When you get to be my age, it can be difficult to do fine work on your firearms, especially at the range. If you are trying to move the sights, or clear a jam, it can be difficult to see up close without switching to your reading glasses (not a good idea where there is live shooting happening). Here is a solution that’s worked for me.
These safety glasses are Z87 rated and have built in bi-focal reader lenses.
You can shoot in them and then adjust your sights, etc., without changing glasses. I even used them when I did the DIY Night Sight Project. You can get them on Amazon here:
They also make a UV blocking tinted version for outdoors!
Both types have rubber grips at the end of the frame, so they don’t slide off during activity.by