Our ancestors wore their bodies out early in age from all the work. Sometimes a documentary on a archaeology site will have a Paleontologist examining the bones (there is one on Vesuvius I can remember). When they find a whole skeleton they can determine the age, sex and amount of work they did. Usually the workers had arthritis or other joint damage.
I do all exercises in moderation of course. It is just important to move and not just sit around the whole day. Even if its just a little bit of exercise.
Regarding eyesight. A friend had great success with techniques described in this book. He practiced for about a year and does not wear glasses now and is doing fine. He still practices every day. I already bought the book and its in my reading queue but I didn’t have time to check it out yet.
Alea iacta est ("The die has been cast")