The Argus II Retinal Prosthesis System (“Argus II”) is the world’s first approved device intended to restore some functional vision for people suffering from blindness. Argus II is approved for use in the United States and the European Economic Area.
The Argus II system is made up of three parts: a pair of glasses, a converter box, and an electrode array. The glasses are a vehicle for the camera – and that camera is similar to your smart phone. The image from the camera is then transmitted down into a converter box that can be carried in a purse or pocket. This box sends signals to the electrode array implanted onto the patient’s retina. Essentially, what the Argus II does is skip over the cells that retinitis pigmentosa has killed to get visual signals to the brain.
Robert Greenberg, the president and CEO of Second Sight, the company that developed Argus II, explains that the eye is like a multi-layer cake. On one layer are the light-sensitive cells, called “rods” and “cones”, that sighted people rely on to take in light and turn that into visual information. But for those with retinitis pigmentosa, those cells are dead. “We’re bypassing those dead cells and going to the next layer of the cake,” Greenberg explains.
This means that Argus II has to convert the information from the camera into signals that the electrodes implanted in the eye can use, and that the brain can interpret. Figuring out how to achieve that was the focus of Greenberg’s PhD thesis. But there was a bigger hurdle to come, he says: working out a way to implant electrodes onto the paper-thin retina inside the eye.
>So what do people using Argus II actually see? Greenberg says it’s best imagined as looking like a pixelated image, or staring at a digital scoreboard held just in front of your eyes. There are regions of light and dark that collectively the brain recognises as an image.
>Fulton, however, says it’s difficult to describe exactly what she sees. “People say you’ll see shapes,” she says. “Well yeah but it’s the electrical impulses, and it’s about learning how to interpret them. It’s not that it’s hard, it’s just a learning curve. It’s something that I’m learning.”[SOURCE](http://www.bbc.com/future/story/20140923-im-blind-but-i-have-bionic-eyes)