In a startling demonstration that the brain isn't interested in a pixel-for-pixel representation of the world, but in a world, rather, that makes sense, a new device will soon be marketed that uses a small plate on the tongue to pass along electrical signals corresponding with light intensity to the brain. The sensation is described as feeling like pop rocks or champagne bubbles.
Researchers don't yet understand whether the signal is sent to the somatosensory cortex, where touch data from the tongue is interpreted, or the visual cortex.
No matter. Amazingly, trials have shown that wearer's can soon distinguish objects such as doorknobs, forks and letters, according to the Scientific American article "Tasting the Light." An estimated one million or so people in the United States are blind.