Audio and Visual Prosthetics

Audio Prosthetics, such as cochlear implants (aka the Bionic Ear), are currently the most successful. This implant works by directly stimulating audiotry nerves.



As for Visual Prosthetics...

You know those tiny little dots you see after rubbing your eyes?

Those dots are actually phosphenes (a chemical which originates in the brain and is responsive to electrocortical stimulation). Scientist hope to stimulate patterns of phosophens which can then be interpreted by the 'user.' This would be achieved by implanting electrodes into the visual cortex of the brain. Progress is slow though, patients can see simple light patterns and make out crude letters. Such prosthetics include up to 100 microelectrodes permanently implanted in the visual cortex along with other external signal processing micro-electronics.