Myopia, the blurry vision we know as nearsightedness, is reaching epidemic proportions—it could overtake a third of the world’s population by decade’s end. But is the condition caused by the rise of computers and mobile devices that strain the world’s eyes? It turns out that tech can cause nearsightedness...but not in the way you might think.
Scientists are increasingly linking myopia with time spent indoors, reports Ellie Dolgin for Nature. She notes that scientists have long been on the hunt for the cause of myopia, which has been linked to higher education levels, genetics and book work over the years. But though researchers have been unable to find a link between specific computing or reading behaviors and myopia, says Dolpin, they did find a connection between eyesight and the amount of time spent indoors.
As we spend more time indoors consuming technology, it appears that our susceptibility to myopia rises. But Dolgin reports that there’s a way to protect your eyes from the condition:
Based on epidemiological studies, Ian Morgan, a myopia researcher at the Australian National University in Canberra, estimates that children need to spend around three hours per day under light levels of at least 10,000 lux to be protected against myopia. This is about the level experienced by someone under a shady tree, wearing sunglasses, on a bright summer day. (An overcast day can provide less than 10,000 lux and a well-lit office or classroom is usually no more than 500 lux.) Three or more hours of daily outdoor time is already the norm for children in Morgan's native Australia, where only around 30% of 17-year-olds are myopic. But in many parts of the world — including the United States, Europe and East Asia — children are often outside for only one or two hours.
That insight could help put a stop to the growing tendency towards myopia. In the United States, it grew 66 percent between 1971 and 2004. But though the National Eye Institute estimates that 33 percent of Americans have myopia, the number is much higher in children—and in countries like China, nearsightedness rates are as high as 86 percent in some cities. And Dolgin notes that it’s even worse in Seoul, where more than 96 percent of 19-year-old men have myopia.
Research on how light affects myopia is still ongoing, and there’s fierce debate about not just how to get kids outside, but how to supervise them once they’re there. And though it’s not clear how long it will take for science to focus the world’s vision, a new pair of glasses might help you focus on your work—these experimental eyeglasses use neurofeedback to get you back on task.