Better 'bionic eye' offers new hope

Profoundly blind people could get their best shot yet of restored vision with a more advanced "bionic eye", researchers have announced.

Trials of the new retinal prosthesis will begin shortly, following the success of a prototype that has enabled six blind people to see again.

Within a few weeks all could detect light, identify objects and even perceive motion again. For one patient, this was the first time he had seen anything in half a century, after his sight was destroyed by retinitis pigmentosa, a virus that attacks retinal cells.

Currently recipients of the device experience a relatively narrow view, but more electrodes should provide a greater field of vision, Humayun says. By stimulating more ganglion cells, he hopes that visual acuity will increase dramatically. His team's next goal is to design a device with 1000 electrodes.