Now, the reason optical mice don't work on glass is because of the way they were built: if you have ever heard the term "laser mice" being applied to any optical mouse, the person speaking doesn't know what they're talking about. The red light emitted from the mice is just that - a light emitting diode, more commonly known as an LED. They're used in newer street lights, and are extremely bright for their size. LEDs do no "detecting" on the surface the mouse is on. They simply illuminate it, so that the "optical sensor" can do its job. Some argue that the optical sensor is a laser, but in fact, it is a miniature camera,