Another insane property is a type of blindsight in people who are cortically blind, i.e., their eyes are intact, but have damage to the visual cortex so they cannot form or process images.
However, parts of our visual system other than forming images are handled in other parts of the brain. For example, managing the tracking of objects by the eye - it's a completely separate group of control neurons (vs the visual cortex) that drives where the eye looks (and it's actually different for vertical vs horizontal tracking).
So, it turns out that if you present images with, say, vertical or horizontal stripes and ask a person with cortical blindness (developed after they could see) person which it is, they'll tell you of course that they can't see & don't know. However, make it a forced-choice question where they must guess one or the other, and they'll get a high percentage right, far greater than chance. The information is exfiltrating from the centers controlling the eye motion even though there is no cortex to form an image.
However, parts of our visual system other than forming images are handled in other parts of the brain. For example, managing the tracking of objects by the eye - it's a completely separate group of control neurons (vs the visual cortex) that drives where the eye looks (and it's actually different for vertical vs horizontal tracking).
So, it turns out that if you present images with, say, vertical or horizontal stripes and ask a person with cortical blindness (developed after they could see) person which it is, they'll tell you of course that they can't see & don't know. However, make it a forced-choice question where they must guess one or the other, and they'll get a high percentage right, far greater than chance. The information is exfiltrating from the centers controlling the eye motion even though there is no cortex to form an image.