We examined 25 patients from three pedigrees with dominant optic atrophy (Kjer type). Follow-up on 20 patients ranged from five to 40 years (mean, 16 years; median, 13 years). Visual acuity ranged from 20/20 (in one 58-year-old man with an affected father and three affected children) to 20/400. The median initial visual acuity was 20/60, and the median final visual acuity was 20/80. Visual acuity remained unchanged or decreased by one Snellen line in both eyes of 13 patients (65%); it decreased between two and four Snellen lines in only one eye in three patients (15%) and in both eyes in four patients (20%). The rate of visual loss was unrelated to initial visual acuity or the particular pedigree to which the patient belonged. There was functional and ophthalmoscopic heterogeneity between and within the pedigrees. Eight patients perceived moderate to severe social or occupational handicap. Visual prognosis is relatively good in Kjer's dominant optic atrophy with stable or slow progression of visual loss.