Excess Time Indoors May Explain Rising Myopia Rates

Nature reports that an unexpected factor may be behind a growing epidemic of nearsightedness: time spent indoors. From the article: Because the eye grows throughout childhood, myopia generally develops in school-age children and adolescents. 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. This threat has prompted a rise in research to try to understand the causes of the disorder — and scientists are beginning to find answers. They are challenging old ideas that myopia is the domain of the bookish child and are instead coalescing around a new notion: that spending too long indoors is placing children at risk. “We're really trying to give this message now that children need to spend more time outside,” says Kathryn Rose, head of orthoptics at the University of Technology, Sydney.

Comments

Surprisingly badly written article

[bargainsale]

"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. "

It doesn't actually say what "this extreme form" is, exactly. Presumably cut out in editing and nobody noticed that this was left stranded. There was probably a reference to so-called "high myopia", which does indeed cause people typically in their teens to go from the ordinary fully-corrected-with-glasses myopia to being much more so, with potential "myopic degeneration" of the retina. It's a mystery why this only happens to some myopes.

The figures are scaremongering. Although this has indeed been a notable public health problem for a good while - the government of Singapore has been concerned about it for over a decade - it is nonsense that 10% of student-age people will go blind from it.

I'm an ophthalmologist. I specialise in diseases of the retina.

Light levels, not computer games

[gringer]

For those who didn't pick up on the bit in the summary, this is not due to close work, it's most likely due to exposure to bright light:

But time engaged in indoor sports had no such protective association; and time outdoors did, whether children had played sports, attended picnics or simply read on the beach. And children who spent more time outside were not necessarily spending less time with books, screens and close work.... Close work might still have some effect, but what seemed to matter most was the eye's exposure to bright light.

If this is the case, then what we should do to reduce the myopia problem is to use brighter lights inside.

Re:Unfortunately

[AthanasiusKircher]

However, the REAL problem is that helicopter mummsy and daddsy are TERRIFIED that pedobear will rape little timmy and throw him away in an old icechest, because Fox News said so.

It's not just Fox News, and it's not just pedophiles. If you've been keeping up with the news in recent years, you know that the newest trend is for do-gooders to call the police when they see even a 9 or 10-year-old walking alone (e.g. back from the park) or sitting in a car reading while Mommy's doing some shopping.

And guess what happens in too many cases? Parents get arrested for neglect. Children sometimes get removed for a while by protective services and parents may need to fight to get them back.

I'd be much more scared of police or child protective services kidnapping my child than "pedobear," because that's certainly the case. (In case you think I'm exaggerating, look up the stats. Roughly a HALF MILLION kids are removed by CPS for short or long term every year in the US... And CPS's own stats admit that in a full 1/3 of those cases, after review there is NO evidence of abuse or neglect... Not counting the cases where the claims are questionable, just the removals where the removals are completely unwarranted.)

Also, here's a blog that keeps track of some of the more egregious stories in the news.

Stop it

[itchybrain]

Stop masturbating, people.

Re:Use it or lose it

[dasunt]

So, as with many of the bodies abilities; it's just a case of use that distance vision, or lose it when your eyes adapt to shorter ranges.

Except according to the article, that isn't the mechanism. It's the intensity of light that causes the body to prevent myopia due to changes in dopamine levels.

Not only that, but in animal studies, if chicks were given a drug that inhibited dopamine's effects on the eyes, they'd develop myopia in the same conditions that the control chicks would not.

So it's not "use it or lose it". It's "you need bright light".