Abstract: A low power indicator for electro-active spectacle lenses is presented in which the low power indicator is a part of a controller for the electro-active spectacle lenses or is operably connected to the controller. The low power indicator may generate a signal when the power of the power source for the electro-active spectacle lenses is low. The signal may be used by the controller, or other circuitry to activate an indication to a user of the lenses that the power is low. Such an indication may be periodically activating and deactivating one of an optical power of the electro-active lenses, a vibration source, a visible light source, or an audible sound source.