Alright, so this game is more Breakout than Pong, but the idea of playing any paddle-based game with your eyes is pretty amazing.
Scientists in the U.K. are working on a computer interface to help people with multiple sclerosis and Parkinson's disease. The idea is that people without the usual range of motion/motor functions can use their eyes to control technology. Their first test is this amazing "Pong" game.
The glasses use a 3D camera to track how the subject's eyes move. Clearly, this should be included in the Google Glass project the moment they are available for general consumers.