In a rare surgical feat, British doctors have fitted a blind man with a bionic eye that has given the 73-year-old "eyesight".

A team at the Moorfield's Eye Hospital in London, led by Lyndon da Cruz, has carried out the "experimental" surgery seven months back on Ron who lost his eyesight 30 years ago, the BBC News website reported on last Wednesday.

The bionic eye, known as Argus II and developed by US company Second Sight, uses a camera and video processor mounted on sunglasses to send captured images wirelessly to a tiny receiver on the outside of eye, according to the doctors.

In turn, the receiver passes on the data via a tiny cable to an array of electrodes which sit on the retina--the layer of specialized cells that respond to light at the back of the eye.

When these electrodes are stimulated they send messages along the optic nerve to the brain, which is able to perceive patterns of light and dark spots corresponding to which electrodes have been stimulated, they said.  The hope is that the patients will learn to interpret the visual patterns produced into meaningful images.

Cruz was quoted as saying: "We are very encouraged by the trial's progress so far. The implants have been stable and functioning for six months, with consistent visual perceptions generated by the device".

Cruz was quoted as saying: "We are very encouraged by the trial's progress so far. The implants have been stable and functioning for six months, with consistent visual perceptions generated by the device".

It is designed to help the people, like Ron, who have been made blind through Retinitis pigmentosa, a group of inherited eye diseases that cause degeneration of the retina.

The disease progresses over a number of years, normally after people have been diagnosed when they are children.

Ron, who has not revealed his name, said: "For 30 years I've seen absolutely nothing at all, it's all been black but now light is coming through.  Suddenly to be able to see light again is truly wonderful"