Different laser pointers have different wavelengths and different powers. The four-level standard laser is a high-output continuous laser, and its output power is greater than 500 milliwatts, which may cause a fire hazard. Normally used laser pointers are generally divided into four levels, below level two (04 to 1 mW). As long as the irradiation time is not long, it will generally not cause damage to the eyes and skin of the human body, but the power of the laser pointer is more than 3-5 mW. Larger, can cause human damage. At present, due to lack of supervision, some laser pointers sold around campuses have a power of 100 to 300 milliwatts, which can instantly ignite matches, firecrackers, and paper, and even cause fires. In addition, primary and middle school students lack the necessary awareness of self-protection. When playing, a long time exposure can cause damage to the retina and skin surface of the eyes, resulting in permanent damage and even blindness. According to the degree of damage that the laser system may cause to the human body, its hazard level is classified from class I lasers (no harm) to class IV lasers such as 2000 watt carbon dioxide lasers (which can cut thick steel plates). According to the relevant provisions of the EU EN-60825 standard and the "General Product Safety Regulations 2005", ordinary civil laser products can only be Class I or Class II, Class I laser products have no biological hazards, and the output power of Class II laser products is less than 1 millimeter. watt.
In addition to the different colors of the laser light emitted by different Laser pointer, there is also a different range. After reaching the sensitive parts of the human retina, it will cause damage to the eyes. In addition, after a long time seeing the dazzling light beam, it will also affect the optic nerve and central nervous system, causing people to experience dizziness and even nausea. Therefore, the laser beam must not be used to illuminate the face or eyes of others, and objects such as mirrors must not be used to reflect the laser.