Should you spell it out?

Daniel Taverne, a blind disabled veteran from Louisiana, wrote this article about his experiences making a long bus trip. He has some useful tips for the traveler and carriers. (He's also a poet and a blogger.)
One of Taverne's tips, I admit, made me uncomfortable at first. He suggested the visually disabled pin a sign to their clothing that says "visually disabled" or something like that. This, Taverne suggests, would cut down on some of the trouble he experienced, such as when a food service employees asked can't you read the menu? He related that his red and white cane apparently often was not enough of a cue.
I admit the suggestion initially struck me as kind of degrading. Much of my own approach to traveling with a person who uses a wheelchair is to assume that he is entitled to all that others are and I shouldn't have to go around explaining or asking. But then I thought, well you know a wheelchair is a very obvious sign of disability. Someone whose main disability is visual, might not give off the same cues. In a more ideal world, I guess you hope someone wouldn't think it was such a big deal to relate a little info from a menu to someone who asks. But that's not reality.
In the end I bow to that other fall back truth about travel for those with disabilities: Whatever works.
Comment on your take.