Retinal prosthesis now appears feasible based on a number of recent experiments demonstrating electrical stimulation of human retina in blind subjects. We are completing development of a neural stimulating array that can be customized to function as a retinal prosthesis device. The microelectronic device has an image format of 80/spl times/40 unit cells interfaced to the curved retinal surface via an array of hundreds of thousands of microwires in a glass matrix. The system architecture and development issues are discussed as well as the topic of biocompatibility. The test device will enable acute human experiments in an operating room environment to demonstrate a massively parallel interface between retinal tissue and a microelectronic array.