The Argus II optical prosthetic, which is used to treat those with late stage retinitis pigmentosa, has been approved for use in Europe since 2011. The system consists of two parts, the first being a glasses setup that has a camera and a video processing unit attached to it, as well as an antenna that transmits video data to the second part of the prosthetic.
The second part of the Argus II is internal, consisting of an electrode array, antenna and electronics case that is surgically implanted into the eye. Retinitis pigmentosa sufferers eventually lose their eyesight when light-sensing photoreceptors in the eye stop functioning and the implanted electrode array is able to restore a semblance of sight for these people.
Video data from the glasses-mounted camera is sent to the video processing unit, where it is converted into information that the implanted electrodes can use. This information is transmitted wirelessly to the implant via the antenna on the glasses and the implanted electrodes transmit “…visual information along the optic nerve to the brain, creating the perception of patterns of light.” It isn’t exactly the same as getting one’s sight back but Second Sight says that patients learn to adapt to the unconventional, low-resolution, form of sight.