The maker of the world’s first commercial artificial retina, which provides partial sight to people with a certain form of blindness, is launching a clinical trial for a brain implant designed to restore vision to more patients. The company, Second Sight, is testing whether an array of electrodes placed on the surface of the brain can return limited vision to people who have gone partially or completely blind.
Also known as a bionic eye, all three devices are intended to bring back some vision in patients with a genetic eye disorder called retinitis pigmentosa. The disease causes gradual vision loss when light-sensing cells called photoreceptors break down in the retina—the tissue membrane that coats the back of the eye.
The new device, the Orion, borrows about 90 percent of its technology from the Argus II but bypasses the eye. Instead, an array of electrodes is placed on the surface of the visual cortex, the part of the brain that processes visual information. Delivering electrical pulses here should tell the brain to perceive patterns of light.
A major downside is the device requires a more invasive surgery than the Argus II. A small section of the skull needs to be removed to expose the area of the brain where the array of electrodes is placed. Because electrical brain implants carry risks like infection or seizures, the first clinical trial will be small, and the company will start off by testing the implant in patients who are completely blind.