A prosthetic retina for implantation in an eye having a defective retina is formed from an array of nanowires having a predetermined spatial distribution, density, size and shape implanted in close proximity to the retina. An electrical conductor is formed at a first end of all nanowires in the array of nanowires and placed in contact with a bias source which biases the array. A plurality of electrodes is located on a second end of each of one nanowire or a bundle of nanowires in the array. Each nanowire produces a photocurrent at a corresponding electrode in response to detection of light impinging on the array of nanowires and the photocurrent stimulates one or more neurons adapted for visual perception. In the preferred embodiment, the predetermined spatial distribution mimics a distribution of rods and cones in a normal eye.