Eye implant by German scientists makes the blind see

Nov 3, 2010, 0:00 GMT

Tuebingen, Germany - A bionic implant created by German scientists enables the blind to see, picking up light and sending nerve signals to the brain, a science paper published Wednesday disclosed.

But they warned that the chip inside the eye only works for those who have lost their sight, not those who have been blind from birth.

One blind man, named by the German scientists as Miikka, was not only able to identify diverse objects such as a spoon, fork, cup and banana by looking, but also read 16 of the letters of the alphabet.

Scientists showed him the four white letters, M-I-K-A, on a black table and he promptly complained they had misspelled his name. Miikka was the only test patient to have the chip implanted under his macula, the area of the retina with the most light nerves.

A team headed by Eberhart Zrenner, a professor at Germany's University of Tuebingen did their pilot study on three patients who received the retinal chip. In the tests, patients were asked to say where objects were on the black table.

The results appeared in the journal Proceedings of the Royal Society B.

The very thin chip, measuring 3 by 3 millimetres, contains 1,500 light diodes and sends electrical signals to the nerves in the retina, which passes the signals to the brain.

This means the system only works for people who learned as babies to process visual information from the photoreceptors in their eyes.

The chip offers a partial cure for a common hereditary progressive form of blindness, Retinitis pigmentosa. In Germany alone there are 30,000 to 40,000 sufferers, an association of eye doctors said.

   Zrenner has established a company to make prosthetic aids for the blind and heads a university eye-research institute. After a wider study with 25 test patients, the chip is likely to be offered commercially, but scientists said it was too early to name a price.

http://www.doi.org/10.1098/rspb.2010.1747