I played without glasses for the longest time and felt I was doing fine. Once I finally played with glasses, I couldn't make the longer shots where I was looking over the rim, but for those that I was looking through my glasses? Amazing how much more accurate I became. Not just the potting, but moreso the shape - hitting the exact spot I want instead of close to it made a world of difference. I got laser surgery a few months ago and even better now - no worries about looking over the rim on the long shots
All that to say - yes, deteriorating eyesight will most definitely impact one's ability at a certain level.