This is a scientific Americans 60 second science. I'm Steve Mursky. Got a minute?

So we're inside, we're in fake lighting, we're not spending as much time outside in the context which our visual system evolved.

Amanda Maline, assistant professor of anthropology and archaeology and of medical genetics at the

University of Calgary, and all that sitting inside in dim light staring at screens has led to an

epidemic of myopia near-sightedness among young people. The myopia

epidemic is particularly strong in Asia and in urban Asian environments where it is increasing to be upwards of 90% of teenagers are myopes.

Malin spoke February 20th at a press briefing at the annual meeting of the American Association

for the Advancement of Science in Boston.

So to be sure there's a genetic component, my father had glasses, I have glasses, but we're increasingly realizing

that the environments in which we're spending our time are playing a major

role. And so a cohort study where some school-age children were given 40 minutes or more time outside.

Those children had a 23 to 50 percent less likely chance of developing myopia than students at schools who are not

given that same amount of outdoor exposure and it looks to be dosage

dependent so the longer time you spend outside the less chance you have of

developing myopia. So the exact mechanisms are not really known so we really need a lot more

research into this but another major factor that's being implicated is near

work activities so spending our times looking at computers into microscopes,

these things and then as soon as we leave our work what are we doing? We're on our

mobile devices that's also a very close activity. When we're engaged in near focused tasks our eyes are

actually working really hard because the muscles have to accommodate the lens

to focus that close. We would look off into a distance that's when our eyes are

relaxing. So there could be something with that as well.

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