In order to determine the risk for bilateral blindness from glaucoma and to which extent other diseases are responsible for the disability, the registers of low vision clinics were surveyed. All registered patients still alive in 1991 with the diagnosis of glaucoma were included. Eighteen hundred and ninety-five patients fulfilled these criteria. Blindness was defined as bilateral visual acuity < or = 0.1. The majority of the patients (68%) had a visual acuity better than 0.1. The remaining 590 patients had a visual acuity < or = 0.1. In this latter group glaucoma was the reason for the low visual acuity in 20%, glaucoma in combination with other eye diseases in 35% and other eye diseases in 44%. Macular degeneration and cataracts were the main causes of the low vision in the latter group. The prevalence of glaucoma blindness in the Stockholm region was found to be 0.007% for glaucoma and 0.020% for glaucoma in combination with other eye diseases.