I now need reading glasses. Not for everything, but for things like newspaper comics, the dictionary, etc. I know many will say what's the big deal- I've needed glasses all my life. And I would reply that it's not the glasses that bother me; I wouldn't mind them if I'd always needed them.
What weighs with me is that this is my body's first betrayal... the first scars not earned by injury or battle with nature's microscopic predators. The first confirmation that there are fewer days ahead than behind. In one's first half century, one is of course aware that death can lurk around any corner, but the dangers are usually the understandable and semi-predictable; a traffic accident, a flu epidemic, a mugger, or the foolish chances one takes when young. It is somehow a different thing to accept that you will eventually just spoil, like the carton of milk you forgot to put away.