We studied the incidence of blindness and visual impairment in patients who were enrolled in a photographic control- and screening program for diabetic retinopathy. The study cohort consisted of 2133 patients examined between January 1990 and December 1992 and followed until October 1st 1995. The occurrence of blindness (visual acuity or = 8.5%, were associated with a 65% increase in risk of blindness/visual impairment (95% confidence interval 14-130%). Retinopathy was the major cause of blindness and visual impairment in patients with diabetes. The study revealed a low incidence of blindness, which is in line with recent reports. Control of hyperglycaemia may be of value for the prevention of visual loss.