In fact, our vision is so biased toward movement that we don’t technically see stationary objects at all. To see something stationary, our brains have to scribble our eyes very subtly over its surface. Experiments have even proved that if you artificially stabilize an image on the retina with a combination of special contact lenses and microelectronics, the image will vanish.

When microprocessors got small enough, Bach-y-Rita built devices to stimulate the tongue, one of the body’s most sensitive tactile areas. [..] The scans revealed that, even though the video information came streaming in through the tongue, the brain’s vision centers crackled with activity. Neurologically, this input was indistinguishable from “sight.” […] They even fell prey to certain optical illusions, like the “waterfall effect". If you stare at something in motion (like a waterfall) for several seconds and then look away, whatever you focus on next seems to move of its own accord. Bach-y-Rita’s device induces this same vertiginous feeling in blind people […].