The 85 Combat comes with adjustable three dot sights.
And the difference in sight radius isn't likely to be much help.
When your eyes start to go, the only solution is glasses, and WATCH THE FRONT SIGHT!! (I'm 58, and am speaking from experience...)
You'll hear this again and again. You don't really need to see the target all that clearly; you need to see the front sight clearly!
You can try to find different sights for your gun -- even going so far as to have something like a Bomar sight installed. (It would require a different dovetail cut, but any gunsmith can do that...)
CDNN had other types of sights on hand recently at very reasonable prices (including the standard target sights, a white outline, and the dot sights); the target kits had a matching front sight.
www.cdnninvestments.co