Clear artificial vision is here

Just in time for Christmas drinking!

A team of Stanford boffins have worked out how to build eye implants that provide higher resolution and make artificial vision more natural.

Ophthalmology Associate Professor Daniel Palanker, electrical engineering Assistant Professor Peter Peumans and neurobiology Assistant Professor Stephen Baccus of Stanford, and biophysics Assistant Professor Alexander Sher of the University of California-Santa Cruz, have built retinal implants which can help the blind to see.

According to their report, the implants are arrays of electrodes, placed at the back of the eye, which partially restore vision to people with diseases that cause their light-sensing photoreceptors to die.

Normally they work by having a camera embedded in glasses collects visual information and sends it to a computer that converts the images to electrical signals, which are then transmitted to the implant and interpreted by the brain.

The problem with current technology is that most people with implants can only make out fuzzy borders between light and dark areas. This is because they only have 60 electrodes. However the Stanford implant which has 1,000 electrodes allows patients to make out the shape of objects and see meaningful images.

Currently to see anything patients have to move their heads to see as images fade when they do not move our eyes. The Stanford implant, on the other hand, retains the natural link between eye movements and vision, Palanker said.

The system involves a patient wearing a video camera that transmits images to a processor, which displays the images on an LCD screen on the inside of patient's goggles.

The LCD display transmits infrared light pulses that project the image to photovoltaic cells implanted underneath the retina. The photovoltaic cells convert light signals into electrical impulses that in turn stimulate retinal neurons above them.