THURSDAY, Dec. 24, 2015 (HealthDay News) -- Children who spend lots of time indoors and on computers and other electronic devices may be raising their risk for nearsightedness, a panel of U.S. ophthalmology experts suggests.

The prevalence of Americans with nearsightedness -- also known as myopia -- has nearly doubled over the last 50 years, the ophthalmologists noted.

The ophthalmologists suspect the increase is due to "near work" -- focusing on something close to your eyes -- and the decreased amount of time spent outdoors in natural light.

"Kids are spending much more time doing indoor activities with their cellphones, iPads, computers, and so on," said Dr. Rohit Varma, director of the University of Southern California Eye Institute in Los Angeles.

"Especially when children are young, when they play these games indoors where they're seeing things very close to them and doing it in low-light level -- that combination of doing near activities in low light is what contributes to these children becoming very nearsighted," Varma said.

A panel of 10 ophthalmology experts discussed the global increase of childhood myopia at the American Academy of Ophthalmology's (AAO) recent annual meeting in Las Vegas. Information presented at meetings is usually viewed as preliminary until published in a peer-reviewed journal.

Anyone can be nearsighted, but it's more common in people whose parents are nearsighted, said Dr. K. David Epley, a spokesman for the AAO. The condition is also much more prevalent in industrialized and urban areas than in rural areas, he added.

Children of East Asian descent are genetically predisposed to nearsightedness, but children's habits in those regions may be increasing the rates of myopia even more. The current rate of myopia in young people in China is 90 percent compared to about 10 to 20 percent 60 years ago, the experts said. That compares to a rate of 42 percent for Americans between the ages of 12 and 54, according to previous research.

The ophthalmologists noted the difference in Chinese and American work habits. Children in China spend up to 12 hours a day doing near work, compared to their U.S. peers, who spend about nine hours a day on near work, the eye experts said.