Bionic-boosted eyes go hi-def

AAAS A new version of an electronic implant which restores visual capabilities in blind people holds untold promise, those gathered at a meeting in San Francisco heard today, as the technology behind the device is taken to the next level.

Back in 2005, the news that a man who had been blind for 50 years had regained some sight with the help of an implant in his eye grabbed headlines worldwide.

As we noted back then, the retinal implant proved more effective than the scientists had predicted. With just 16 pixels to work with, patients' brains have adapted to the point where they can distinguish a cup, a plate and a knife, as well as detect movement.

The new version of the implant cranks the resolution up almost fourfold to a whopping 60 pixels.

On Thursday, the team behind those original six groundbreaking subjects, five of whom still use the device, told reporters at the American Association for the Advancement of Science's annual get together they were ready to move on to surgery to insert the more advanced iteration. University of Southern California professor Mark Humayan explained: "What we are trying to do is take real time images and convert them into electrical pulses that will jump-start the otherwise blind eye."

As first time round, test subjects will wear glasses with a discrete camera built into the nosepiece. The AM signal from the camera is sent to the implant via a processor which coverts the image so that the electrodes in place of the damaged retina can communicate it to the optic nerve.

Humayan would not be drawn on what patients might be able to see, given that last time the expectation was for no more than the ability to distinguish light and dark, and at most rudimentary greyscale. The team, backed by commercial partner Second Sight, recently got FDA approval to go ahead with operations to insert the device into patients with retinal damage. The approach has no effect on cases where the blindness is caused by damage to the optic nerve by disease or trauma.

Humayan said he hopes version two of the technology will be clinically available in two years, and its cost should be comparable to a cochlear implant for deafness, which is around $30,000. ®