Half of U.S. Adults Lack 20/20 Vision

Aug. 12 -- MONDAY, Aug. 11 (HealthDay News) -- About half of all American adults don't have the 20/20 vision physicians consider optimal because they are nearsighted, farsighted, or have an irregular corneal curve known as astigmatism, a large, new study reports.

The study revealed that such common eye-focus problems -- collectively known as "refractive errors"-- affect young, middle-aged and older adults of all races. Corrective care for such problems amounts to an estimated $3.8 billion to $7.2 billion annually, the researchers said.

"I think this study demonstrates that the problem of refractive eyesight errors is on the increase, particularly in terms of the amount of nearsightedness in the American population," said study co-author Dr. Frederick L. Ferris III, clinical director of the U.S. National Eye Institute.

"This is probably a worldwide problem," he added. "No one knows for sure what accounts for this. But it's a pretty smart hypothesis that the increased amount of near work that we're doing as a population may be increasing the incidence of nearsightedness. And it does suggest that we should be looking into ways to deal with it."

Rando Allikmets, a professor of ophthalmology, pathology and cell biology at Columbia University, said, "I would hazard to suggest that, in general, the widespread prevalence of refractive issues today could be related to environmental factors, like extensive use of TV and computers, and -- among the young -- video games. Because today we get much heavier loads on our eyes from all of that, and those are strenuous activities for our vision."

To take a current snapshot of American eye health, the study authors, led by Susan Vitale of the U.S. National Eye Institute, analyzed data collected by the U.S. Centers for Disease Control and Prevention's ongoing National Health and Nutrition Examination Survey. The survey, conducted between 1999 and 2004, involved more than 12,000 men and women 20 or older.

The authors found that 3.6 percent of those surveyed were farsighted, while about one-third were nearsighted. Slightly more than 36 percent were found to have some form of astigmatism.