Of course not. Purple flashlights are widely used, in fact, not only to detect fluorescent agents; It is also the main working light in crude oil detection, exploration, banknote inspection and jewelry appraisal. It can immediately illuminate a part of the surrounding environment with fluorescent agent; For example, when clothes are irradiated by ultraviolet rays, the purple flashlight is normally a blue beam of weak visible light, and it will have a fluorescent reaction when it meets the color of fluorescent agent. It can not only detect fluorescent agents, but also look at stones and jade.