Bionic Eyes

Artificial retinas constructed at SVEC consist of 100,000 tiny ceramic detectors, each 1/20 the size of a human hair. The assemblage is so small that surgeons can't safely handle it. So, the arrays are attached to a polymer film one millimetre by one millimetre in size. A couple of weeks after insertion into an eyeball, the polymer film will simply dissolve leaving only the array behind.

The first human trials of such detectors will begin in 2002. Dr. Charles Garcia of the University of Texas Medical School in Houston will be the surgeon in charge.

Image courtesy A. Ignatiev. These first-generation ceramic thin film microdetectors, each about 30 microns in size, are attached to a polymer carrier, which helps surgeons handle them. The background image shows human cones 5-10 microns in size in a hexagonal array.

"An incision is made in the white portion of the eye and the retina is elevated by injecting fluid underneath," explains Garcia, comparing the space to a blister forming on the skin after a burn. "Within that little blister, we place the artificial retina."

Scientists aren't yet certain how the brain will interpret unfamiliar voltages from the artificial rods and cones. They believe the brain will eventually adapt, although a slow learning process might be necessary - something akin to the way an infant learns shapes and colours for the first time.

"It's a long way from the lab to the clinic," notes Garcia. "Will they work? For how long? And at what level of resolution? We won't know until we implant the receptors in patients. The technology is in its infancy."

Ignatiev has received over 200 requests from patients who learned of the studies from earlier press reports. "I'm extremely excited about this," he says. He cautions that much more research is needed, but "it's very promising."