It's rare, but I've seen singers with notes. I've seen Michael Stipe with a music stand with lyric sheets. Although R.E.M. is probably one of the few rock bands that could get away with their singer sitting on a stool and reading lyrics. Nick Cave has a guy with stack of cue cards for the 15 minutes of constant lyrics in "Babe, I'm On Fire."

But of course...there is the issue of your blindness...