I'm in the "over 50" bi focal group also. I had S&W performance center 9mm with a Trijicon dual illumination dot sight.
It had a 9moa dot. Two things I didn't like about the sight. One, the dot was to large beyond 25 yards. Two, I disliked the pinkish lens coating on that model. It sucked in low light and obscured the front sight. I did work well with my aging eyes as far as the red dot sight was considered. Fast and accurate. My next one will have a battery and a 3-5moa dot, with clear lens coatings.
