A few years ago my math teacher told me about his son who had cancer. The cancer somehow damaged his left eye and the eye had to be removed or it would start sp

A few years ago my math teacher told me about his son who had cancer. The cancer somehow damaged his left eye and the eye had to be removed or it would start spreading. So my math teacher took the heartbreaking decision to remove his son's left eye(His son was too young to decide for himself). A few years later, they discovered another malignant tumor in his right eye, so the teacher again took the decision to remove his right eye. Now you could imagine how horrible this must have been for both of them, but his son didn't give up and several years later he created a computer (or was it software?) designed for blind people. Not only did he get rich, but he also helped a lot of blind people.