The implantation procedure, for instance, is far from routine, since the retina is as delicate as wet tissue paper and easily damaged. At the same time, Liu must encase the chip itself so that the retinal fluids do not corrode it. Another problem is that the microchip does not, at present, offer a total cure. Recent tests conducted on seventeen patients with blindness in at least one eye showed that vision improved just to the point of their being able to discern light, and, at best, to make out shapes and identify colors. One problem is that the bandwidth limitations only permit the chip to transmit about one hundred pixels.
Researchers hope to increase that to five hundred pixels to make the image sharper.
The tests involved implanting electrodes directly into the retina for a few minutes in the operating room. The chip itself was outside the eye. Further tests will be conducted on blind dogs using the full-vision system of retinal implants and goggles for the first time. In addition, researchers will be testing to see how the retinal prosthesis works over the long term. If these tests succeed, the next step is testing the retinal prosthesis on humans and applying for FDA approval.