Interesting

Myopia, the medical condition commonly referred to as nearsightedness has doubled in the United States and is up by 80 percent in China. Scientists now think they have determined the surprising reason why according to Nature.

And no, its not because we are constantly focused on our TV’s, computers and cell phones.

Sixty years ago, under 20 percent of the Chinese population had myopia. Today, it is estimated that as many as 90 percent of teenagers and young adults in that country have trouble seeing objects in the distance. Similarly, about half of the young adults in the U.S. and Europe are nearsighted, which means the percentage of cases in these populations has doubled over the last 50 years.

Myopia is a medical condition where people have a slightly elongated eyeball. While we can correct nearsightedness, typical treatments like glasses or surgery do not cure the underlying condition. In severe cases, it can cause more serious complications leading to total vision loss.

Doctors and scientists have historically attributed myopia to genetics and lifestyle factors. On the surface, the rates of myopia are increasing in lock step with longer hours spent studying and using handheld devices. So it seemed plausible that this was the cause. But surprisingly, it seems that this is not the case.

Researchers now believe simply spending too much time inside is causing the problem.

Some scientists have concluded that the increased incidences of myopia are a result of decreased exposure to bright, natural light – regardless of the activity.

Put more simply, spending less time outside seems to be hurting our ability to see things further away.

Like any scientific findings, researchers point out that more data is needed to confirm the theory, though some similar research on animals does appear to support the hypothesis.

Elie Dolgin’s report in the science journal Nature, explains that light stimulates the release of dopamine in the retina, and this neurotransmitter in turn blocks the elongation of the eye during development.

Based on epidemiological studies, Ian Morgan, a researcher at the Australian National University in Canberra, recommends that children spend three hours per day under light levels of at least 10,000 lux for protection against myopia. Ten thousand lux is about the amount of light exposure beneath a shady tree on a bright summer day (while wearing sunglasses). A well-lit schoolroom or office is generally under 500 lux.

In Australia, where 3 hours of outdoor time is typical for children, only 30 percent of 17-year olds are nearsighted. In the U.S. and Europe where myopia rates are higher, many children only get an hour or two of outdoor time per day.

In 2009, Morgan began testing whether or not adding outdoor class time to school schedules, would reduce myopia rates. The initial results from China and Taiwan appear to show measurable decreases in nearsightedness from the children who spent more time outside.

For schools where outdoor play options may not be as readily available, Morgan is also looking into pilot projects where gymnasiums can be built or renovated to allow more natural sunlight.

Sadly, there have been some reports in the United States where parents have actually been arrested for letting their children play outside.