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Quest for prosthetic retinas progresses toward human trials, with a VR assist – TechCrunch

An artificial retina would be an enormous boon to the many people with visual impairments, and the possibility is creeping closer to reality year by year. One of the latest advancements takes a different and auspicious approach, using tiny dots that convert light to electricity. Virtual reality has helped show that it could be a viable path forward. These photovoltaic retinal prostheses come from the École Polytechnique fédérale de Lausanne, where Diego Ghezzi has been working on the idea for several years.

Early retinal prosthetics were created decades ago, and the basic idea is as follows: A camera outside the body (on a pair of glasses, for instance) sends a signal over a wire to a tiny microelectrode array, which consists of many small electrodes that pierce the nonfunctioning retinal surface and stimulate the working cells directly.

The problems with this are mainly that powering and sending data to the array requires a wire running from outside the eye is — generally speaking, a “don’t” when it comes to prosthetics and the body in general. The array itself is also limited in the number of electrodes it can have by the size of each, meaning for many years, the effective resolution in the best case scenario was on the order of a few dozen or hundred “pixels.” (The concept doesn’t translate directly because of the way the visual system works.)

Ghezzi’s approach obviates both these problems using photovoltaic materials, which turn light into an electric current. It’s not so different from what happens in a digital camera, except instead of recording the charge as in the image, it sends the current into the retina like the powered electrodes did. There’s no need for a wire to relay power or data to the implant because both are provided by the light shining on it.

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