http://www.amazon.com/Physiology-Behavior-MyPsychKit-Neil-Carlson/dp/0205593895/ref=pd_bbs_sr_1?ie=UTF8&s=books&qid=1230187013&sr=8-1
Chapter 1 has a short item on blindsight and it's relation to consciousness. You should really read chapter 1 of this book.
IMHO, sight doesn't happen as much in the eyes as it does in the brain.
Well, that's how the brain does its thing. Your eyes, ears, nose, skin, are instruments that extend from the brain. Data that flows from your senses to your brain lacks meaning until the brain processes it.
A few posts earlier you say:
( http://science.slashdot.org/comments.pl?sid=1072951&cid=26228425 )
Without a working visual cortex, nothing from the eyes enters the brain. At all.
Blindsight does not imply that the visual cortex does not "work". Have a look at http://en.wikipedia.org/wiki/Primary_visual_cortex
Data still flows from the eyes over the optical chiasm to the primary visual cortex (the cortex around the calcarine fissure in the occipital lobe). From there, there are multiple "streams" of visual data. One of those streams is the one that "enters" consciousness.
It is the absolute certainty with which you refute the previous, and the postulation of the following near-superhuman senses that make you appear rather uninformed and quite arrogant.
Most likely, he is using sound or air pressure. Blind people can often maneuver by hearing things like subtle changes in sound of footprints, etc., echoing off of or being aborbed by walls, etc. There are also subtle changes in air pressure as you approach obstacles, and that can often be 'felt' by blind people.
Take a biological psychology course or your own medicine (your signature)
http://www.scholarpedia.org/article/Blindsight
http://en.wikipedia.org/wiki/Blindsight