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. With an auto-refractor the researchers  obtained refractive error data on a sample of 12,010 US adults in the 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%).
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.