They said when you are nearsighted, the cornea is too round. So, they take pieces out to make it flatter. If you are farsighted the cornea is too flat and it is much harder to add curvature.
I have another friend that got RK surgery years ago. It corrected her nearsightedness. And now she had reading glasses for seeing things close, but normally doesn’t need glasses. Something like that is a possibility??
The consultation at TLC is free. They are very proud of their success rate. I don’t think they will perform the surgery unless there is a good probability of success. Have your dad go there and check it out. They can say for sure if they can correct his vision.