While the end result is similar to the BrainPort technology that lets you the blind "see" through their tongue, the team at Bionic Vision Australia actually delivers electrical impulses directly to neurons in the retina:
Bionic Vision Australia uses an external camera - with resolution of up to 5 megapixels - mounted on a pair of glasses. An electrode array is implanted in the eye and that connects to the central part of the retina where the greatest number of retinal neurons are present. An external unit has vision-processing software to help generate the electrical impulses. The communication between the electrode implant and the external unit is wireless.
Currently, the images that are seen are limited to around 100 pixels, but Bionic Vision Australia is also working on a platinum-based (instead of the polycrystalline diamond of the first) model that could achieve 10 times that resolution. That degree of clarity would allow for recognising faces and reading large print.