I had a great-uncle Larry (90+) who was legally blind and was one of the funniest people I've ever known (I've written about his exploits of driving his gas-powered golf cart into supermarkets and purposely running into displays, then yelling "Sorry...I'm blind!"
He could read Braille, so one time I asked him to feel a stucco wall (one of those old kind with a zillion little pin points sticking out) and tell me what he could read. He thought that was hilarious and would play that joke on people while he waited in a line somewhere, with his blind assist cane. He'd feel the wall line by line, and then say something like "Hey, look, right here...President Lincoln spelled "emancipation" wrong."
It was great. People didn't know what to think.
Maybe he suggested Braille at the drive-thru ATM? Sound like something he'd do, with a completely straight face. God, I miss him.