One of the classes I took this semester made us read books on modern neuroscience. I remember reading cases of people who are blind due to a brain injury, but have working reflexs in the "blind" eye. For example, if someone were to pretend to punch them in a blind area, they would automatically reach out there arm and block it perfectly, without "seeing" a thing.
Vision in the brain is extremely complex, I don't remember the actual number, but there is something like 19 vision sections of the brain, each one has its own role. I believe vision as we know it only takes up a few of those sections.
To make it more complicated, apparently there are two vision pathways, one new, one old. (By new and old I'm referring to the relative time they developed in the human species, the "new" system has probably been in us for thousands of years) The new one allows us to do more advance processing on images, while the old is used for more reflexes, hence the example above where a blind person can see.
If anyone is interested in reading about modern neuroscience, I'd recommend V.S. Ramachandran's book, Phantoms in the Brain