Abstract: An automatically operated, moving illuminated display for a helmet, disposed upon the rear thereof. The display is mounted on a module which adheres to the exterior of the helmet, as by hook and loop fastener. The illuminated display is provided by a series or matrix of light emitting diodes mounted to the module. Controlling electronic circuitry, a battery cell, and one of two actuating switches are also disposed upon the module. One actuating switch, located within the helmet and connected to the module by a cable, is a contact responsive switch which is tripped when the user dons the helmet. The other switch, mounted to the module, is a light sensor, which is exposed to ambient light and is responsive to fading daylight. At a predetermined ambient light level, and when the helmet is donned, power is supplied to the controller. The controller sequentially illuminates the LED display in stages, thus creating the visual impression of motion.