Helping the blind see (device nearing end of clinical trials):
I have always wondered, what if a device were invented that could input visual stimuli and multiplex it into appropriate signals and feed this as input into the optic nerve of a blind person? After the signals travel down their visual pathways into the visual areas of the brain would the blind person start to 'see'?
Well, it turns out that a company in Europe is nearing the end of clinical trials into exactly such a device (albeit a simpler version) and would be applying for licenses to commercially sell such a device in the market in early 2008.

The company is Intelligent Medical Implants AG, based in Zug, Switzerland--with its subsidiaries IIP-Technologies GmbH and Intelligent Medical Implants Ltd. (collectively referred to as "IMI Group") and is developing the Learning Retinal Implant System(TM), the first product of its developing neuro-prosthetics technology platform.

About the Learning Retinal Implant System(TM)

IMI's Learning Retinal Implant System(TM) replaces the signal-processing functions of a healthy retina and provides input to the retinal nerve cells (the ganglion cells) that, in turn, provide input to the optic nerve and the brain. The System comprises three main components: (1) an implant, "The Retinal Stimulator", which is surgically placed into the eye of a patient, who wears (2) a pair of spectacles containing an integrated mini-camera and transmitter components for wireless signal and energy transmission ("The Visual Interface"). Via a cable, the spectacles are connected to (3) "The Pocket Processor" worn at the patient's waist. This device replaces the information processing function of the formally healthy retina. The use of a high-speed digital signal processor allows the provision of "intelligent information" to the implant (and the nerve cells) by using tuneable software to approximate the information processing normally carried out by the healthy retina. The entire process enables patients to optimize their visual perception during the learning phase. Indeed, using the patient's feedback on perception as an input for the tuning of The Pocket Processor is the unique, patent-protected feature of the System and constitutes the 'learning' capability of the Learning Retinal Implant System(TM).

"The provoked visual perceptions were pleasant, according to the patients, and this was the first time they had seen something in many years-- in one case, several decades. Understandably, they reacted emotionally to their visual experience."
Looks like the Science magazine had a report on this some time back.