Sight restoration comes into focus: versions of visual prostheses.

The first visual prosthetic is on the commercial stage now, and a variety of new retinal and cortical implants are in the wings. When it won the European stamp of approval last year, the Argus II became the first commercially available visual prosthesis. Now Second Sight Medical Products Inc. of Sylmar, California, the company behind the Argus II, hopes to receive approval to sell the device in the United States by late 2012. As the excitement over the Argus II continues at a fever pitch, other research groups are developing their own versions of visual prostheses, working to create the potential for restoring sight.