Electronic eyes battling blindness

Two totally blind patients have received eye implants in an innovative and revolutionary trial at the Oxford Eye Hospital and King’s College Hospital, London. The electronic implants have resulted in both men becoming partial sighted with the ability to perceive lights and some shapes.

This incredible advance involved the insertion of a wafer-thin microelectronic chip with light-sensitive pixels into the eye behind the retina with a cable running to a control unit placed under the skin behind the ear. The chip works by sensing the light entering the eye, stimulating the pixels to send an electronic signal to the brain via the optic nerve.

The two British men both lost their vision due to retinitis pigmentosa, a condition where the photoreceptor cells at the back of the eye lose their ability to function. One of the patients, Chris James, said that when the implant was switched on it was a “magic moment”. The chip works by picking up light and vision will therefore be in black and white but the other patient, Robin Millar, found that for the first time in 25 years he has dreamt in colour. Although this development may not seem much to sighted individuals, Professor Robert MacLaren one of the leaders of the trial, has said that the ability for a totally blind person to be able to know where doors and windows are in a room and be able to orientate themselves is incredibly useful.

It is thought that up to a dozen British patients with retinitis pigmentosa will be fitted with the implants as part of the initial trial but this raises the potential for future eye implants to be fitted in patients with macular degeneration, the most common form of progressive blindness.

Loss of transparency of the lens of the eye. Full medical glossary
The basic unit of all living organisms. Full medical glossary
The basic unit of genetic material carried on chromosomes. Full medical glossary
A progressive disorder affecting the area of the retina responsible for seeing fine detail. Full medical glossary
In physics it is the tendency of a force to twist or rotate another object Full medical glossary
Bundle of fibres that carries information in the form of electrical impulses. Full medical glossary
Continuously increasing in extent or severity. Full medical glossary
The light sensitive membrane that lines the back, inner surface of the eye and enables sight. Full medical glossary