This is for the old fellows: I'm 63. Always refused to use a scope on rifles. In recent months, I've found I cannot focus on open sights unless they are peep sights. My 45/70 Classic came with peeps that I replaced with a better version from Williams. When I first tied it, I was getting tight groups at 100 yards with Remington green box 405's. Then, almost suddenly, I realized I could not focus on the sights and target. Glasses on or off, I could not remove the fuzziness. Oh, no!
I went to the eye doc. He said I had a rapidly progressing cataract in my right eye; that a cloudy film had grown over my lens. I said, "Fix it!"
He did. The surgery was painless. A few weeks later I could see my sights AND the target better than I could remember ever seeing in my teens. My 100 yard targets appear crisp and clear.
My point is, if your vision is fading due to age, it CAN be fixed. I'm spotting groundhogs and license plates and pretty girls that I haven't been able to identify for years. As a bonus, colors are now much more vivid. I especially appreciate the greens and yellows that I had all but forgotten. If you eve suspect that your vision is not what is should be, get it checked. The remedy is so much easier than you might imagine.
Also, I'd like to add that I am an avid pistol/revolver shooter. The clarity of handgun sights is critical to success, as you know. Since getting my eye fixed, I can see the sights AND the target. If you think you might need help, ask for it. Be thankful for (and take advantage of) the techonology that helps us stay strong and efficient in the shooting sports.