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.
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