Natural Light Away From The Screen Could Help Reduce The Global Myopia Boom

Even as two dozen genes are being picked out as close to shortsightedness, or myopia, genetics is also important, say medical experts. In a study of more than 45,000 from Europe and Asia, 24 new genes have been identified, of which two are said to trigger shortsightedness, reported British researchers in the journal Nature Genetics last year, according to hindustantimes.

Hence, if you inherit some of these genes, you expose your eyes much more to shortsightedness.

"An interaction between genes and the environment is believed to trigger myopia," says Dr Sri Ganesh, chairperson and medical director of Nethradhama Super Speciality Eye Hospital, Bangalore. "Ambient light levels in childhood are thought to affect the growth of the eyeball, with poorly-lit environments and prolonged indoor activity aggravating the problem."

In myopia, the eyeball grows long, so that light gets focused "just short of the light-sensitive retina at the back of the eye."

Published in February, the study reported that scientists watched 10,000 students in private and government schools in Delhi and discovered 13.1% children "at a mean age of 11.6 years" as near-sighted.

In the U.S. too, the rate of nearsightedness in people 12 to 54 years old increased by nearly two-thirds "between studies nearly three decades apart ending in 2004, to an estimated 41.6%, according to a National Eye Institute study," according to wsj.

Various parts of the world have shown a dramatic increase in the condition of myopia, which inflicts half the young adults in the US and Europe. This is double what it was half a century ago. Some estimate that one-third of the world's 2.5 billion people may contract short-sightedness by the end of this century.

"We are going down the path of having a myopia epidemic," says Padmaja Sankaridurg, head of the myopia programme at the Brien Holden Vision Institute in Sydney, Australia, according to nature.

Myopia shoots up when children read for more than five hours a day, watch television, or use computer, video and mobile games for more than two hours.

The study showed that just 5% shortsighted children were active for more than two hours outdoors, compared with 47.4% of children with normal vision, and less than one in four (24.7%) children wore the correct spectacles.

"Prolonged close work, looking at a book or screen at a distance of less than 30 cm for more than two hours a day causes eyestrain and reduces blinking rate, signs of which include blurred vision and watery eyes," says ophthalmologist Dr Ritika Sachdev, director, medical services, Centre for Sight. "Add to this reading in poorly-lit rooms, and you have children rapidly losing the eye's focusing ability. Other than surgery, while the options to reduce progression of myopia are very limited,"

Adds Dr Sachdev: "A drug called atropine reduces progression but I don't prescribe it, as it dilates the pupil and causes issues with light sensitivity and difficulty in reading."