1. An apparatus for controlling the stimulation of retinal tissue comprising: a retinal stimulator; an input device for providing input for neural stimulation; at least one electrode driven by the neural stimulator and suitable to stimulate neural tissue; a device capable of determining a charge per phase by calculating a discrete integral of the wave form of the input for the at least one electrode; a calculating device for comparing the charge per phase to a predetermined maximum and determining a reduced stimulation for the at least one electrode by the amount necessary not to exceed said predetermined maximum for the at least one electrode; and a current pulse generator for stimulating said retinal tissue according to said reduced stimulation level.