Bionic eye offers hope to the blind

Sandia National Laboratories have released a prototype "eye-chip" that may eventually achieve the miraculous goal of restoring sight to the blind. Part of an ambitious project involving several US national labs and Universities, the chip will be inserted onto the retina of a blind patient and linked to nerves that will send electrical impulses to the brain for processing. The module will receive data from a tiny camera lodged in the frame of the patient's glasses and the current MEMS [microelectromechanical systems] - based array aims to produce 1000 points of light (compared with millions in the biological eye) delivering a yellowish image that is slow to form but nonetheless a vast improvement on complete blindness.

The idea, funded by a $9 million, three-year grant from the US Department of Energy's Office of Biological and Environmental Research, will target blindness caused by diseases such as age-related macular degeneration and retinitis pigmentosa. These diseases damage rods and cones in the eye that normally convert light to electrical impulses, but leave intact the neural paths to the brain that transport electrical signals. Eventually the input from rods and cones ceases, but 70 to 90 percent of nerve structures set up to receive those inputs remain intact. Two hundred thousand eyes in the US are blinded each year by macular degeneration, primarily in the elderly. One baby in 4,000 demonstrates retinitis pigmentosa.

"The aim is to bring a blind person to the point where he or she can read, move around objects in the house, and do basic household chores," says Sandia project leader Kurt Wessendorf. "They won't be able to drive cars, at least in the near future, because instead of millions of pixels, they'll see approximately a thousand. The images will come a little slowly and appear yellow. But people who are blind will see."