Not just necessarily just an old age concern, I suppose younger folks might suffer from these too (I'm 63). Anyway...I discovered exactly how goofy my vision is. I got lasik in 2000 and have been pretty happy with it. I ended up with a distance eye and a close eye--we didn't intentionally try for this in the surgery although some folks desire it. I'd always had one eye that was better at distance anyway.
Recently, I was trying to zero my Glocks with Holosun 407Cs with both eyes open, as I shoot that way. I was attempting a 15 yard zero (I'd only zero'd to 10 yards previously) and it was tough at 15--10 had even been tough in the past. I then tried using only my dominant right eye but it's my close distance eye and it has astigmatism--still frustrating to get a good group at 15 yards. After wasting a bunch of ammo and time, on a whim I thought I'd try only my left eye (my long distance eye). Voila! Sharp dot on a sharp bullseye and got my optics zeroed!! However, it felt really weird to shift my head to the right so I could use the left eye. This all said, I'll still shoot defensive pistol with both eyes open but for range fun/distance marksmanship with pistol and rifle, I'll try my left eye only.
What eye issues have you had to address? How did you overcome them?