
The myopia boom - signa11
http://www.nature.com/news/the-myopia-boom-1.17120
======
sithu
My wife is co-authoring a review paper on this topic with the group from
Zhongshan. The rise in myopia prevalence is really quite staggering,
especially among asians.

It's a long article, but the essential point is that insufficient time spent
in bright light >10k lux (roughly corresponding to being in shade on a bright
day) during early childhood increases the risk of developing myopia.

Normal eye growth requires dopamine which is released in a circadian fashion,
which requires exposure to bright/daylight. Absence of this dopamine cycle may
cause the eyeball to be more elongated, leading to refractive errors.

The precise number of hours needed to prevent myopia is difficult to say, but
studies in schools with even 40-mins extra have shown benefit, and there's
some evidence supporting 3+ hours/day.

Importantly, it doesn't seem to matter how much close-focal work kids do, such
as computer use/studying, as long as they spend sufficient time in bright
light. I'd consider setting up a study desk in front of a large window, and
taking breaks at school outdoors instead of inside.

~~~
benbreen
Would the rise of wearing sunglasses during the last 50 or so years might have
any effect as well, I wonder? After all, the eye presumably responds the same
whether it's getting insufficient light because someone is indoors or because
that person is outside but shielding it from >10k lux light with tinted
shades.

~~~
robbiep
The article states that 10k lux is about what you experience when wearing
sunglasses, or sitting under a shady tree

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richthegeek
The summary of this, which was surprisingly difficult to distill, is that low
light levels induces myopia.

Or more specifically, elevated light levels causes a dopamine release which
prevents myopia.

Not sure why the article needed to spend the first 2000 words not just saying
that.

~~~
nn3
Journalists are paid by the word. There is no incentive for being brief (and
not wasting the time of the reader)

~~~
jewbacca
Is this actually true? It's pretty hard to believe, I honestly feel like you
pulled it out of your ass, but it's also possible I'm totally out of touch.

This article is a "feature" (not entirely sure what that implies) in a
scientific journal (targeted towards a relatively general audience, compared
to other scientific journals). Is this particular publication, or this type of
publication, known to pay by the word?

Which other publications pay by the word?

Is it more common in some areas of publication than others?

How could such an incentive-perverting mechanism not have died off by now?

Do any companies still pay/evaluate their developers by lines of code written?

~~~
chc
I used to work in newspapers and it's still pretty common in that industry.
But they also usually give you a word count to hit, so it's not like you can
just write yourself a Mercedes.

------
hnsighty
All right. What you don't want to do is increase _artificial_ light intensity.
A big part of the issue is the light spectrum and distribution of it. There is
a pretty easy way to test / verify this, if you have an eye chart handy.
Compare your acuity in outdoor, shaded light, to a solely fluorescent lit
environment. Once you get to where you can barely make out the line, note the
difference in acuity natural vs. artificial light.

Also, the minus lens creates focal plane stimulus inside the eye that prompts
axial elongation. Lots of studies on this subject, it's basically uncontested.
What you really don't want to be doing is wear a lens that gives you sharp
distance vision, while working up close. You want to have a specific reduced
prescription for close-up, that just gives you correction to the distance you
need.

Breaks, also. Initial myopia is a ciliary (focusing muscle) spasm. Lots of
studies there too, look for pseudo myopia or NITM (near induced transient
myopia). Part of your current deficiency is ciliary, part is axial elongation.
Take an hour break every three hours. Get outside. Focus at a distance. Your
ciliary muscle isn't meant to be all tensed up (close-up use) all day.

For more on the subject, take a look at www.frauenfeldclinic.com, those guys
are fairly awesome.

~~~
jychang
> Compare your acuity in outdoor, shaded light, to a solely fluorescent lit
> environment

The amount of light in the shade outdoors, or on an overcast day, is around 12
EV [1]. A bright indoors office with fluorescent lights is around 8EV. This
means that the human eye will be receiving 16 times more light in the outdoor
shade, compared to even a bright indoors room. That's a big difference that
has nothing to do with the source of the light.

Common sense also dictates that fluorescent lights did not get popular in
homes until the last 10 years due to the rise of CFLs, and yet kids grown up
in the 1970s have increased myopia rates- the source of the myopia therefore
cannot be due to the indoor lights.

