Ultraviolet (UV) light is mostly invisible to the human eye, but according to scientific testing, quite visible to many species of fish because their eyes do not have the UV filters human eyes do. That's why fish prefer low light conditions - deep water or shady areas rather than bright sunlight. Fish, as well as insects, have UV patterns to them.
Those patterns include both spots and lines. Baitfish, such as shiners and shad, also reflect UV light. Therefore, fish use UV light to search out prey. Mepps began using UV-reactive decals on our spinners in 1974 and UV-reactive paints in 1989. Our Comet TRU-V spinners, however, are UV-enhanced beyond our traditional finishes. Every Mepps Comet TRU-V features a blade and body painted with colors that are proven fish catchers. Each blade also features a dot pattern that provides maximum contrast at any depth and under all fishing conditions. We call it TRU-V. You may not be able to see it, but the fish sure can.