http://blogs.scientificamerican.com/obs ... nowing-it/
His eyes were perfect. The part of his brain that translated the signal from the eye to his conscious brain was damaged. Another part of the brain transmits the eye signal to the unconscious brain. That part was undamaged. He could not consciously see but he could unconsciously see. To say it another way, he could see enough to avoid obstacles but he didn't know that he could see.In 2003, a patient known as TN lost use of his primary visual cortex, area V1. He had two successive strokes, which knocked out the region in both his left and right hemisphere. After his strokes, ordinary tests of TN’s sight turned up nothing. He could not even detect large objects moving right in front of his eyes. Researchers eventually began to notice that TN exhibited signs of blindsight and in 2008 decided to test their theory. They took TN into a hallway and asked him to walk through it without using the cane he always carried after having the strokes. TN was not aware at the time, but the researchers had placed various obstacles in the hallway to test if he could avoid them without conscious use of his sight. To the researchers' delight, he moved around every obstacle with ease, at one point even pressing himself up against the wall to squeeze past a trashcan placed in his way. After navigating through the hallway, TN reported that he was just walking the way he wanted to, not because he knew anything was there.
Here's where it gets interesting. Those of us with normal brains cannot consciously see different images in each eye. This is know as binocular rivalry. The conscious-vision-translation portion of the brain cannot deal with conflicting images. It blocks one and sees the other. If one image is stagnant and the other is changing, the conscious brain - but not the unconscious - ignores the stagnant image and sees the motion in the other eye. The unconscious brain sees both images.
https://en.wikipedia.org/wiki/Motion-in ... uppression
There are a bunch of new studies showing that we are highly susceptible to priming by images shown to the eye that cannot consciously see. Show a photo of food and we become hungry but we don't know why. Show sexual images and we become aroused without knowing we saw anything arousing.
Google Glass shows an image to only one eye while the other is looking out at the constantly changing world.
Walk past Burger King and the photo of a Whopper gets fed directly to the unconscious mind without ever entering consciousness. Imagine the potential.
tl;dr Buy Google.