49 but with bad eyes. I feel your pain!
For me...
1. Get good glasses with current prescription. Too many variables here depending on your eyes but work the glasses first.
2. Widen the rear slot to allow more daylight on either side of the post as others have said.
3. Get fiber optic front sight. It really helps even if it's not as precise. If you can't do that get the brightest orange model paint and touch up the front sight with it and that'll help too!
4. Manage your own expectations. In the military you shoult have seen what I could do with an M16 at 300 meters. You wouldn't believe me if I told you. I could get into the zone and have a zen like experience and shoot groops that made guys shake their head. But today.
well, I practice mostly defensive handgun skills at 7 yards
5. For rifles; get a good (and I mean good) scope but you still need the right glasses. for open sights on rifles, go with a peep rear and a fiber optic front. It helps old eyes!
6. Last and perhaps least, try a laser on your CCW guns.
And yes the alternative to growing old is worse!
God Bless
Gideon