I'm 67 so tell me about getting older. I used to be able to put 4 out of 5 in a quarter sized spot at 15 yards. Now I'm happy to get them in the size of a fist. Still.....it's good enough. I think this helps with the shakes and keeps my range time enjoyable instead of frustrating. I also take my time at the range...I've got plenty of that at least. I practice double or triple taps...then lower my weapon and repeat until the mag is empty. Then I take a break sitting down while I change mags or doing whatever. At the end of my session I do a mag change or two.....just to keep in practice.
As far as eyesight....well I can't read crapola or do anything close up without my bifocals so I get it. But over the past few years I shoot with both eyes open and focus on the front sight through to the target.....it seems to work for me.
So...good glasses, take your time and if you're not doing something for hand strength already you might want to consider it. I work with my hands every day so at least they still seem to work okay. Good luck and don't get frustrated.