Preventable Visual Loss

Abstract

Ten million or so Americans have some visual disability, of whom perhaps half a million are legally blind with corrected vision of less than 20/200 in each eye. Another million or so have visual impairment such that despite wearing glasses they cannot read a newspaper.¹ Precise data regarding the prevalence and cause of visual problems do not exist. To attempt to generate such data, between 1979 and 1983 the National Eye Institute performed a study to determine whether it could obtain “estimates of the prevalence, by cause, of visual acuity impairment in persons 25 years of age or older.”² The study concluded that such estimates could not be reliably obtained, largely because people were unwilling to be examined (P. F. Palmberg, personal communication).