Feature Tech

The Seeing Tongue

In-the-mouth electrodes give blind people a feel for vision

By Peter Weiss

- More than 2 years ago

Blind since birth, Marie-Laure Martin had always thought that candle flames were big balls of fire. The 39-year-old woman couldn’t see the flames themselves, but she could sense the candle’s aura of heat.

At the end of a flexible cable pressed against the tongue, an array of dotlike metal electrodes (below) stimulates touch-sensitive nerves with electric pulses.