An apparatus and method are provided for a night vision system including a transparent overlay display that transmit direct-view light representing an intensified image and emits display light representing a display image. To reduce the communication bandwidth with an external controller, a frame buffer is provided to locally update pixel values of the display image, at a first frame rate. Because many pixel values remain unchanged from frame to frame, an external controller may change the pixel values stored in the frame buffer as needed, reducing the amount of information that is needed from the external controller to control the display image. Additionally, to reduce the communication bandwidth the display information may be communicated from the external controller using a high-level language. Further, some of the display information may be determined using a local processor, rather than relying on the external controller for the display information.