75 year old man with 2 months of sudden onset severe vision loss in both eyes. He had cataract surgery in the right eye one month ago and the vision was better but not good. He was on Ethambutol for 15 months ending 3 months ago for a lung infection. He has very poor color vision. VA 20/125 OD (post cataract surgery) 20/200 OS with dense cataract. He has temporal pallor of the optic nerve in both eyes.