The International Symposium on Artificial Retinal Prosthesis (September, 2009) demonstrated various methods of implanting chips to provide vision. A German study indicated that some patients were able to read letters eight centimeters high. In one of the systems, a chip, implanted under the cells of the retina, converts light to electrical signals, which are sent to the retinal nerve cells. Two other German researchers place a camera into eyeglasses, which then conveys data to the chip, which converts it to electrcal impulses that are then sent to the retinal nerves.