[1]
[http://en.wikipedia.org/wiki/Exposure_value](http://en.wikipedia.org/wiki/Exposure_value)

------
xiaq
> About one-fifth of university-aged people in East Asia now have this extreme
> form of myopia, and half of them are expected to develop irreversible vision
> loss.

Which means that 10% of university-aged people in East Asia are going to
develop irreversible vision loss. This sounds too terrible to be true. Am I
missing something here? I interpret vision loss as blindness, but maybe it is
used to describe degraded vision instead?

~~~
brianshaler
People in the US often use the phrase "legally blind" while they can see just
fine given sufficiently corrective lenses. Let's hope it's that.

~~~
mhurron
Then they're using the term incorrectly. Legally blind is having 20/200 vision
in your best eye with the best correction possible.

------
jbritton
I have wondered why the eye stays elongated. My quest for answers has been
from dubious sources on the internet and so everything said below is suspect.
It is all based on reasoning and thoughts from potentially bad information. I
read that the eyeball is a sack filled with a viscous fluid, and therefore,
its shape is determined by the eye muscles. I determined the viscosity of the
eye fluid is thicker than water, but less than motor oil. The idea behind the
eye muscles is that near work puts tension on the muscles and they stiffen up
and thus elongate the eyeball. So now I wonder why the eye muscles don't
relax. Surely, a good night’s sleep or two would do the trick. Could the eye
muscles return to their proper position by not wearing my glasses and spending
more time focusing on distant objects? After about 3 years of experimenting
with this thought, my vision has not improved. But I work indoors in front a
computer everyday with glasses on. I have read the eyes muscles lack any
counter force to pull the eyeball back into shape. Perhaps the eyeball shell
has grown deformed and it is stiff enough to hold the shape. Maybe the eye
socket determines the shape. Maybe the eye muscles have nothing to do with the
shape. I would like to think that there is some corrective measure built into
the eye system. Otherwise, it would seem everybody's eyes are on a one-way
trip to becoming myopic and only the speed of this transition can be affected.
I know that for me, I wore my glasses all the time, even when I was reading.
Looking back, when I was first diagnosed, I really only needed them to play
baseball at night under the lights. I sort of wished that was the only time I
wore them. I wonder if my eyes could have corrected themselves. Now it seems
too late, because I need to wear them just to read a computer screen 18" away.
I have also read that wearing glasses forces your eyes to focus at a close up
distance. So wearing glasses is like doing near work all the time and thus
puts you on the fast track to becoming more myopic. After all this rambling, I
guess the real question is what is keeping the eyeball in the wrong shape? If
this were known, then maybe one could figure out how to fix the condition. As
a final note, I have also read that maybe the eye ball is not elongated, but
that the cornea is not shaped correctly.

~~~
codexon
I have thought about this myself, but I thought that elongation being
permanent or difficult to reverse was intuitive. If you stretch a piece of a
plastic it stays that way.

I believe the prevailing theory is when you focus near, your lenses expand
pushing on the aqueous humor, causing expansion of the eyeball. When you focus
far, they shrink, but these lenses don't pull the eyeball back in because they
aren't connected to the front or back of the eyeball. This is why people with
myopia often have increased intraocular pressure. I don't understand how this
fits in with the findings in this article though.

I have never heard of anyone becoming less nearsighted. And even presbyopia is
simply when your lens cannot change anymore, it doesn't actually shrink your
eyeballs.

It seems like the optical industry is content with making a lot of money
constantly prescribing stronger glasses every year or lasik which has
significant risks and doesn't stop the elongation.

Whoever cracks this problem will make a lot of money. But shrinking eyeballs
is probably a very difficult task and easier and very profitable to just fix
the symptoms. And most people don't become blind from this so it doesn't seem
like a priority.

~~~
nether
> I have thought about this myself, but I thought that elongation being
> permanent or difficult to reverse was intuitive. If you stretch a piece of a
> plastic it stays that way.

May be different for living tissue. I wonder if there might be some brace
developed to reshape the eye ball, that could be eventually removed. Of course
the implant procedure might be incredibly, prohibitively invasive.

~~~
infofarmer
There's scleroplasty, developed and only practiced in Russia and some other
ex-USSR countries. Seems dangerous, but somewhat effective (if you trust
Russian research results):
[http://www.nature.com/eye/journal/v24/n7/full/eye2009322a.ht...](http://www.nature.com/eye/journal/v24/n7/full/eye2009322a.html)

------
yarone
Between the ages of 15 and 17 years old, I spent hours every night in a dark
room in front of a (really bad) 14" CRT display.

I never had issues with my vision. Then I developed Myopia. I have always felt
that it was related to my late night computing.

