A trial at the John Radcliffe Hospital in Oxford has restored vision to a woman thanks to a 'bionic' eye implant. The woman from Cardiff, who suffers from retinitis pigmentosa, a degenerative condition that destroys light-sensitive cells in the retina, had been blind for the last six years. These cells normally carry signals from the eye to the brain along the optic nerve, which the brain processes into the images we see. When the cells stop functioning, vision is lost. 

The clinical trial involved fitting a small microchip, measuring just 3mm2, which was then connected to a micro-computer implanted behind the ear. The microchip is light-sensitive and carries out the function of the retinal cells that are not working. A hand-held control enables the patient to adjust the sensitivity of the microchip according to different conditions. 

By connecting the implant to the optic nerve – and a process of re-learning the signals it generates to the brain – the woman has been able to detect objects which she could not see before. Although the process of learning how to interpret the signals is on-going, these initial reports offer hope to many. The trial currently involves six patients but, with continued success, is likely to be extended. 

Welcoming the news, Andrew Clayton of Penningtons Manches' clinical negligence team comments: "We act for many clients whose vision has been lost or severely impaired, particularly through delays in diagnosing sight-threatening conditions or negligent surgery. For almost all of those who lose their sight, the impact is devastating, affecting not only their vision but also undermining their confidence. It leaves people unwilling to leave home and, in turn, can affect employment and relationships. 

"That this prosthetic implant has successfully restored useful vision to a patient in a clinical trial is a hugely exciting development. This is still in very early stages and more work will need to be done to evaluate the success of the device and also to assess the cost. But the result indicates a real breakthrough which, it is hoped, in time will be extended to treat other eye conditions such as macular degeneration and become available on the NHS."