In a matter of just two generations myopia or shortsightedness has risen from 20 to almost 90 percent in East Asian city dwelling children. And it turns out that in most cases it's not a genetic disorder but rather an environmental factor.
Children who live in cities in China, Taiwan, Hong Kong, Japan, Singapore and South Korea are faced with massive educational pressures. In addition, many East Asian cultures promote staying inside during lunchtime and having a nap.
When East Asian children aren't in school they are inside watching television, playing video games or reading. On average East Asian children are spending only 30 minutes each day outside exposed to sunshine or filtered light from an overcast sky.
According to Professor Ian Morgan of the Australian National University the reason for the dramatic rise in shortsightedness amongst East Asian city dwelling children is due to a lack of exposure to sunshine.
Exposure to sunshine stimulates the body's production of a chemical called dopamine, which is known to prevent the eyeball from elongating and in turn distorting the focus of light entering the eye.
Australian children spend up to three hours a day outside and shortsightedness amongst their youth is about 10 percent. The rate amongst children in Britain and the U.S. is higher at about 35 percent whilst in Africa it's only about 3 percent.
Clearly, this recent study highlights the importance of children getting outside to help maintain healthy eyes. Moreover, getting children to play outside and involved in physical activity helps protect them against the onset of type II diabetes and obesity, vitamin D deficiency and osteoporosis.
Besides, spending a couple hours daily exploring the great outdoors is fun. And it's a terrific way to foster an appreciation for the wonders of nature.
Earth Dr. Reese Halter is a distinguished conservation biologist, award-winning science communicator and author of The Incomparable Honeybee and The Insatiable Bark Beetle.