On: Blind man shocks researchers with what he sees.

[boyter]

If you want more information about this Through The Wormhole Season 2 Episode 5 "Is there a sixth sense" explored this and presented some theories on how it occurs. https://en.wikipedia.org/wiki/Through_the_Wormhole#Season_2

The show is excellent and presents a lot of science topics in and interesting and understandable way. Highly suggested viewing.