A clinical trial using technology similar to that found in mobile phone cameras has enabled two previously blind patients to perceive light and shapes.

The men are taking part in a clinical trial at the Oxford University Eye Hospital and King's College Hospital in London.

A condition called retinitis pigmentosa was responsible for the loss of vision, which gradually causes photoreceptor cells at the back of the eye to deteriorate.

It marks the first time a completely blind British patient has been able to have some vision restored.

Now, a 3mm square microelectronic chip which features 1,500 light-sensitive pixels has been fitted to take over the function of the photoreceptor cells. The chip is similar to those found on board mobile phone cameras.

Signals

Electronic signals from the chip are sent to the optic nerve, which are then transmitted to the brain to be interpreted.

The chip works by providing the brain with flashes of light, as opposed to conventional vision, and works in black and white rather than colour.

At the moment vision is still pretty limited, but shapes, silhouettes and lights can be seen. It marks the first time that a previously completely blind British patient has been able to see something.

Although currently just a clinical trial, the surgeons will be fitting up to a dozen British patients with the implants, which could then be used as part of a regular treatment for those with the disease. Unfortunately, it is not anticipated that the same process will work for people with other forms of blindness.

via BBC News