Self-powered retinal implants are reported online in Nature Photonics this week. The work, which was performed on rats, has the potential to help scientists to restore vision in blind humans using fewer implanted components, such as wires and coils for power supply, than previous related prosthesis devices.

Current retinal prostheses - which have been shown to restore certain levels of vision in blind individuals - are typically powered by inductive coils, and therefore require complex surgical procedures to implant the necessary components. James Loudin and colleagues have developed self-powered retinal prostheses by fitting each pixel in their device with silicon photodiodes. Goggles worn by the individual emit near-infrared pulses that transmit both power and data directly to the photodiodes. The team demonstrate the plausibility of this design through successful in vitro electrical stimulation of healthy and degenerate rat retina by photodiodes powered by near-infrared light.

The pulses used in the work do not exceed ocular safety limits, which suggests that this technique may be safely for use in humans