Researchers at the Ecole Polytechnique Fédérale de Lausanne (EPFL) in Switzerland are investigating the possibility of partially restoring sight to the blind by using a device known as an optic nerve implant (ONI). The vision created by these ‘bionic eyes’ is known as artificial vision. The device works by bypassing the eyeball and sending electrical signals directly to the optic nerve, the pathway through which visual information reaches the brain.
For cases in which this pathway is itself damaged, a device can be implanted directly into the visual cortex. One such implant, known as ‘Orion’, was recently used with great success to restore partial vision to 6 people who had been completely blind for a number of years. However, this surgery is quite risky. ONIs allow people with damaged eyes to recover sight without the need for invasive brain surgery.The researchers at EPFL have shown that ONIs can produce specific and unique responses in the brain. This means that the artificial vision produced by the implant can theoretically inform the user about things like the location and movement of objects. When you close your eyes and put pressure on your eyelids, the flash of light that you see is known as a ‘phosphene’. In other words, phosphenes are the sensation of seeing light without any light actually entering the eye. This is roughly what artificial vision looks like, so people must undergo training in order to interpret what they are seeing.
The WHO estimate that around 1.3 billion people worldwide suffer from some sort of vision impairment. That’s about 1 in every 6 people on earth. It is easy to see how this technology could have a truly positive impact on the lives of countless real people. EPFL’s Diego Ghezzi has recently said that “from a purely technological perspective, we could do clinical trials tomorrow”.
Adam Boland – Science Editor