Although I haven't taken any herbs for eyesight, I can vouch that herbs in general are pretty good at what they do. As a child and when I occasionally visit my grandmother in Mexico, they would give me herbal treatments for my asthma and stomach aches. I wish I kept the recipes. Although not an herb, my father takes shark oil to help his COPD. With a good, stable supply, he can go months and months without taking is Advair and Singular.
Also, when I was a student at TWU in Denton, Tx, I used to smoke a special blend to help me study. Maybe it was a placebo effect, but I did get a pretty darn good GPA.