Eye problems and hand problems are different problems.
I have average sized hands. I tie down to #32. I use flies 24-26 regularly. It all comes down to how you use your tools. Thread control is huge. Understanding which thread to use for which bug, knowing how each thread behaves in different situations, things like that make a big difference. Bodkins are very useful for micro-manipulation and the application of cements. You can do things with the tip of a needle that just can't be done with the hand.
Repetition is the real key. You probably sucked at tying your shoes the first few times you did it. I know my mom had to beat me with a switch to loose the velcro when I was a kid, my knot tying was horrid. I now can tie a Bimini twist in four pound mono in about a minute. So practice a lot.
As far as the eyes go... My eyes were always bad, and have only got worse. I am super blind. I still have about a 10-14" range of near field vision without correction. I am not looking forward to magnifiers, I can tell you that. But the best setup I ever saw was a camcorder and video monitor system that Chad Schiel (another Rainy's contract tier) used for his demonstrations. Clear, crisp, and free of the headache-inducing optical distortions that seem to plague the common "magnifying glass" type apparatus.
Hope some of that is useful.
SS