I appreciate your posts, WS. But I can't agree with the statement:
"Healthy people do not get cataracts". Yes they do get them, and they get them just as bad as anyone else. That is because the eye lens proteins are almost never replaced, they are the same as the ones you were born with. Those proteins are easily damaged by UV or other forms of radiation coming into the eye, and they cannot be replaced. Other proteins in the body can be replaced.
I will agree with the fact that the liver has "some control" over the eyes by producing enzymes that can decompose some AGEs which would otherwise cause more damage to the eye lens. But it is difficult to undo eye damage through the liver alone. Local light treatment to the eye, or eye drops, are also needed.
As regards herbal eye drops that sting. Stinging is a marker of irritation. I have nothing against herbal eye drops, but I would prefer ones that do not sting.