Around the age of 38 my eyes started to act up, but I didn't notice.
Around the age of 42 I bowed to reality and decided to get bifocals.
I can't read comfortably now without 'cheaters' or bifocals, unless the font is around 20 point, at distances less than around 4 1/2 feet.
My need for bifocals/cheaters extends to about 4 1/2 feet, so all pistol front sights are not perfectly clear. My rifles are around the same.
I don't 'need' glasses to walk around, read signs, drive, etc. My mild astigmatism is helped, but I have close to 20/20 at 10+ feet.
It is the close up stuff.
In other words: I HEAR YOU!
What I chose to do was to think about how I would be using the firearm in a real-time situation.
If I am saving a life, I am grabbing the gun and using it.
I am not going to search for my cheaters or other glasses, on the other side of the house, at night, when someone is between me and them and threatening my wife.
So, I practice without glasses- and I do the best I can to line up the sights on the target, and 'focus' the most on the front sight. Unfortunately, everything is a bit blurry when I do this, but I am still getting <3" groups at 7 yards, when I do my part [.22 is closer to 1", .38, 9mm, .45acp, .40S&W, .357, 10mm, .44mag- all about the same size groups].
I have high confidence I can put lead where I need to and save a life.
As for rifle, it depends on which rifle. 'hunting' or 'precision/competition' rifles, I have no problem using my prescription glasses with the scopes I have installed.
With iron sights, I prefer to use no prescription.
I know my groups could be better, but it is a matter of 'training the way i'll need to use it'.