzling. Sometimes a study will find a

7:51

correlation, but then another study will not.

7:54

So if it's not spending time reading

7:56

on our phones, what else

7:58

could be going on here?

7:59

One more theory is that like, oh, actually, we are

8:02

going about this backwards. It's not the amount of time

8:04

you were spent looking at things close to you indoors.

8:07

It's the amount of time you are not spending outdoors

8:10

as the problem. And we don't know exactly

8:12

why, but there are a couple of theories that

8:14

have been floated. One is that simply

8:16

it's a lot brighter outside. And something about that

8:19

really bright sunlight gives signals so the eyes

8:21

are protective in the way that being indoors is not.

8:24

And just by example, you know, like, lux

8:26

is usually like how we measure how

8:28

bright light is.

8:29

That's like L-U-X? Yes, L-U-X.

8:32

And so indoors, it might be like 1,000 lux. Outdoors

8:36

on a sunny day, 100,000 x. Even

8:39

a snowy day, 20,000 lux. So

8:41

this is like a really huge difference in how bright it is

8:43

indoors and outdoors. And so there's some scientists

8:46

think it's because there's something in that sunlight

8:48

that is protective. Because again, we're used to being

8:50

outside in the sunlight. Makes sense. Another theory

8:52

holds is that it's not really about how bright

8:55

it is. It's really about the fact that when you're

8:57

outdoors, you're looking at things far away, as

8:59

we were talking about earlier.

9:00

Right. That seems also intuitive. Yeah. So we

9:02

don't, you know, there's no agreement on exactly

9:04

which part of being outdoors is protective. But

9:07

there are many who argue that it's not about

9:09

the fact that you're spending too much time on

9:11

your work. It's the fact that when you're doing your

9:13

work, you're not

9:14

going outside and being exposed to whatever protective

9:17

effects there are. So is

9:20

there

9:20

evidence on either? How do we evaluate

9:23

these hypotheses?

9:24

I think the question of, like, is it the brightness

9:26

or is it something else going outdoors, I think

9:28

that's pretty hard to disentangle because you

9:31

generally have both when you're outdoors. I

9:34

remember having one conversation with a scientist.

9:36

And I just kept asking her a question about, like,

9:38

why are people myopic? How does the eye work? And

9:40

then she was like, OK, here's not the controversial

9:43

point. And then she was like, no, this part is also controversial. She

9:45

was like, no, this part is also controversial. She said this probably

9:47

like five or six times over the course of our conversation.

9:49

I was like, I thought I was just asking basic questions

9:52

about how the eye works. Like, why is everything

9:54

so up for controversy? But

9:57

I think the thing is just that, like, you know, it's

9:59

pretty. It's pretty hard to answer

10:01

questions in science sometimes. I think what's

10:03

also difficult is that a lot of the experiments

10:05

to kind of understand how the eye grows, they

10:08

have been done in lab animals and like under

10:10

very specific lab conditions. So often

10:12

chicks, sometimes monkeys, sometimes rat

10:14

shrews. And then you can go and like

10:16

dissect the eye. You can go in and like do

10:19

like very controlled things that you never

10:21

do in a human. Like put a kind

10:23

of like little glass bubble over one eye

10:25

and then see how the eye grows. And actually what happens

10:28

is the eye becomes myopic because it's like not getting

10:29

the right signals from the environment. So in

10:32

lab animals, we can do this with kind of like a

10:34

lot of specificity, but kind of under like really weird

10:36

artificial conditions. Right, it wouldn't

10:38

be

10:38

that much fun. Right, yeah. And maybe

10:41

your vision might be semi-permanly

10:43

messed up. I don't think I would agree to that. Yeah,

10:45

I'm not agreeing either. So

10:48

I think there's a little bit of a gap between

10:50

like what we can observe in animal studies and

10:52

like what we can then extrapolate

10:54

to is happening in human eyes.

10:56

So ultimately if we don't know

10:58

the exact cause here, is

11:01

there anything we can do? Can we stop

11:03

this at all? So I don't know that

11:05

there's like a very clear answer to exactly

11:07

what is going on, but we also don't need a very

11:10

clear answer to try to do something about

11:12

it.

11:14

So

11:14

I think like regardless of what the sort

11:16

of exact biophysical cause

11:18

is, like we know we should probably be spending

11:21

a little bit less time on our phones and a little bit more outdoors.

