When I first read the thread title I though you were making fun of visually impaired people but I now understand what you mean. It really would depend if they were blind from birth or not but really I don't think they would be able to dream if they were blind from birth. However I wouldn't rule out that they could possible hear things and feel as they slept as a form of dreaming because essentially that is what they recieve mostly while they are awake. I would be interested to hear how a blind person would describe dreaming.