Life & Style | Health

Why Chinese children are developing myopia

Experts blame educational pressure and the disappearance of a strong preventive agent — time outdoors

By Nicole Liun, Los Angeles Times
Published: 00:00 July 22, 2012

Students at Bayi Xiwang elementary and primary school

Image Credit: Los Angeles Times
Students at Bayi Xiwang elementary and primary school in Guangzhou, China, are given 45 minutes of outdoor instruction each day in a clinical trial aimed at offsetting myopia.

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Guangzhou, China: The children at the Bayi Xiwang elementary and middle school are doing something revolutionary by current Chinese standards: They’re playing outside. Singing and skipping in the dizzying southern Chinese humidity, these students have been given 45 minutes a day to frolic under the sun while peers across the nation remain indoors, hunched over books or squinting at blackboards.

By forcing youngsters to put down their pencils and expose their eyes to natural light, researchers think they can stem an explosion of near-sightedness in China.

By the time they complete high school, as many as 90 per cent of urban Chinese youth are afflicted by the condition known as myopia, in which close objects can be seen clearly but things just a few metres or centimetres away start to blur.

Even more troubling is the severity of the Chinese cases. Between 10 per cent and 20 per cent of near-sighted Chinese children are expected to develop “high myopia”, which is largely untreatable and may lead to blindness.

“The problem for China is really quite massive,” says Ian Morgan, a visiting professor at the Zhongshan Ophthalmic Centre at Sun Yat-sen University who helped organise the three-year clinical trial in Guangzhou.

“Their best-educated kids — kids who are going to be the intellectuals or political leaders — are going to be progressively losing vision as they get older.”

Experts remain divided on how much genetics is to blame for China’s struggle with myopia. Scientists have found more than two dozen genes linked to the problem, especially for the most severe forms of the condition. Children whose parents have myopia are also more likely to develop near-sightedness. But Morgan, an Australian, is trying to prove its origins are largely environmental and linked to schooling.

Near-sightedness is rampant in the Asian Tiger economies of Hong Kong, Taiwan and Singapore where academics are similarly rigorous, even among children who aren’t ethnic Chinese. For example, research has shown that students of Indian ancestry living in Singapore have rates of myopia eight to nine times higher than their peers living in India, Morgan said.

Fishing for older records in China, Morgan and his colleagues found studies that showed the condition affected about 20 per cent to 30 per cent of young adults in Guangzhou in the early 1970s, near the end of Mao Zedong’s violent Cultural Revolution. Schools and universities were closed, intellectuals purged. Some victims were targeted for merely wearing spectacles. But today, students are more dependent on glasses than ever.

Myopia has steadily increased in concert with China’s urbanisation and intensified academic competition. It’s not uncommon for children to study four hours a day at home on top of a full day of school as well as attend several hours of tutoring on weekends.

“Parents want their kids to get into the best primary school so they can have a better chance at the best high school that can help them get into Beida, Tsinghua and Fudan,” Morgan says, referring to China’s three elite universities. “Educational pressure and the disappearance of a strong preventive agent — time outdoors — is driving kids to myopia.”

Even China’s authoritarian leaders have had to ask schools to ease off. In 2010, several provinces banned public pre-schools from instructing three-year-olds to memorise ten Chinese characters a day.

Despite a 2007 order by Chinese authorities to boost physical education in schools to combat obesity and deteriorating eyesight, many educators — and parents — have resisted. Morgan and fellow researchers at the Zhongshan Ophthalmic Centre had to negotiate hard to persuade six schools to allow students a daily recess break.

Morgan wanted more than an hour of outdoor exercise a day. The schools agreed to 45 minutes and structured lessons in the open air, sometimes with singing, dancing and the occasional hula hoop. “We roll out a blackboard onto the playground and create situations where the students can practice English with each other or draw outside,” said Wang Xiaojia, Bayi Xiwang’s principal.

The researchers acknowledge this may be as close as they get to giving young Chinese eyes a break. “If your prescription at the end of the day is making Chinese care less about education, then it’s not going to happen,” said Nathan Congdon, a professor at the Zhongshan Ophthalmic Centre.

“That’s like telling Americans to like basketball or football less.”