Light-Powered Retinal Implant

A new retinal prosthesis that uses infrared light as a power source may someday restore vision to millions of people with fewer complications and better outcomes than current devices.

In macular degeneration (the most common cause of blindness among older adults) the cells of the retina lose their ability to sense light, but the underlying nerves that convey information to the brain are often still intact.  Retinal implants use electrodes to stimulate those nerves, but typically require patients to wear bulky electronic hardware to supply power and image information to a chip inside the eye. In addition, pixel count is limited, resulting in poor image quality.

The new device contains an infrared projection system in the goggles which intensifies light and sends it to a wireless chip implanted in the retina. A flexible array of photovoltaic silicon pixels containing infrared-sensitive diodes converts the light into electrical signals to be picked up by the neurons in the eye. And because it uses infrared rather than visible light, there is no risk of damage to eye tissues or muddling of the image due to cells that may still be light-sensitive. Clinical trials are still a few years away.