Most of my shooting is with traditional muzzle loaders. Almost all of our shooting is with open sights. What you describe is a problem with aging shooters. Part of what you describe can be tracked to fit of the rifle for you. Adding height to the comb might help. There are special shooting glasses but in prescription they are expensive. And, finding an optometrist or opthamologist who can fit properly can be difficult. You need one who is a shooter and understands the issue.
Part of the solution can be fixed with an eyeglass peep attachment. Like this one:
http://www.midwayusa.com/product/978...th-suction-cup
There are less expensive options on the market. You have to look for them.