Board Thread:Suggestions/@comment-5974425-20140625165904/@comment-4536066-20140628191927

There are real-world cases of people suffering from blindness who, though they are not actively able to see or sense things in the way that properly visual people can, can react to an object in the environment without touching it or examining it with an alternative sense. This is a phenomenon only seen in people whose actual eyes and optical organs are fine, but who are blind because something is wrong in the part of the visual process that controls a person's ability to actually perceive sight. It's called blindsight.

"Type 1 blindsight is the term given to this ability to guess—at levels significantly above chance—aspects of a visual stimulus (such as location or type of movement) without any conscious awareness of any stimuli. Type 2 blindsight occurs when patients claim to have a feeling that there has been a change within their blind area—e.g. movement—but that it was not a visual percept."