The BrainPort vision device is an investigational, non-surgical visual prosthetic that translates information from a digit al video camera to the user's tongue, using gentle electrical stimulation. With training, totally blind users learn to interpret the images on their tongue as information about the scene in front of them.
The BrainPort vision system consists of a postage-stamp–sized array of 400 electrodes placed on the top surface of the tongue.
The brain almost immediately processes electrical impulses as images. But the images are grainy; learning to use them takes practice. After 25 hours of training, test subjects have been able to differentiate objects, like a mug from a Magic Marker, with 80% accuracy; read individual words on flash cards; and navigate a 15-foot hallway.