SYDNEY (AFP) - Spending a couple of hours outdoors each day could help children avoid becoming short-sighted, Australian researchers said Tuesday.

Exposure to bright light for two to three hours daily helps regulate the eye's growth, dramatically reducing the risk of myopia, an Australian Research Council study found.

Short-sightedness, traditionally a problem among the highly educated, has reached record levels in east Asia, lead researcher Professor Ian Morgan told AFP.

Growing numbers of children in Hong Kong, Taiwan, Japan, Korea and China are struggling with their vision, with up to 90 per cent of Singaporeans wearing glasses by the time they leave school, he said.

"That would compare with about 20 percent of Australians. We were quite intrigued by this - that for a country that's quite well educated we have a serious lack of myopia in Australia," Morgan said.

A comparative study showed 30 percent of six and seven-year-old Singaporean children had already developed the condition, compared with just 1.3 percent of Australians of the same age.

The figures were similar when contrasting children of Chinese descent from both nations, allowing researchers to eliminate ethnicity as a factor.

The one significant difference between the populations was time spent outdoors - children from Singapore spent an average 30 minutes outside every day, compared with two hours for the average Australian.

Both groups spent about the same amount of time reading, watching television and playing computer games, debunking the theory that flickering screens were ruining children's eyes, he said.

"There's a driver for people to become myopic and that's education," Morgan said. "And there's a brake on people becoming myopic and that's people going outside."

"What we would suggest is that what's happened in east Asia is that they have got the balance totally out of kilter."

The study is part of a long-term project on eyesight at the government-funded council.