One subject, 46-year-old Mikka Terho from Finland, was able to read large letters and a clock face, and differentiate between shades of gray a few days after the implant and his eyes eventually became adjusted to the light.
The chip, operated by a battery-powered cable implanted behind the ear, converts light into electrical impulses that act on the optic nerve. The device did not work on the other eight volunteers because it was implanted less deeply in the eye, according to the paper.
Link via io9 | Image: Zrenner, et al.