The challenge of rechecking vision
Wicab is working with the University of Pittsburgh Medical Center's UPMC Eye Center for further testing on BrainPort. Optometrist Amy Nau will test it, along with other artificial devices such as retinal and cortical implant chips, in order to develop criteria for monitoring the progress of artificial sight.
"We can't just throw up an eye chart. We have to take a step back and describe the rudimentary precepts that these people are getting," Nau says. "The images are in black and white, pixilated. How do you recheck vision?"
Nau is particularly interested in the BrainPort because it is non-invasive, unlike implants.
The key to the device may be its utilization of the tongue, which seems to be an ideal organ for sensing electrical current. Saliva there functions as a good conductor, Seiple said. Also it might help that the tongue's nerve fibers are densely packaged and that these fibers are closer to the tongue's surface relative to other touch organs. (The surfaces of fingers, for example, are covered with a layer of dead cells called stratum corneum.)
"Many people who have acquired blindness are desperate to get their vision back," Nau says. Although sensory substitution techniques cannot fully restore sight, they do provide the information necessary for spatial orientation. Along with the blind, the BrainPort could help people with visual defects such as glaucoma, which leads to the loss of peripheral vision, and macular degeneration, which degrades sight at the center of the visual field.