February 11, 2013 10:57 am
All Those Hours Inside Could Make You Nearsighted
Image: clappstar
Hey, you, reading this on the computer screen, you’re hurting your eyes. In fact, just by being inside all the time, you might be helping to create a population full of nearsighted people. The rate of nearsightedness has increased constantly in the past decades, Science News writes, and it might be because we’re always indoors:
Studies first uncovered a link between myopia and limited outdoor time during childhood just a few years ago. At the time, many researchers were taken aback. The notion that child’s play might promote normal eye growth seemed almost magical.
Eyeballs, which develop mostly in infancy, with some changes continuing through adolescence, can be all sorts of shapes. People with myopia have eyeballs that are slightly longer, which keeps images from being focused neatly on their retinas. To a certain extent, nearsightedness is genetic, but kids who stay inside a lot also might wind up with longer eyeballs, since they never have to look out into the distance. One study found just that—kids who spent more time indoors were more likely to become nearsighted during elementary school than those who played outside.
It’s not actually clear, though, that playing outside can help stop nearsightedness, says Jeremy Guggenheim, an optometrist who talked to Science News about myopia:
It’s tantalizing to think that time spent outdoors early in life might fend off the need for eyeglasses, contact lenses or laser surgery in many people. But, Guggenheim notes, it is not yet clear to what extent outdoor exposure can cut risk or how it does so. Some scientists say the benefit could come from exposure to natural light, a relaxation of the eye gained from viewing things at a distance or the visual tableau that reaches the eyes’ peripheries while outdoors. Or it could be a mix of all those factors.
As with basically everything ever, there’s probably no single cause for nearsightedness. Genetics, environment and habits all have something to do with it. That means that fixing myopia isn’t easy, especially as, Science News points out, most eye doctors don’t see kids until an eye test at school reveals a problem. At that point, more time outdoors won’t necessarily help them.
And kids are often getting really important benefits, like school or safe playtime with friends, out of their inside time. No one is saying children should be released onto the world to roam about like feral cats for the sake of their eyesight. But if they do wind up needing glasses in the future, all those minutes at the computer might have had something to do with it.
More from Smithsonian.com:
Glasses Let Doctors, Poker Players See Your Blood
The Nature of Glass
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“it might be because we’re always indoors” And it might not! My family has a number of severely nearsighted members in several generations, and only a few of us are indoors most of the time. As with many conjectures from forward thinkers in today’s society, it’s all too easy to draw the wrong conclusion from surface appearances. If it walks like a duck, it’s not always a duck. We are also battered with pesticides and other chemicals, unavoidable in our society. You don’t think. . . .?
Comment by Robin Burns — February 17, 2013 @ 12:08 pm
The problem with correlations is that it’s easy to get cause & effect backwards. Perhaps kids who are nearsighted to begin with stay indoors because they can see close objects more easily than distant objects. If you can’t see a baseball coming towards you until it’s too late to catch it, why play baseball? Much more satisfying to play an indoor game that does not require “outdoor” vision. That is, indoor play is the effect, not the cause.
Comment by Brooks Martin — February 17, 2013 @ 5:05 pm
I don’t see any correlations, just a kind of presumption. Both my parents were near sighted, my sister is near sighted as is my brother. I was probably the worst: 20/400 in one eye and 20/200 in the other. This myopia was not corrected till I was in my 70s and had cataract surgery.
Much of my youth was spent out doors — chasing lizards, looking for frogs or climbing hills around where I grew up. I learned to identify things at a distance by color, general shape and how they moved. It was not till I was in junior high school and had a choice as to where I sat in the class-room (at the back then) that I and the teachers discovered I could not read the black board! Glasses were the solution.
Some think I might have developed my near-sightedness because I read with a flash light under the covers when I had to stay home with the measles.
So I was near-sighted — nothing that could not be fixed by a good pair of glasses and something that may also have increased my acute awareness of what was going on visually around me.
So I was near-sighted — so what?
Comment by Richard Anderson — February 17, 2013 @ 7:27 pm