Special glasses that fire near-infrared signals onto a device implanted into the retina could one day help to restore vision in blind people. This system would require fewer implanted components such as wires and coils to power the device than other proposed retinal prostheses.

James Loudin at Stanford University in California and his colleagues designed arrays of photovoltaic diodes (pictured) that can be inserted into the retina and used to stimulate inner retinal cells. The diodes could ultimately form part of a system whereby a video camera attached to glasses would gather and feed image data to a small portable computer, which would then convert the data into near-infrared light pulses. The glasses would beam those pulses through the eye onto the implanted diodes. This light would deliver both visual information and power to the diodes.

The researchers showed that the photodiode array could activate cells in both healthy and degenerating rat retinas in vitro when pulsed with near-infrared light.

Nature Photon. http://dx.doi.org/10.1038/nphoton.2012.104 (2012)