From the American Academy of Ophthalmology

Investigators determined the lifetime risk of low vision and blindness among a large sample of patients with open-angle glaucoma who were followed on average to less than one year before death. They found that 42.2 percent were blind from glaucoma in at least one eye at the last visit, and 16.4 percent were bilaterally blind, while just 0.5 percent had low vision. Blindness mostly occurred at late ages. Median duration of blindness was two years. With life expectancy increasing, it’s possible the lifetime risk of blindness may increase further. American Journal of Ophthalmology, October 2013