A bionic eye implant that could help restore the sight of millions of blind people could be available to patients within two years. US researchers have been given the go-ahead to implant the prototype device in 50 to 75 patients. The Argus II system uses a spectacle-mounted camera to feed visual information to electrodes in the eye. Patients who tested less-advanced versions of the retinal implant were able to see light, shapes and movement. "What we are trying to do is take real-time images from a camera and convert them into tiny electrical pulses that would jump-start the otherwise...