I actually talked with an ophtho resident about this (since it requires such fine hand movements) and he told me that most ophtho's have "disability" insurance that guarentees them the same income if they are no longer to perform the delicate surgeries that they once were able to do. I don't think that disability insurance is the ultimate answer for this question, but it's part of it. Another part is going on to do other things as you get older. In the past, surgeons never had to worry about working to old age since they usually made enough to retire at a relatively young age. Now it's getting to be more of an issue with decreasing salaries and higher med school debt. Some surgeons end up doing things like general practice, some end up teaching or becoming administrators, and I even heard of one that became a drug rep (he became a drug rep at a young age though). Anyways, there are other things that you can do when you can no longer "cut".