The FDA has approved a bionic eye developed by Second Sight Medical Products Inc. for use to treat one form of blindness, effectively giving the patients some sight. The Food and Drug Administration action allows the Sylmar medical device firm to immediately sell the device in the United States. It is used to treat patients who are blind due to a disease called retinitis pigmentosa, which kills the cells in the retina that process light. “This is a game changer in sight-affecting diseases, that represents a huge step forward for the field and for these patients who were without any available treatment options until now,” said Second Sight Chief Executive Robert Greenberg in a statement. The Argus II device, technically known as a retinal prosthesis, can be implanted into the eye in about two hours. Patients wear glasses with tiny video cameras mounted on them, which capture images in the form of light. The data is wirelessly sent to the implant, which triggers electrodes that stimulate the retina. The result is that patients can see images in black and white. Second Sight plans to make the device available later this year. The approval comes 20 years after firm, co-founded by entrepreneur Alfred Mann, started research and development of the device, which is already available in Europe. Mann is the company’s chairman.