Somewhat related to the subject at hand...
Robert Bruce (author of Astral Dynamics) developed his Tactile Imaging technique for energy work and astral projection in an effort to train blind persons to induce OBEs.
Link(Scroll down to the section titled "Tactile Imaging")
Apparently it has worked for some folks, there's an interview online somewhere where a blind person talks about what it's like to dream and go OBE.
The moral of the story seems to be... being blind or deaf isn't necessarily a hindrance when it comes to spiritual practice.