Tests conducted on 21 patients with retinitis pigmentosa - a degenerative disease - that destroys light-receiving cells at the back of the eye, showed that 75 per cent of them were able to correctly identify single letters and more than 50 per cent read the four-letter words.
Lyndon da Cruz, consultant retinal surgeon at Moorfields Eye Hospital in London, said the Argus II device could "restore some meaningful vision in patients that otherwise would have been left blind".
The retinal implant converts images from an external camera into electronic signals that the brain can 'see', 'Sky News' reported.
The device is currently the only approved retinal prosthesis and consists of a camera mounted on a pair of glasses that feeds pictures along a cable to an electronic chip resting against the retina inside the eye.
The chip stimulates the optic nerve, which carries signals to the visual processing centre of the brain, giving the wearer a highly-pixelated black and white view of the world.