our eyes allow us to detect a certain frequency of light being transmitted from any light source. The eyes focus on a miniscule part of the FULL spectrum of light... and anything outside that spectrum (about 90% of light frequencies) we cannot SEE....
so a blind persons' dreams may be more elusive and truly more real, because sight is actually a setback when learning about things in their pure forms (ie: how hard is it to explain the color blue, given you've seen it, it's all you recollect, but there is a way to explain the color blue without saying the word)