Increasing exposure to outdoor light is the key to reducing the myopia or short-sightedness epidemic in children, researchers said.
"While screens are contributing to children spending more time indoors than in previous years, the research shows they are not the direct cause of the increased incidence of myopia," said Scott Read from Queensland University of Technology in Australia.
"Optometrists need to make their patients aware that less than 60 minutes' exposure to light outdoors per day is a risk factor for myopia. It looks like even for those with myopia already, increasing time outside is likely to reduce progression," said Read.
"Children exposed to the least outdoor light had faster eye growth and hence faster myopia progression," said Read.
A recent study predicted that half the world's population will be short-sighted by 2050 with many at risk of blindness.