11:23

On the other hand, there aren't these like new

11:26

crop of treatments that are supposed to slow

11:28

myopia and understanding

11:30

like what is going on with myopic eyes can

11:32

help us understand why those treatments seem to work and

11:35

maybe try to develop better ones.

11:42

What we might be able to do about the rise of

11:44

bad eyes after the break.

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12:24

my

12:27

eyes!

12:28

I can see clearly now

12:31

the rain is gone.

12:34

So over the last few decades, people's eyesight

12:36

has been getting worse. It might be because of staring

12:38

at screens. It might be because we're

12:40

not spending that much time outdoors. Scientists

12:43

aren't sure. But

12:44

the question is, what can we do about

12:46

it?

12:47

The most obvious thing might just be getting

12:49

glasses or LASIK, laser

12:51

eye surgery. But Sarah says

12:54

these interventions don't actually fix

12:56

myopia.

12:57

The thing is that LASIK and glasses

13:00

and contacts, they don't correct what is

13:02

the underlying anatomical problem of myopia.

13:05

The problem with myopia is not just that you can't

13:07

see that well, it's that your eyeball

13:09

is the wrong shape. So LASIK doesn't

13:11

really change the shape of your eyeball. What it does

13:14

is it kind of changes the little

13:16

clear part in front of your eye, the cornea, it kind

13:18

of changes that shape of that little clear

13:21

part in front, but doesn't change the length of your

13:23

eyeball. So you can get

13:25

LASIK, you can see well, but all those

13:27

high risks of things like a coma

13:29

or retinal detachment, those still apply because

13:32

your eyeball is still too long.

13:34

So once the eye does stretch,

13:37

whether it's from looking at screens

13:39

or doing math problems or not going outside,

13:42

is this something we can undo?

13:44

No, we can't. Once the eye gets too long, you

13:47

cannot reverse it. So this is why

13:49

eye doctors now are kind of really

13:52

interested in these new treatments

13:54

that are called myopia control or sometimes called

13:56

myopia management. So they can't

13:58

reverse what's already happening.

13:59

But what they really can do is

14:02

they can make it go a little bit slower.

14:04

So how do these treatments

14:07

work exactly? So there's three

14:09

different types of myopia control basically.

14:12

It's an eye drop or special contact

14:14

lenses or another set

14:16

of special contact lenses called ortho K.

14:18

So the eye drops are a chemical

14:20

called atropine. They're actually been used

14:23

a lot in eye medicine in

14:25

the past to dilate your eyes at higher doses

14:27

that kind of make your pupils look bigger. At

14:30

really, really low doses, like at like 1,

14:33

100th of what a typical dose would

14:35

be, using these atropine eye drops

14:37

seems to slow

14:38

the progression of myopia in

14:40

kids. And it's not really clear

14:42

exactly what is going on, but the theory

14:44

is that it somehow interferes with the

14:47

chemical signals in the eye, and it's preventing

14:49

the eye from growing too long.

14:51

So that's the eye drops that are kind of slowing the

14:53

progression of myopia. Yeah, you know, it's

14:55

like the difference between being like nearly

14:57

blind to like being able to sort of see without your glasses.

15:00

The contact lenses kind of are about

15:02

similarly effective and there are two different kinds.

15:05

One is called ortho karatology or ortho

15:08

K. And again, this is an existing treatment

15:10

that's already on the market, has been

15:13

used for years and years and years. And what these are, these

15:15

are hard contact lenses that you wear at night.

15:18

And it kind of reshapes the cornea of your

15:20

eyes, sort of like the clear outer part of your eye, so

15:23

that you can have perfect

15:24

vision during the day. So you don't have to wear anything

15:26

during the day, which like athletes really like to do. Wow.

15:30

That's like a retainer for your eyes or something. Yeah,

15:32

but it only sort of lasts like about

15:34

like the eight hours during the day. So you have to do

15:36

this every day. Otherwise, your

15:39

eyes will go back to normal. This is like a very

15:41

temporary thing, unfortunately. It's not

15:43

a permanent fix. You have to do it every day. The

15:47

others, the third treatment are

15:50

soft contact lenses, but the multifocal contact

15:52

lenses. And so what they do,

15:55

and actually what ortho K does is that they change

15:57

the way that light enters your

15:59

eye for your.

