Parents everywhere were vindicated today when a report in Nature revealed that, yes, we should definitely be spending less time on the computer and more time outside. Besides the obvious health benefits of exercise and vitamin D, being outdoors might help protect your vision, the report says. There has been a boom in myopia, a.k.a. nearsightedness, in recent years. The report's authors note that about 60 years ago, only 10% to 20% of the Chinese population was nearsighted, but today that percentage is already at 90% among teens and young adults. More than 40% of the U.S. population needs glasses to correct their nearsightedness, and it’s likely one-third of the entire world’s population could have myopia within the next ten years, according to Popular Science. Researchers who have been trying to find an explanation for the sudden uptick in nearsightedness think they've found the culprit: The great indoors. A 2007 study looked at 500 children with initially good vision and found, as the Nature report summarizes, that “after five years, one in five of the children had developed myopia, and the only environmental factor that was strongly associated with risk was time spent outdoors.” Then, in 2008, an Australian study produced the same results. After tracking 4,000 children over three years, researchers learned that those who were outside less were also at a greater risk of myopia. Scientists aren't exactly sure why being outdoors can help, but they think it's sunlight that may protect against myopia. Of course, nearsightedness can be easily treated with some specs, but as Popular Science explains, “nearsighted people are at a higher risk for glaucoma, retinal detachment, and cataracts.” Yet another good reason to commit to getting up from your desk now and then for some fresh air.