Study: Sunlight can help children avoid myopia: Aussie researchers 2009
Children should spend two to three hours a day outside to prevent them becoming short-sighted, says a study by the Australian Research Council Centre of Excellence in Vision Science.
A comparison of children of Chinese origin in Australia and Singapore, which has the highest rate of myopia in the world, found the only significant difference was the time spent outdoors.
Ian Morgan from the ARC Vision Centre yesterday said exposure to daylight appeared to play a critical role in limiting the growth of the eyeball, which is responsible for myopia or short-sightedness.
Professor Morgan said it had been apparent for a couple of hundred years that more educated people were short-sighted, but the research suggested spending some hours a day outdoors could counteract the myopic effects of study.
"Video games are as ineffective as reading on vision," he said. "Computers are pretty neutral, watching television doesn't seem to affect vision. The only difference we could find is the amount of time spent outdoors.
The research says about 30 per cent of six-year-olds in Singapore are short-sighted enough to need glasses, compared with only 3 per cent of Chinese-Australians.
Both groups spend the same amount of time studying, playing video games, watching television and reading books. But Singapore children spend an average 30 minutes a day outdoors compared with two hours in Australia.
Professor Morgan said similar trends were seen in India, with 5 per cent of rural-dwelling Indians being short-sighted compared with 10 per cent of their urban cousins and 65 per cent of those living in Singapore.
Myopia is increasing in urban areas around the world, and is described as an epidemic in parts of east Asia, with Singapore the world capital.
Australia has a level of myopia more commonly found in the Third World, with only 0.8 per cent of six-year-olds of European origin being short-sighted.
They spend on average three hours a day outdoors.