Kids who spend more time outdoors are less likely to be near-sighted, as I noted in a recent post. But it isn’t because they’re spending less time staring at books or computer screens, as I speculated might be the case.
In fact, neuroscientist Sandra Aamodt, whose book I referred to in the previous post, explained in a comment that among children who spend the same amount of time outdoors, how much they read or work on a computer (“near work”) has no correlation with near-sightedness.
In addition, in lab animals, dim light leads to near-sightedness and bright light normalizes sight by affecting eye growth, she said.
Outdoor light is significantly brighter than indoor light, Aamodt told me in a follow-up email: “Indoor light ranges from 100 lux (home) to 500 lux (office); outdoor light from 1,000 lux (dusk) to 100,000 lux (sunny midday). “ (If you’re wondering, one lux is equal to one lumen per square meter. Aamodt says light boxes used to treat depression can produce 10,000 lux.)
So the bottom line remains the same: Spending time outdoors in childhood is associated with better eyesight. But kids don’t have to be hiking or looking over long vistas to get the benefit; they could be reading in the back yard.
Of course there are many benefits to being physically active while outdoors, but apparently better eyesight isn’t one of them.
– Read “The Sun is the Best Optometrist,” a New York Times op-ed on this topic by Aamodt and Sam Wang.
Great Kids, Great Outdoors is an AMC Outdoors blog, written by Kristen Laine and Heather Stephenson. Heather wrote this post.