German scientists have invented a wireless bionic eyeball that canrestore vision to patients who have become blind due to retina damageor disease.

The new prosthetic device caps 12 years of research to help thesepatients. This work has resulted in a unique system - a fullyimplantable visual prosthesis.

The scientists from the Fraunhofer Institute for MicroelectronicCircuits and Systems in Duisburg, Germany, say that the bionic eye canbypass the damaged retina.

The system comprises an implant and an external transmitter integrated in an eyeglasses-frame.

The implant system converts the image patterns into interpretablestimulation signals, and data and energy are transferred to the implantby a telemetric link.

Nerve cells inside the eye are then stimulated according to the captured images.

The intact cells are innervated by means of 3-D stimulation electrodes that rest against the retina like small studs.

As long as there is no damage to the optic nerve, the vision signalscan be sent to the brain just like they are with healthy eyes.

"For normally sighted people that may not seem much, but for theblind, it is a major step," comments Hoc Khiem Trieu of the FraunhoferInstitute.

"After years of blindness, the patients were able to see spots oflight or geometric patterns, depending on how the nerve cells werestimulated."

Trieu has been involved from the outset of this project, which was funded by the Germany's education and research ministry.

Together with two other scientists, Ingo Krisch and DMichael Goertz,he translated the specifications given by the medical experts andmaterial scientists into an implant and chip design.

"A milestone was reached when the prosthetic system finally operated wirelessly and remotely controlled," explains Dr Krisch.

"A great deal of detailed work was necessary before the implant could be activated without any external cable connections."

"The designs became smaller and smaller, the materials moreflexible, more robust and higher in performance, so that the implantnow fits comfortably in the eye," reports Goertz.

The scientists are to receive the Joseph von Fraunhofer Prize 2008 for their work.