The current thinking on visual prosthetics is that the implants that allow people with damaged eyes to see should be behind the retina. This has been shown to work for some people but not all. Now, researchers at Harvard Medical School have reported research supporting the idea of deep brain implants, for the simple reason that some eye patients don’t have enough retinal neurons left to benefit from sub-retinal implants.
The Harvard research advocates implanting small devices in the visual cortex, bypassing the weak retinas altogether. The devices are then stimulated, along with the lateral geniculate nucleus, which is normally charged with transferring sight signals from the retina. The result is by and large the same as if the retina is recording visual data: The brain sees things.
The Harvard research will continue with a larger number of implants, on animals first. Trials on animals have been largely successful, leading researchers to believe that such implants might work on humans.