Purpose: To describe the prevalence of refractive errors in a population of adult Americans.
Methods: From 1988 to 1990, 4926 adults who were 43 to 84 years of age and living in Beaver Dam, Wisconsin at the time of the 1987-1988 census were examined. Refractions were performed according to a modification of the Early Treatment Diabetic Retinopathy Study protocol. Included in this study were 4533 people who had not undergone cataract surgery and who had a best corrected visual acuity better than 20/40 in at least one eye. Myopia was defined as a refractive error less than -0.50 diopters; hyperopia was defined as a refractive error greater than +0.50 diopters.
Results: Hyperopia was more frequent than myopia in the study group (age-adjusted of 49.0% and 26.2% in right eyes, respectively, P = 0.0001). The prevalence of hyperopia in the right eye increased with increasing age from 22.1% in those 43 to 54 years of age to 68.5% in those 75 years of age or older. The prevalence of myopia in the right eye decreased from 43.0% in those 43 to 54 years of age to 14.4% in those 75 years of age or older. There was significant relationship between education level and refractive error (age adjusted r = -0.32, P = 0.0001). Neither household income nor occupation was associated with refractive error in our data.
Conclusion: These cross-sectional data indicate age-related differences in refractive status in an adult population and suggest that education is associated with myopia independent of age.