As for staying in the open sights game, with aging eyeballs, try wearing a pair of low magnification el-cheapo reading glasses. 1.00 or 1.25x is good. They will sharpen the sights sufficiently for precise aiming while at the same time not distorting the target so bad as to render it un-seeable.

"You can lead a man to logic, but you cannot make him think." Joe Harz
"Always certain, often right." Keith McCafferty