A New Vision for Restoring Sight

Photo: Elizabeth Murdoch Titcomb

Researchers at Stanford are developing a type of retinal prosthesis that, unlike other models currently in clinical trials, does not require coils, cables or antennas inside the eye to deliver power and data to the device. Instead, special video goggles deliver near-infrared pulses to a small, thin photovoltaic chip implanted beneath the retina that converts light into electrical current that both powers the device and transmits visual information. The system, conceived and designed by Daniel Palanker, an associate professor of ophthalmology, and James Loudin, PhD '10, a postdoctoral researcher, could one day restore sight to individuals with retinal degenerative diseases. In conditions such as macular degeneration and retinitis pigmentosa—the leading causes of age-related and inherited blindness, respectively—visual impairment is due to the loss of "image capturing" cells; the "image processing" apparatus remains more or less intact. Retinal prostheses are designed to stand in for the compromised photoreceptors and stimulate the surviving cells, which in turn transmit signals to the visual areas of the brain.