A while ago, I started a thread talking about wizards with disabilities (Blindness, deafness, etc.). Some people argued that because of magic, there would not be very many wizards with disabilities. But then I thought back to Harry, James, and Dumbledore who all wear glasses in the series. If magic were capable of curing blindness, it seems that it could easily cure simple poor eyesight.
So I wonder, what are the limits magic has towards healing in terms of disability as well as other injuries and ailments?