Electrical stimulation to restore sight to the blind

Can we restore sight to blind people? Neuroscientists from the Institute of Neuroscience in the Netherlands may well have shown the way. Using electrical stimulation, they succeeded in activating the visual cortex of the monkeys, allowing them to see letters and movements. They presented their work on December 4 in the journal Science.

Create phosphenes

Stimulation of the visual cortex by electrical impulses makes it possible to circumvent the eyes to allow seeing. This stimulation produces “phosphenes”, white or gray dots that can appear when you get up too early, for example. In this case, scientists seek to organize these white dots like pixels in order to form an image. The researchers hope to be able to achieve this constitution thanks to the miniaturization of electrodes which make it possible to imagine being able to set up special glasses for blind people with a camera which sends data to a portable processor.

In their study, the researchers conducted their tests on signs. They placed 1,024 electrodes in the visual cortex of the monkeys so that they saw 1,024 pixels. They activated certain electrodes in order to create phosphenes forming a letter of the alphabet. At the same time, the images of these letters were projected onto a screen, allowing the monkey to associate the image in phosphenes with that of the letter. The results showed that the latter were able to detect which letter was represented with a high probability.

A first step

“We have discovered that it is possible to see without using your eyesrejoices Xing Chen, neuroscientist and author of the study. Blind people could recognize objects in their environment enough to have rudimentary vision. It gives hope that scientists could develop technology that would significantly help blind people.”

The authors note, however, that we are far from having found a way to completely restore sight to blind people. “Our study mainly shows that blind people could recognize objects in their environmentbelieves the researcher. However, they would see neither the colors nor the precise details of an object. It would be a new type of artificial vision that aims to assist people in need. It’s almost like going from a completely blind state to some form of bad vision. In our study, we are at just over 1000 pixels, which is very little compared to normal vision, perceiving around two million pixels.”