I'm 74 now and have used either cheaters or prescription glasses since I was 50. I flew for the airlines for my career and the problem with any glasses is that there are 3 areas I needed in focus: the instrument panel (roughly the same distance as the front sight on a 6" revolver with a Weaver, two-handed hold), the overhead panel with switches, gages et. all., and the maps and printed approach plates, which are carried off to one side on the ledge of the side windows.
The answer for me was progressive lenses...with the correction ground in a bit higher than most non-pilots like it. This same correction/focusing grind works equally well for computer work, but does take some getting used to. In use, with handguns, I need to tilt my head very slightly, to the rear, allowing the front sight to come into sharp focus. This slight tilt of the head is automatic and will come for you after a week or two. I don't even realize I'm doing it anymore.
For rifle use, the same works fairly well but doesn't allow a full cheek weld as one previous poster pointed out. In my case, my vision hasn't been so bad to need tri-focals, where the extreme upper part of the lens is ground for close in vision....seems like this would be a major pain in the patoot.
I still shoot iron sights with most of my lever guns, and have found that a receiver or tang mounted peep sight gives me good clarity with the front sight. The peep allowing both the target and front sight to be in focus at the same time due to its increased depth of field effect.
Lastly, for the first few years of flying after my eyes went south, I used Walmart cheaters: 1.25 then later1.5x sizes with complete success, both in shooting as well as in the cockpit. For shooting I used the larger diameter lens sizes to give my eyes some add'l protection in case of a punctured primer, but for flying, I used the half size, "granny" glasses, letting them slide down my nose to allow distance vision through the front acft windows. I can still use just cheaters for shooting handguns, but generally just keep my regular prescription glasses on as I have a correction for both near and far vision.
In my 60's I was still shooting NRA Hi-Power with a tuned AR-15 out to 600 yds, and found that 1.5x cheaters still allowed me to shoot to my ability to hold. The rear peep giving me just enough target clarity for a good, 6 o'clock hold on the bull. In my case, the 1.25x size was the limit on this type of long range sighting. I now need 1.75x and haven't tried to shoot over the course in over ten years and doubt that I'd be successful...hell, just getting down into prone (and getting back up!) for those 20 shots slow fire would be a challenge.
Were I you, I'd try the cheaters for awhile. Their correction, the smallest that you can get away with to bring the front sight into focus, forces you to concentrate on the front sight. You can check this at the store without bringing your pistolas in by pointing with your index finger extended and concentrating til you can see the nail in complete focus. You'll look a bit odd, but then most folks in our Walmart do too...especially on Friday nights.
Best regards, HTH's Rod