The retinal implant or artificial retina has the purpose to “replace” the dead retinal photoreceptors and restore vision. Schematically, a retinal implant consists of a grid of micro-electrodes (artificial photoreceptors) that are activated by light stimulation and give rise to a “light signal” that travels via the physiological optics to the visual cortex. In practice, the grid of microelectrodes replaces the dead retinal photoreceptors.
Retinal diseases, such as macular degeneration or retinitis pigmentosa, affect primarily the retinal photoreceptors. From the first implant in 2002 with just a dozen electrodes (Argus I retinal prosthesis), it is expected that the research of new retinal prostheses will grow exponentially with more and more artificial photoreceptors in the next decade. To date, the retinal implants are implanted only within strict protocols.
In 2002, the first retinal implant with 16 electrodes, made it possible for 6 people blind due to retinitis pigmentosa, to be able to see the light. In the near future, implants with increasing number of electrodes will certainly be beneficial for thousands of blind people. Currently it is on going the study and development of new retinal prosthesis with 60 electrodes: the study is conducted entirely in Europe.