A:Answer Reliability is going to be dependent on the manufacturer, and not necessarily the light source used by the mouse. Optical uses LED lights for tracking and laser, like its name implies, uses lasers. The laser version allows it to be utilized on any surface, where the optical might run into problems over glass and other variations. The laser also typically has more DPI (dots per inch), which allows it to be more "sensitive" to movements, something that gamers will typically require.
