My eyes are certainly not what they once were (memory isnt what I remember it being either
), bifocals, astigmatism, floaters, etc. so I know what you mean. Peeps work fairly well now, though the rear hole appears egg shaped, not round, and I can still score reasonably good. The oft repeated 30% better groups with peep than open sights is as good a guess as any. But when I really want to see (pun intended) what the rifle or ammo is capable of, I use a scope. I have a few that I put scopes on intending to 'work 'em out' and then switch to iron sights, but the scopes have stayed on. I think that once you settle on a scope/ring/height combo you like that you will be pleased.
Remember, if you cant see it, you cant hit it!