Artifical eye gives sight to the blind

Before having the device fitted, each had a limited ability to perceive bright light but were unable to recognise shapes.

Within days of surgery, all three could locate objects placed on a table, including a cup, a saucer and different geometric shapes.

One patient was able to walk around a room with confidence, tell the time from a clock face, distinguish between subtle shades of grey, and read his own name.

British eye expert Professor Robert MacLaren, from Oxford University, said it had turned science fiction to fact.

Patients in the UK are due to receive the implant for the first time in a follow-up trial next year.

Two men and one woman aged 40, 44 and 38 took part in the pilot study testing the device developed by Retina Implant AG, a company based in Reutlingen, Germany.

All had the inherited condition retinitis pigmentosa, which gradually destroys the light-sensitive retina at the back of the eye eventually leading to blindness.

After first becoming affected in early childhood, each of the patients had lost the ability to read at least five years before surgery.

The implant is fitted beneath the retina and consists of a three millimetre-square array of 1,500 light sensors. Each photodiode delivers a pulsed electrical signal to adjoining nerve cells, sending a message to the brain.

A power supply unit is connected by a cable under the skin.

Tests on the patients began just seven to nine days after surgery, the authors reported.

Lead researcher Professor Eberhart Zrenner, director of the Institute for Ophthalmologic Research at the University Eye Hospital, Tuebingen, Germany, said: "The results of this pilot study provide strong evidence that the visual functions of patients blinded by a hereditary retinal dystrophy can, in principle, be restored to a degree sufficient for use in daily life."