For an increasing number of Americans, life’s a blur.
That’s according to a comprehensive study published Monday showing rates of myopia—difficulty seeing distant objects—are soaring. The trend is matched in many other countries worldwide, causing many eye doctors to wonder what could be causing the decline in human vision.
Researchers at the National Eye Institute, part of the National Institutes of Health, found rates of myopia—also called nearsightedness—in people age 12 to 54 increased from 25% in 1971-72 to 41.6% in 1999-2004. The survey included people with a range of myopia, from mild to severe.
The study was published in the Archives of Ophthalmology.
“It’s very intriguing,” said the lead author of the study, Susan Vitale, a research epidemiologist with the National Eye Institute. “It points to the need for research to look at the causes of myopia and factors that could, perhaps, prevent it.”
Myopia occurs if the eyeball is too long or the cornea, the front cover of the eye, has too much curvature. Light entering the eye isn’t focused correctly and distant objects look blurred. The condition usually occurs in childhood. It can continue to worsen until early adulthood.
The survey was based on data from 4,436 black or white Americans from 1971 to 1972 and 8,339 black or white Americans from 1999 through 2004. Rates of myopia increased most dramatically for blacks: from 13% in the first period to 33.5% in the later period.
Part of the increase, in blacks and whites, is likely due to improved access to vision screening and treatment. However, better care doesn’t explain everything. It’s possible that children are spending so much less time outdoors that their eyes become geared to near-vision tasks, such as computer and video games.
For more information on myopia, see this page at the National Eye Institute.
-- Shari Roan
Photo credit: Tomohiro Ohsumi / Bloomberg