Individuals with impaired vision may be at increased risk of injuries and elderly persons are at increased risk of falls and fractures and depression, according to background information in the article. The most common reason for impaired vision may be refractive error, a condition usually correctable with eyeglasses or contact lenses. Refractive error is when the shape of the eye does not bend light correctly, resulting in a blurred image. The prevalence of visual impairment in the U.S. has not been surveyed nationally in several decades.
Susan Vitale, Ph.D., M.H.S., and colleagues with the National Eye Institute, National Institutes of Health, Bethesda, Md., conducted a study to estimate the number of U.S. individuals aged 12 years or older with impaired vision and the proportion of individuals who can achieve good distance vision with refractive correction. The researchers analyzed data from the National Health and Nutrition Examination Survey (NHANES), which included a vision evaluation in a mobile examination center for 13,265 participants in 1999-2002. Visual impairment was defined as presenting distance visual acuity (sharpness of vision) of 20/50 or worse in the better-seeing eye. Visual impairment due to uncorrected refractive error was defined as visual impairment that improved, aided by automated refraction, to 20/40 or better in the better-seeing eye.
Overall, 1,190 NHANES participants had with visual impairment (6.4 percent prevalence). The majority (83.3 percent) of these persons could achieve good corrected visual acuity (20/40 or better in the better-seeing eye) using autorefractor correction. Extrapolating the NHANES findings to the general U.S. population, approximately 14 million persons aged 12 years or older would be projected to have visual impairment. Of these individuals, more than 11 million could achieve good visual acuity with refractive correction.
The researchers also found that the prevalence of visual impairment was higher in persons who were of black, Hispanic, or other ethnicity, or who were poor, less educated, or lacked private health insurance. "Although these findings are not unexpected, they suggest that health care access and resources may be important barriers to consider in addressing the need for refractive correction of visual impairment."
"The provision of corrective lenses to those individuals in need will be an important public health endeavor with implications for safety and quality of life," the authors conclude.
(JAMA. 2006;295:2158-2163. Available pre-embargo to the media at www.jamamedia.org)
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