~~~
lvs
Same thing, around the same age. A somewhat famous ophthalmologist who did a
decent amount of research insisted to my mother, at the time, that there was
no statistical correlation between CRT use and myopia. Interesting to see the
consensus move since then...

~~~
Spooky23
CRT use != low light conditions. I bet the studies were focused on eye strain
in work environments.

------
jvvw
I became curious about this when I became significantly less short-sighted
during each of my years of maternity leave. A few more kids and I won't need
glasses any longer :-) Indeed, I spent much more time outside while on
maternity leave than when I was working.

I found this interesting too: [http://www.katysays.com/pumpkin-eyes-and-
pelvic-floors/](http://www.katysays.com/pumpkin-eyes-and-pelvic-floors/)

------
desdiv
I would love to see a second control group where the kids spent 40 minutes a
day inside a 10,000 lux illuminated classroom.

------
tim333
I've always thought eyes work remarkably well for something hacked together
out of meat and jelly. I guess part of that is probably a feedback mechanism
where the growth of tissue is effected by where the image is focused.
Presumably staring at books throws off the mechanism that evolved for gazing
at the scenery. Guess it needs bright light to work?

~~~
erroneousfunk
That's a tempting thought, but if you read the article, it has nothing to do
with where your eye tends to be focused.

------
scotty79
10000 lux is something achievable with 100W of LED light.

Why not, instead of limiting children exposure to computers and kicking them
outside, just paint the wall behind their computer white and point 100W worth
of LEDs at it?

I'm sure (s)he will spend at least 3 hours per day in that environment without
trauma associated with forcefully exposing the child to boredom of outside.

EDIT: Yes, yes. I know. Being outside and kicking ball has lots of other
benefits. But still... People are not doing it today despite potential obesity
that predictably can kill you and they won't start doing it due to potential
myopia that will force you to wear glasses. So why not go with pragmatic
solution?

------
fixermark
This is some fascinating research.

I feel like there should be some other correlates if light is a dominating
factor, such as between geography and myopia (should see some trends around
super-cloudy vs. super-sunny areas).

------
warfangle
Anecdotal, etc, etc:

I was home schooled through fourth grade. Lots of time spent outdoors, even on
school related things (setting up little rubber army men in the sandbox when
studying the revolutionary war, for example). My eyesight was quite good,
despite spending quite some time on the computer (balanced, of course, with
out-door activities).

Half-way through my first year in public school, I needed glasses. My eyesight
went from 20/20 to ~20/80 in less than five months. 20 years later, it's
around 20/300 - though fairly stable for the last ten years.

------
jamesu
As someone whose myopia gets worse every few years, I feel any concrete
research into myopia is a bonus.

------
codexon
I hope this leads to an actual cure for myopia instead of burning off your
cornea to compensate.

------
Theodores
If you don't wear glasses (or contact lenses) then you are in a minority. I am
in this minority and I find it worrying. Who would have thought that all of
those long walks home would be beneficial?

I think that cycling helps my eyesight. If I cycle in to town then, for
survival reasons, I am fully testing out my eyes. It does not matter what time
of day this is, going through traffic or rolling home late at night on empty
roads, I am really working those eyes. I get to look to the far horizon as
well as those quick glances over the shoulder. Thinking about it, I cannot
think of a better eye exercise!

As well as the normal light I also get enhanced levels of UV reflected from
the road during the summer months.Normally we try to bar UV with glazing so I
am just rebalancing the spectrum if non-visible light is bouncing off the
tarmac.

So, if I was calling the shots here on planet earth I would mandate that all
children cycle to school. For comedy value I would make the punishment for
those that drove their kids in be harsh - eyes scooped out and donated to
medical science. For now, in the run up to the introduction of that I would
want public information campaigns that just tell parents that driving their
kids to school makes them go blind, which is totally true.

------
deegles
So would installing much brighter lights indoors help mitigate this? What does
it take to illuminate a room at the suggested 10k lux?

~~~
ethanmad
It's a good question, but it seems unlikely to be feasible given that "a well-
lit office or classroom is usually no more than 500 lux." I have a hard time
believing that it's 20 times brighter outside than inside, but then again I
have no issues seeing my phone's or laptop's screen indoors, while it's almost
impossible outside (even in the shade) to see anything.

