A new study has found that common vision problems known as refractive errors (nearsightedness, farsightedness, and astigmatism) affect half the adult U.S population.
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. In this study an autorefractor was used to obtain refractive error data on a nationally representative sample of 12,010 adults in the U.S. population between 1999 and 2004.
Of the participants (all aged 20 or older), researchers found:
- 3.6% had hyperopia (farsightedness),
- 33.1% had myopia (nearsightedness), and
- 36.1% had astigmatism (an irregular corneal curve)
Other findings:
- Nearsightedness was more prevalent in women (39.9%) than in men (32.6%) among 20- to 39-year-old participants.
- People 60 years or older were less likely to have nearsightedness and more likely to have farsightedness and/or astigmatism than younger persons.
- Nearsightedness was more common in non-Hispanic whites (35.2%) than in non-Hispanic blacks (28.6%) or Mexican Americans (25.1%).
“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.”
Read more about maintaining healthy vision naturally through nutrition, lifestyle adjustments and vitamins.
SOURCE: Susan Vitale, PhD, MHS; Leon Ellwein, PhD; Mary Frances Cotch, PhD; Frederick L. Ferris III, MD; Robert Sperduto, MD; Arch Ophthalmol. 2008;126(8):1111-1119.
A Chinese study finds that there is a relationship between the biomechanical properties of the cornea and the degree to which an individual suffers from myopia. Amongst their findings, researchers describe how highly myopic subjects were more likely to have decreased corneal hysteresis (CH). CH is a measure of viscous damping in the corneal tissue. The figure indicates the “energy absorption capability” of the cornea.
