Thank you for this. I think I'm going to run with the macular degeneration, just 'cause it sounds closer, although I suppose it doesn't really matter other than "how fast do these things happen" -- I'm trying to figure out the time from Richard noticing something is wrong to Richard realizing it's probably not just him being tired to Richard realizing he has to say something to Alec about it.

Also, I remember that Katherine doesn't notice he's blind at first at all, and cataracts that are severe are visible, right?

As an aside though, I knew a girl when I was growing up who was born with cataracts and didn't have them removed until she was a few years old. In that time, here eyes started moving back and forth constanctly in an effort to see around the cataracts, and even after the surgery, they never stopped doing that.