The eye is going bionic, and companies are competing to develop the best technologies to restore vision to the blind, IEEE Spectrum Tech Talk reports.

The company Second Sight has just brought its retina implant to market in Europe, and is hoping for FDA approval in the U.S. this year.

Second Sight uses an external camera (mounted on a pair of sunglasses) to capture visual information, routes the info to a visual processing unit worn on a belt, and then sends the processed image to two antennae implanted around the eyes, where it’s forwarded on to a 60-electrode array that stimulates the remaining retinal cells.

German company Retina Implant AG, which has an implant currently undergoing clinical trials in Europe and the U.S., has taken a different approach. Instead of an external camera, they built a camera into the eye itself, using an implant that contains an array of 1500 photodiodes with amplifiers and electrodes. The photodiodes convert light signals into electric signals, which attached electrodes send via the optic nerve to the brain.