Black Light Vision create the black light effect through the iPhone camera. A black light, also referred to as a UV light or ultraviolet light, is a lamp that emits ultraviolet radiation (UV) in the long-wave (near ultraviolet, UVA) range, and little visible light. Other types of ultraviolet lamp emit large amounts of visible light along with the ultraviolet; but a "black light" usually refers to a lamp that has a dark blue optical filtering material in the glass envelope of the bulb (or the lamp housing) which blocks most of the visible light, so the lamp emits mostly ultraviolet. Black Light Vision does not produce UV light.