A video camera transmits images to a processor, which displays the images on an LCD screen on the inside of patient's goggles. The LCD display transmits infrared light pulses that project the image to photovoltaic cells implanted underneath the retina. The photovoltaic cells then convert light signals into electrical impulses that in turn stimulate retinal neurons above them. (Credit: Stanford University.)
Researchers at Stanford University recently announced that they have developed a new artificial retina implant that uses photovoltaic power and could help the blind see. The problem with previous implants was that there was no way send power to the chip in order to process light and data inside the eye. Now, miniature photovoltaic cells are being used to provide power to the chip as well as to transmit data through the eye to the brain. The new device has great promise to help people afflicted by the loss of photoreceptor cells by using the power of the sun.
The device is placed behind the retina and is essentially an array of mini solar devices. In addition, the system utilizes is an external video camera that captures images, a pocket PC to process the video feed and a bright near-infrared LCD display built into video goggles, which transmit infrared light pulses to the photovoltaic device in the eye. The light pulses then produce electricity in the device, which transmits data through the eye so the brain can process it into a hazy picture.
The implant is built to a width of 3-mm wide and 0.03-mm thick, and includes three layers of flexible photovoltaic cells mounted with silicon posts. This new system is capable of producing vision of 20/200, which is beyond what is considered legally blind, but the researchers reasonable expect to achieve 20/100, which would produce a picture clear enough that a person could recognize faces and read large print.