Laser lights have strong directionality and brightness, and improper use can cause personal injury. Their safety levels are divided into Class 1 to Class 4 according to international standards, and different levels correspond to different use scenarios and safety requirements. Class 1 is a safe level with extremely low power (≤0.4mW), which will not cause harm even if it directly irradiates the eyes, and is mostly used for children’s toys and popular science displays. Class 2 has a power of ≤1mW, only red light. Short-term irradiation of the eyes will produce an irritating reaction, and it is only necessary to avoid long-term direct viewing. Class 3R has a power of ≤5mW, and the beam brightness is relatively strong. Direct viewing will cause temporary visual damage. It is necessary to avoid direct irradiation of the eyes and it is forbidden to be used for children to play. Class 4 has a power of >5mW, which is a high-power laser. It can not only burn the eyes, but also ignite flammable items. It is only used in professional scenarios, which need to be operated by professionals and equipped with protective equipment. In daily use, do not buy high-power laser lights as toys, and avoid direct beam irradiation on eyes and skin when using.（lightspace）