15:59

peripheral vision, right? So your central vision

16:02

is what you use to read, it's what you use to concentrate

16:04

on, which you focus on, and you need that

16:06

to be very clear. And so it kind of

16:08

gives you a prescription that you can see clearly when

16:10

you're looking at things at the center, but then it kind

16:12

of changes the way light enters

16:15

your peripheral eye. A lot of our researchers

16:17

suggest that it's your peripheral vision

16:19

that seems to really impact, whether you become

16:21

myopic or not, and sort of like changing

16:24

your peripheral vision and seems to be the key to slowing

16:26

myopious progression. So these

16:29

contact lenses sort of do this interesting thing, is where they

16:31

give you clear eyesight to

16:33

kind of correct your myopia right

16:36

now, but then also change your peripheral

16:38

vision to sort of prevent your myopia

16:40

from getting worse.

16:44

Okay. So how common

16:46

are these treatments? I mean, are they

16:49

accessible? They are

16:51

really common among certain

16:53

communities and now becoming more

16:56

mainstream. So it's actually

16:58

really common among certain Asian American

17:00

communities. There's a big clinic up in

17:02

Berkeley, California, where there are obviously

17:04

a lot of Asian Americans. And

17:06

that's because of the really high rates of myopia

17:09

in Asia itself. So actually, a lot of these treatments, the

17:11

original studies that were done, they were actually

17:13

done in Singapore or Taiwan. So

17:15

a lot of the studies, the research itself is coming out

17:17

of Asia, right? So these treatments are sort

17:19

of, they're building on things that existed

17:22

before, but a lot of the research to prove

17:24

that they're effective in kids, it's all coming

17:26

out of Asia. So it's just

17:28

sort of like the hotspot of the locust where this originated.

17:31

So just in terms of it diffusing

17:33

over here, it's just taking a little bit longer to get to the US.

17:36

I guess I'm wondering, if scientists were

17:38

able to figure out the precise cause

17:40

here, would that help

17:42

things? Would that, you know, enable us to act

17:45

differently or focus our interventions in the right

17:47

way? Yeah, I've also thought about this.

17:49

Like, if we knew exactly what was going

17:51

on, could we get more buy-in with

17:54

real behavioral interventions? Or

17:56

would we just end up with sort of maybe more

17:58

effective and more effective?

17:59

targeted, I guess, pharmaceutical interventions.

18:05

It's kind of funny. It's sort of the same way,

18:07

like, with obesity, you know, the

18:09

sort of like root society-wide cause

18:11

is that our lifestyle is a lot more sedentary

18:14

and we sort of eat a lot more high-calorie foods

18:16

than we used to. And

18:19

of course, the way we go about this are sort

18:21

of just like we buy Pelotons and we like

18:23

take diet drugs, right? Instead

18:25

of like sort of really changing our lifestyles,

18:27

because that would be so hard. Like we don't

18:29

want to go back to a Stone Age lifestyle. Like

18:32

we still want our modern lifestyles. So we've

18:34

like put this layer of technology on to kind

18:36

of allow us to keep living our modern

18:38

lives that when you zoom out

18:40

seems really bizarre. Like, oh, people are putting

18:43

like chemicals in their eye and they're putting like

18:45

little pieces of plastic in their eye

18:47

and they're kind of like changing the shape of their

18:49

eyeball. Like what? Like that's so bizarre.

18:52

But like, hey, that's the world we live in.

19:00

This episode was produced by me, Manning

19:03

Nguyen. There was editing from Brian

19:05

Resnick, sound design and mixing from Christian

19:07

Ayala, music from Noam Hassenfeld,

19:10

fact-checking from Serena Solon, and

19:12

tons of help from Meredith Hodnot, who manages

19:14

our team. Bird Pinkerton asked

19:17

the Doctopus what was going on.

19:19

The Doctopus whispered, her voice shaking.

19:22

It's the birds. I never

19:24

thought they'd find

19:27

us. So special thanks

19:29

to Maria Liu. If you have any thoughts about

19:31

this episode or ideas for the show, please

19:33

email us. We're

19:34

at unexplainable at vox.com. This

19:37

podcast and all of Vox is free, in

19:40

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off next week, but we'll be backing your feed on September

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19:53

Bye. you