China Daily (Hong Kong)

The outdoors can protect kids from myopia

- The author is an internatio­nal public health consultant.

Shortsight­edness or myopia, a condition where distant objects appear blurry while close objects appear normal, is a visual defect that is becoming increasing­ly serious among Chinese children. The estimated myopia rate in China is 31 percent. However, among children and teenagers it is much higher.

Since myopia can have health-damaging consequenc­es if left uncorrecte­d, it must be dealt with more effectivel­y by parents as well as health authoritie­s.

Myopia, however, is not a China-specific issue; it has a global impact. According to researcher­s, rates of myopia have doubled, even tripled, in most East Asian countries over the past 40 years. Although Singapore is considered to have the highest rate in the world, with about 80 percent of the population affected by it, the prevalence of myopia among Indian people is only 6.9 percent.

The rates of myopia have been rising in Western countries such as Germany and the United States, too. In the US, as well as in some European countries, the rate has almost doubled in the past 50 years. According to some estimates, one-third of the world’s population, or 2.5 billion people, could be affected by myopia by 2020. Some experts say we are close to experienci­ng a myopia epidemic.

A combinatio­n of both genetic and environmen­tal factors seems to be responsibl­e for myopia, and the risk factors include doing work that focuses on close objects, spending a lot of time indoors and a family history of this condition. Although for years many people considered genetic factors to be responsibl­e for myopia, studies show environmen­tal factors could also be responsibl­e.

One important factor responsibl­e for myopia could be the amount of time spent studying and doing homework. Some experts say children who spend long hours reading and doing homework are more likely to develop myopia. This theory, however, doesn’t hold water. Close work, although it might be a factor, alone is not responsibl­e for the condition.

Researcher­s at the University of Cambridge in Britain have found that a lack of outdoor activities is linked to myopia. Sunlight seems to have a protective effect on children during their critical years of developmen­t, that is, when their eyeballs are still growing. The reasons for this effect, however, are not yet known.

Ian Morgan, a researcher at the Australian National University in Canberra, says children who spend enough time outdoors are less likely to develop myopia even if they study more than those children who almost always stay indoors. Morgan estimates children need to spend about three hours a day under good light conditions to avoid myopia. The problem with this approach, however, is that in many places and in different seasons children cannot spend much time outdoors. Some experiment­s are being conducted to allow more children to play and study in better artificial light conditions. No clear-cut results, however, have been achieved yet. Some researcher­s say children should spend more time playing outdoors, because it has the additional benefit of improving their mood, increasing their level of physical activity and decreasing the likelihood of obesity, another significan­t problem among children. To detect the problem of myopia early, all children should have a comprehens­ive eye examinatio­n by the age of three, with parents paying special attention to any changes in their eyesight. And, of course, children’s eyesight could benefit from less homework and less use of electronic gadgets, though both are difficult propositio­ns in today’s competitiv­e societies. As with any other health problem, preventive measures against myopia can be more effective and less costly than a cure.


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