Recent epidemiological studies of mental retardation were critically reviewed, and data on prevalence, associated disorders, and etiology examined. Results indicated that there was a prevalence for both severe and mild retardation of 3 to 4 per 1000, that a wide range of disorders were associated with mental retardation, and that etiology is often…

This article presents the findings of the most comprehensive Canadian survey on disabilities, the 1986 postcensus Health and Activity Limitation Survey, which analyzed data on blindness and visual impairment. New information on prevalence rates, age at onset, cause of visual loss, and severity of visual impairment is presented. (Author/DB)