Call it denial, if you will (although sitting in front of the puter with strong reading glasses is simply my reality - no denying that), but I think there are many good choices to be had in sights other than factory opens before one needs to concede the "need" for a scope on a lever. At 50, I certainly know what the loss of my youthful vision means. However, I have found, since I yet have good distance vision, that a rear peep has extended my ability to use "opens." I also know that the use of a second aperture on the front - a globe sight- can allow very functional use of iron sights for target work.
Handgun sights are another story. However, I have learned from them, even though my eyes and brain tell me that they are quite fuzzy, that, with practice, I can still use them in a functional and productive manner. I just need to practice more. Imagine that. I get - make that "need" - to do again, what I did as a youngster; get out and shoot more. It is less of an option than it was when my vision was better. And who said getting older has no benefits?