For patients who have lost their sight to various eye diseases, artificial retina technology allows them to experience limited vision once more.
The external parts of the artificial retina device include glasses with a mounted camera and a small computer.
The device also includes an electrode implanted onto the patient’s retina. When the camera “sees” an image, the computer is able to translate these into a pattern of neural signals. This pattern is then transmitted to the implanted electrode, and directly stimulates the optic nerve. These signals are then able to be processed by the brain and interpreted as very rudimentary images.
The first artificial retina to be implanted in a patient, known as Argus I, included only sixteen electrodes that stimulated the optic nerve. However, the patient with this implant was still able to tell the differences between light and dark, and could make out basic shapes. The newer version of the technology, Argus II, now includes sixty electrodes. However, it is still limited in that patients can only tell the differences between light and dark areas, and can only see shapes, outlines, and blurs, and not detailed images. Regardless, this is a large improvement over no sight, and patients with the implant are satisfied with simply a partial regain of their vision, and are hopeful that the technology will continue to improve. As of late, a third model of the artificial retina is in development, and will include over 200 electrodes.
Though the project began almost ten years ago, the implant has recently been approved for patients in Europe. The company has not yet submitted approval to the FDA, but hopes to do so by the end of this year.
Second Sight – How is Argus II Designed to Produce Sight?
CBS News HealthPop – First Artificial Retina Approved in Europe
US Department of Energy Office of Science – About the Artificial Retina Project