Light-powered bionic eye invented to help restore sight

A retinal implant - or bionic eye - which is powered by light has been invented by scientists at Stanford University in California. Implants currently used in patients need to be powered by a battery.

The new device, described in the journal Nature Photonics, uses a special pair of glasses to beam near infrared light into the eye.

Retinal implants stimulate the nerves in the back of the eye, which has helped some patients to see. Early results of a trial in the UK mean two men have gone from being totally blind to being able to perceive light and even some shapes.

However, as well as a fitting a chip behind the retina, a battery needs to be fitted behind the ear and a cable needs to join the two together.

Prof Robert MacLaren from Oxford Eye Hospital explains how a bionic eye implant works
The Stanford researchers say their method could be a step forward by "eliminating the need for complex electronics and wiring".

A pair of glasses fitted with a video camera records what is happening before a patient's eyes and fires beams of near infrared light on to the retinal chip. This creates an electrical signal which is passed on to nerves. Natural light is 1,000 times too weak to power the implant.

Source: http://www.bbc.co.uk/news/health-18061174