Seeing with Your Tongue.

The BrainPort consists of two parts: the band on his brow supports a tiny video camera; connected to this by a cable is a postage-stamp-size white plastic lollipop, which he holds in his mouth. The camera feed is reduced in resolution to a grid of four hundred gray-scale pixels, transmitted to his tongue via a corresponding grid of four hundred tiny electrodes on the lollipop. Dark pixels provide a strong shock; lighter pixels merely tingle. The resulting vision is a sensation that Weihenmayer describes as “pictures being painted with tiny bubbles.”