A visual prosthesis apparatus and a method for limiting power consumption in a visual prosthesis apparatus. The visual prosthesis apparatus comprises a camera for capturing a video image, a video processing unit associated with the camera, the video processing unit configured to convert the video image to stimulation patterns, and a retinal stimulation system configured to stop stimulating neural tissue in a subject's eye based on the stimulation patterns when an error is detected in a forward telemetry received from the video processing unit.