JoeG, this is how I cope.
I need reading glasses, I get them cheap from Sam's Club. They come in magnifications of 1.0 to 3.0 perhaps more. I currently use 2.5 and are "small framed" wear them at the end of my nose mostly.
Can't transition from looking at the target then the sights then the target again without everything blurring.
The solution was "full frame" reading glasses at a factor of 1.0. This is enough for me to see the sights and still see the target clear enough (at least out to 75 feet). I use "full frame" glasses worn at the top of the nose as it provides more "protection" (these are not shooting glasses) for my eyes. I also have attached plastic side panels (the range sells them) to them.
Works for me.