Retinal Prosthesis Phosphene Perception — 2D Field Map

An epiretinal implant restores rudimentary vision by driving current through an electrode array resting on the retina, exciting nearby ganglion cells and producing a perceived spot of light — a phosphene. This 2D version renders the same clinically-grounded model as a flattened current-density field computed on a grid (a fundus-style retinal map) next to a perceived-visual-field chart, with a live brightness-vs-frequency parameter curve. Current amplitude sets how much retinal tissue is activated via a threshold current-spread relation; the retina's eccentricity-dependent magnification factor then converts that physical activation into a phosphene of a specific angular size; pulse frequency separately drives a saturating brightness response. Live readouts track the activated-tissue radius, the phosphene's visual angle, and its perceived brightness as you adjust each control.