A “bionic eye”, which was surgically implanted into the retina of six blind patients, was successfully able to restore partial vision among them, thus holding out promise that the device could supplement human vision in the future.
The success of the eye has prompted researchers to start a new trial involving more patients to the tune of about 50 to 75 patients. The bionic eye works on the mechanism of triggering electrical signals into nerves by converting images from a small camera on a pair of glass eyes.
“It's amazing that even with 16 pixels how much our subjects have been able to do,” said Professor Mark Humayun of the University of Southern California, who is the pioneer behind the device. “We were completely wrong...We thought from simulations that 16 would only give you distinction between light and dark and maybe some grey scale.”
He added that one of the patients Terry Byland was even able to distinguish between objects like cup and a knife. The 58-year-old Byland went blind in 1993 from a condition called retinitis pigmentosa. "At the beginning, it was like seeing assembled dots - now it's much more than that," he recalls. "When I am walking along the street, I can avoid low-hanging branches; I can see the edges of the branches, so I can avoid them."
Prof Humayun spent 16 years researching for the device and it is still in its nascent stages. However it will not be of any use in conditions where blindness is caused by extensive damage to the optic nerve or vision-processing centres within the brain. But it can still be used in a variety of conditions that lead to loss of vision. Age-related macular degeneration is one such condition.
Humayun believes that the device is capable of restoring vision only in those people who once had it and not in those who are blind from birth. "I don't think it will be as effective as somebody who had vision into their 20s, 30s and 40s, but it is definitely a population we would like to try," he added.
