Electric field shaping for high resolution in photovoltaic retinal prosthesis

Sight can be restored in patients who lost photoreceptors due to atrophic AMD by substituting them with a photovoltaic array. Subretinal pixels convert pulsed NIR light projected from augmented-reality glasses into electric current, stimulating the nearby inner retinal neurons. Patients with such implants can simultaneously use their residual peripheral sight and central prosthetic vision, and its acuity closely matches the 100um pixel size of the implant. We present two approaches to selective neural stimulation with pixel sizes down to 20um – optically configurable current steering and 3-dimensional honeycomb-shaped electrodes, both providing prosthetic acuity matching the natural resolution in rats.