Of all the pandemics in the world, here's one I did not know about: myopia. Near sightedness? Are you sure you're not thinking of hyperopia which I and everyone I know has? Yeah, it does seem everyone I know needs reading glasses, but no. I'm referring to young people who can't see far and the reason will make a lot of parents shake their heads: kids are spending too much time indoors.

It's true. For example, in Korea and China where study time has shot up, 90 and 97 percent of young people have myopia. Sixty years ago only 10 to 20 percent of Chinese were myopic! I know it's tempting to believe too much time hitting the books is the problem, but a study in 2000 disproved this theory.

In order to find an answer then, scientists in 2007 followed more than five hundred eight to nine year olds with healthy vision. After tracking their time outdoors over five years, 20 percent had developed myopia and it correlated with the little time they spent outdoors. Scientists in Australia confirmed those results with their study of four thousand students a year later. Here's the reason.

The retina produces and releases more dopamine, a neurotransmitter, during the day to signal the eye to switch from night to day vision. The low light indoors disrupts this cycle which affects the developing eye. They estimate kids need about three hours of outside light daily. If schools mandated even an hour or hour and a half outside, that's been shown to reduce the risk of myopia. That's why kids in Australia who spend more time outdoors have a lower rate of myopia.

Corrective glasses may improve vision but not the inner eye which over time stretches and thins. These kids face a higher risk of eye disorders and even blindness unless we force them outdoors.