~~~
mkesper
No need to believe here, there are possibilites to measure that.
[https://en.wikipedia.org/wiki/Lux](https://en.wikipedia.org/wiki/Lux)
[http://www.wikihow.com/Measure-Light-
Intensity](http://www.wikihow.com/Measure-Light-Intensity)

------
lamont100
An opthamologist in Finland advocates the use of plus glasses for children
(and everyone else) for all close work to prevent myopia.

~~~
RealityVoid
A small anecdote:

I was diagnosed with myopia at around 7 years of age. I had -1. I went and got
prescription glasses. The guys there fudged it up and gave me +1. I wore those
for more than a year, but I could not, for the love of me, see with them. My
parents were FURIOUS I did not wear them. I kept telling them I couldn't
actually see anything with them. They made things worse. But no dice, they
thought I was just being stubborn. Anyways, I get another checkup after a
year, they realized the error.

On the second checkup, I had -1,75. Either the +1 glasses exacerbated my
myopia, did nothing for it, or actually helped curve it, I could not say. I
think it made things worse. And it was a pain in the ass having to wear
something that made things worse and have people lash on me because they
thought I was just being stubborn by not wearing them.

~~~
masomenos
With plus lens therapy, you only wear the plus lens while doing close work. If
you were wearing the plus lenses while looking more than a few feet away, you
wouldn't be doing plus lens therapy.

------
ajhit406
I laughed to myself after reading the first few paragraphs. When I saw the
image of young Chinese students I immediately thought of the literary use of
myopia, not the medical condition. Given the source of the article was
“Nature”, I assumed it was an article about the Chinese exploitation of
natural resources for the sake of short term profits and the destructive
effect on the environment; hence, myopia. Is that irony?

------
ars
It's interesting that the widely derided See-Clearly method has as one of the
exercises staring at a bright light bulb with the eyes closed.

------
lamont100
An opthamologist in Finland advocates the use of plus glasses for children,
for any sort of close work to prevent myopia.

~~~
hnsighty
Kaisu. She's a bit nutty perhaps, but knows what she is talking about. Only
works before you start to get into more than pseudo myopia (since at that
point you just can't see anything with a plus lens).

~~~
masomenos
you can get the same effect with whatever is a plus lens for you, though. So
if your normal rx is -1.5, do close work without glasses.

------
throwaway43
Since a lot of people are chiming in with anecdotal evidence I'll add some of
my own.

There's circumstantial evidence to suggest that eating white rice can
exacerbate myopia. And asians eat lots of white rice. I found my eyesight
deteriorating and cut white rice out of my diet. I think it's stopped now.

~~~
danparsonson
But then Asians have been eating white rice for centuries haven't they?

~~~
lubos
Not to mention, myopia in Asia is the prevalent in dense populated areas such
as Singapore, South Korea or Japan where rice consumption per capita is lower
than anywhere else in south-east Asia since they can afford more variety of
food when compared to Vietnam, Thailand or Philippines.

You could almost make an opposite case that rice consumption decreases myopia
but most likely there is no link whatsoever.

------
scotty79
> well-lit office or classroom is usually no more than 500 lux

I guess we need to update what "well lit" means.

~~~
sampattuzzi
It won't be long until we "solve" this problem by buying special lamps.
Anything to avoid our children going out into reality!

------
msie
I think I got lots of sunlight as a kid but I don't think I slept properly so
my circadian rhythm was disrupted all the time. I blame it on getting up early
for school and sleeping late because of David Letterman.

------
tomphoolery
One could easily find a correlation between my need for glasses and the time
at which I (and a lot of others) began using computers heavily, like being on
a computer for more than 8 hours a day.

~~~
anon4
I, on the other hand, started using a computer heavily about 5 years after
getting my first pair of glasses. Some of it is just genetic and not all
myopia is preventable with just more time outside.

------
m0skit0
So you're telling me, acquired traits are inherited?

------
shiggerino
I always wondered why I had an entire childhood of obsessive close work
(computer, Lego, drawing, etc.) yet have better vision than my parents had at
my age. I don't know if computer screens are bright enough to have a
protective effect, but I did grow up in a culture insistent on kicking kids
out of the classroom for breaks no matter the weather.

