Geordi La Forge in Star Trek: The Next Generation has been blind since birth, but uses a device called a VISOR to "see" the environment around him. The VISOR is able to scan an electromagnetic spectrum much wider than what human beings are normally able to perceive, and then transmits the visual data through an implant to the optic nerves.
Second Sight Medical Products (Sylmar, CA), in fact, has its Argus II Retinal Prosthesis System. The Argus II is able to identify images through a miniature video camera mounted on eyeglasses, turns the images into electrical pulses, and then sends the pulses wirelessly to electrodes that have been implanted on the retinal surface. New five-year data shows the Argus II was able to restore some vision for its users. Granted, it is nowhere near what the fictional VISOR was able to do, but it's a start.
[Argus II promotion image courtesy of Second Sight Medical Products. Image of Geordi La Forge courtesy of Wikipedia]