Cataract surgery restores sight to chimpanzee Pierre, 54

Pierre, a 54-year-old chimpanzee at Chimp Haven, the world's largest chimpanzee sanctuary, had gone completely blind due to cataracts. Caretakers spent months preparing him for surgery: through positive reinforcement, Pierre learned to voluntarily offer his eyes for care such as eye drops while still blind. Ophthalmologist Dr. Kenneth Pierce then performed the first cataract surgery ever on a Chimp Haven...