Nidek created a research lab for artificial vision in 2001.

The target of the research is blind patients who once had vision. The artifical vision sends electrical pulses to the nervous system, and the stimuli are transferred to the brain so that light will be recognized.
Nikkei.Net has a story about the current status of the Nidek Artificial Vision Research.
Nidek has a working prototype that supports 16pixels. It is not tested yet on humans. Until 2005 the resolution is supposed to go up to 100pixels, which would allow a human to count fingers from 30cm distance.
Full story on Nikkei.NET (subscription). See also Nidek Artificial Vision Research Page.