There are a lot of good scopes to chose from, some fairly low priced on that are hard to tell from the expensive ones anymore. So your budget and what you are willing to spend enters into it big time, The first thing I would warn against if you dont already know about it especally if you have not used scopes much is that to much power when your hunting is going to make it very hard to find your game, it also makes shooting offhand very difficult especally if you have always used iron sights.
It sounds like you have the same problem I do in that age has caused your eyes to loose the ability to focus at multiple ranges so you can see the target and the sights at the same time , any good scope will eliminate that, another problem one that some people dont realize usually goes with that and that is your ability to preceive light has lessened, the right scope can help that some to. In the specs of the scope they will call it lumes.
So what it boils down to is that you need to look for certain things, low power with a large front lens[ objective] will give you the lumes or light gathering power but remember it goes down as the power goes up and the smaller the objective lens the less you start with. One of the other important things is the eye relief in order to keep the recoil from slaming the scope into your eye or forhead I suggest at least 4 inches or real close to it.
A 1 to 2 power for hunting so you have quick target pick up a varable with aupper end of at least 4 power is nice for sighting in and a bit of fun shooting so a 1.5X 4 X 32 is very good I have a BushnellTrophy on two of my guns and a 2X7X40 Swift on the other that I shoot a lot I rate them excellant, I also have several others including a Nikon and a Lepold which are very good; the Nikon Omega has fixed yardage markers right in with the cross hair which only matches one load [250 Shock Wave with 150 gr Pyrodex pellets] which very few guns happened to shoot so I persoally would avoid that one.
I hope this helps. Lee