There is provided an optical mechanism including a substrate, an image chip, a light source and a securing member. The method includes providing bit-loading information associated with each tone of multiple tones, where the multiple tones include a first set of tones. In another preferred embodiment, the indicator is photochromic. The drive stack may be used in conjunction with a controller to adjust the torque and speed of an ACDC electric motor. A driven wheel serves to drive a decelerating gear set. The formulations are intended for topical application to the eye, ear, or nose.