Exposure to sunlight stop children from becoming near-sighted. Researchers have found that the time children spend outdoors is a critical factor.
A comparison of children of Chinese origin living in Singapore and Sydney, Australia, showed that the rate of myopia in Singaporean children is 10 times higher. But the children in Sydney spent significantly more time in near-work activity such as reading books, which has long been held to be the principle cause of myopia.
However, the Sydney-based children were also outside almost four times longer than their Singapore counterparts.
Exposure to sunlight may cut myopia rates by encouraging the release of dopamine, which is known to inhibit eye growth; myopia is a condition caused by excessive eye growth.
* ABC Science Online December 5, 2007