Genes not responsible for myopia, researchers say

East Asians are no more genetically prone to myopia than other ethnicities, according to a group of researchers in Australia who analyzed past studies.

Ian Morgan and Kathryn Rose of the University of Sydney say the higher rates of myopia in countries such as Singapore and Japan are directly related to lifestyle and not genetic makeup. In Singapore, for example, 80% of 18-year-old army recruits are myopic, up from 25% 30 years ago. According to the researchers, the true cause of myopia is the increased amount of near work children now do, such as playing video games or computer work.

The researchers found 70% of 18-year-old men of Indian descent living in Singapore have myopia, compared with 10% of Indian men living in India. Similarly, the rate of myopia for male adolescents age 14 to 18 in Israel is 80% in schools that emphasize reading religious texts, compared with 30% in state schools.

“The simplest explanation is that you have a massive environmental effect that is swamping out the genetic influence,” Mr. Morgan said in an article in New Scientist.

The researchers note lifestyle is affecting myopia rates outside of Asia as well. In Sweden, 50% of 12-year-old children are myopic; the researchers expect that figure to be more than 70% when those children turn 18.

The study will be published in Progress in Retinal and Eye Research, according to the article.