I need reading glasses and when shooting with iron sites it's all just a blur. I get it on target, just a bigger spread.. I do have a dot on mine (which is the way to go), but when I use my wife's gun, she only has sites. I've been working on my point and shoot both eyes open between 5 - 7 yards (no sites or dot), trying to keep the grouping as tight as I can on center mass. When I'm comfortable with the grouping I'll will move it out to 10 yards and so on.. Funny thing is, I'm better with strong hand only point and shoot.
I do have bifocals I use at the range, when I want to use sites over the green dot. At some point might look at lasix, but not sure if it is worth the hassle. Plus I heard that can sometimes cause other issues (dry and scratchy eyes).