Macular degeneration leads to blindness due to loss of the “image capturing” photoreceptors, while neurons in the “image-processing” inner retinal layers are relatively well preserved. Photovoltaic subretinal prosthesis converts light into pulsed electric current, stimulating the nearby inner retinal neurons. Clinical trial with such implants having 100um pixels, as well as preclinical measurements with 75 and 55um pixels, confirm that spatial resolution of prosthetic vision can reach the pixel pitch. For a broad acceptance of this technology, visual acuity should exceed 20/100, which requires pixels smaller than 25um. I will present 3-dimensional electro-neural interface scalable down to cellular-scale pixel size.
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