I am not blind, but I do occasionally get migraines with visual auras, as do my wife & mother. Exactly once in my life that I recall, I had a migraine that caused total perceptual blindness (oddly, this has also happened exactly once to my wife, before we knew each other). It's extremely odd- one's visual field (at least in our cases) steadily contracts, until there's just nothing left. It's not an annulus of darkness closing in, it's juts nothing- the field you can see is smaller, and there's still nothing outside of it, just like there always isn't. Like what the back of your head looks like, as the article says.
In the end, you literally see Nothing. It's truly bizarre[1]. It's not an experience I particularly want to repeat, but I'm kinda glad it happened just once, for the empathy value. It's not really something that can be effectively described if you haven't (not) seen it yourself; even now, I have trouble re-imagining the experience, 'cause my memory wants to fill in blackness or grayness or whatever. But at least in theory I now know exactly what the Nothing from _The Neverending Story_ (doesn't) look(s) like. :)
[1] What makes it even more bizarre is that migraine blindness is a strictly neurological effect- there's no damage to your eyes or optic nerves- which means you can get temporary blindsight. In my wife's case, this meant she managed to walk a couple blocks home from a friend's house, crossing suburban streets and so forth, totally normally, while all the while convinced that she was completely blind. Which, as far as conscious perception goes, was the truth!
In the end, you literally see Nothing. It's truly bizarre[1]. It's not an experience I particularly want to repeat, but I'm kinda glad it happened just once, for the empathy value. It's not really something that can be effectively described if you haven't (not) seen it yourself; even now, I have trouble re-imagining the experience, 'cause my memory wants to fill in blackness or grayness or whatever. But at least in theory I now know exactly what the Nothing from _The Neverending Story_ (doesn't) look(s) like. :)
[1] What makes it even more bizarre is that migraine blindness is a strictly neurological effect- there's no damage to your eyes or optic nerves- which means you can get temporary blindsight. In my wife's case, this meant she managed to walk a couple blocks home from a friend's house, crossing suburban streets and so forth, totally normally, while all the while convinced that she was completely blind. Which, as far as conscious perception goes, was the truth!