I happened to come across this article by accident, and it was very interesting. It discusses the eye diseases we learned about in class like retinitis pigmentosa and macular degeneration. We learned those disease destroy the rods and cones. However, the messenger cells stay mainly intact. So scientists are experimenting with Channelrhodopsin-2 a light sensitive protein found in green algae. The Channelrhodopsin-2 can be placed into the retina with gene therapy, bypassing the rod and come system and allowed the cells to sense light on their own. The experiment started in 2006, with mice and last month became FDA approved. Clinical trials will start at the end of the year.