One thing that often helps with older shooters is using a fiber-optic front sight. These stand out both brighter and sharper on targets and game.
I did this very thing last season. I traded for a Savage 99H in .303 in very good shape for a 92 yo rifle. While I could see the original front sight through the Lyman peep fairly well, I couldn't get a cheek weld because of the height. So I decided to get a lower front and while I was at it to get a FO sight too. I put the FO sight on first and low and behold it stood out and could be seen when it was almost dark. Now I can get a cheek weld and see clearly the front sight although I do pick up the receiver ring in the bottom of my sight picture.
