http://www.kitlaser.com/classification-by-safety-class-4.html
Optics and Huazhong University of Science and Technology School of Electronics and Information Engineering, Professor Li Zhengjia search for medical laser nearly 40 years. He told reporters that the burning blue laser pointer is parallel to the light, shooting within the divergence angle after the small injection is "courage". Convex lens this focus on the energy soon macular area, the power will be amazing focus. More than 3 mW laser pointer, it can cause permanent damage to macular adults. Children in the eyes of the delicate fabric, and can withstand a little low, about 1 milliwatt of laser directly in the eyes, enough to burn the child with eyes. 100 yuan to buy charging green laser pen, 357,000 kilowatts of maximum power, far more than the standard toys.At present, there is no laser pen to buy more than nine brands of Chengdu, China's label, size tag no power. How is the safety of these laser pointer?