For folks that have vision problems during the swimming, Speedo offers 11 off-the-shelf prescription goggles. A couple of swimmers in my masters group use them and word is the googles work work great. If you don’t know what prescription level you need, some
stores will let you try on different goggles until you find one that works for you.
I had to share this nifty find for swimmers that have trouble seeing the board or the clock during workouts - or - have trouble sighting during a triathlon.