In recent years, with the gradual improvement of people's living standards, all cats will go crazy when they see the laser light from a high power laser pointer. Whether it's a big cat or an old cat, this trick works pretty well. If you don't believe it, you can try it yourself. So why are cats so fascinated by laser pointers? Can they see laser light? Can their eyes feel red? In fact, cats cannot distinguish the difference between green and red because they are red-green blind. Humans have more cones than cats, and cats have more rods than humans. Therefore, even if the light is very dark, the cat's eye is also very good at capturing motion. Therefore, fast-moving prey in dim light is almost impossible to ignore for cats. So, can these two shortcomings be effectively avoided? Let's talk about security issues first.There is a tissue called the retina behind our human eyes. On the retina, there are some photosensitive pigments that can feel different colors of light. They will react differently to different colors of light, so we can see colors. However, the cat's retina does not feel the red phytochrome. In their eyes, there is no difference between red and green. Both humans and cats have two types of visual cells: cone cells and rod cells. Broadly speaking, cone cells participate in color vision and have the ability to focus and distinguish details, while rod cells are responsible for the detection of vision and motion in low light conditions.Can those laser pointers be used to tease cats?Class I laser radiation is considered non-hazardous. Class IIa laser radiation is basically harmless if the total viewing time is less than or equal to 1000 seconds. However, if it is greater than or equal to 1000 seconds, there will be chronic visual damage. Class II laser radiation is considered to cause chronic visual damage. Class IIIa laser radiation is based on the degree of radiation, which can cause acute visual damage or chronic observation damage when viewed in the beam. When viewing directly with optical instruments, it will cause serious visual damage. Class IIIb laser radiation can cause serious damage when it hits the skin and eyes directly. Class IV laser radiation can cause serious damage when it is directed or scattered on the skin and eyes.To summarize briefly, only Class I and Class II Laser pointer can be used to tease cats, and at most they can be relaxed to Class IIIa (1~5mW). Laser pointers of Class IIIb may cause damage to the eyes for a short time.