Hawking talking with his blinks

Encouraging…Disabled scientist Professor Stephen Hawking is using a hi-tech gadget to communicate by blinking because his deteriorating health limits movement. The Infrared Sound Touch (IST) switch has been developed by the American company Words+ and works by emitting a very low-powered infrared beam. The reflection of the beam changes when the eye is closed and the cheek muscle moves and so controlling the computer is as simple as blinking. Link.