From Star Trek: Acronym for Visual Instrument and Sensory Organ Replacement.

A remarkable piece of bioelectronic engineering that allowed Geordi La Forge to see, despite the fact that he was born blind. A slim deviece worn over the face like a pair of sunglasses, the VISOR permitted vision in not only vision in not only visible light, but across much of the electromagnetic spectrum including infrared and radio waves.The VISOR, while giving La Forge better-than-normal sight, also caused him continuous pain.