Do sunglasses protect against UV rays? _Sunglasses knowledge_
For the sunglasses that everyone likes very much, some people think that all the sunglasses have the function of anti-ultraviolet, but it is not true. Some unqualified sunglasses not only have poor anti-ultraviolet ability, but also cannot protect the eyes. Damage, whether sunglasses can protect against ultraviolet rays is determined by the material of the lens. 1. Generally, genuine sunglasses have a good ability to prevent ultraviolet rays. In the case of good light transmittance, the lenses need to filter out more than 90% of ultraviolet rays. This kind of sunglasses has the effect of anti-ultraviolet rays and can filter out 100% of the ultraviolet rays. % UV is better. Of course, genuine sunglasses have good UV protection. When choosing sunglasses, look at the UV index of the sunglasses. We can look at the label of the sunglasses. The label of the lens has instructions for UV protection. Second, you can check whether the sunglasses have the effect of anti-ultraviolet through experiments. You can check whether the sunglasses have the effect of anti-ultraviolet through experiments. Prepare the banknote detector pen and 100-yuan bills that are usually used, and turn on the currency detector and irradiate the 100-yuan bill. On the pattern of the banknote, a clear 100 pattern can be seen. When the sunglasses are placed on the top of the 100-yuan bill, and then illuminated with a banknote detector, because the sunglasses have the effect of anti-ultraviolet rays, the 100-yuan pattern is invisible. , if it is still very clear under the irradiation of ultraviolet light, it proves that the sunglasses do not have the ability to protect against ultraviolet rays. 3. Sunglasses that cannot protect against ultraviolet rays are very harmful to the eyes. Sunglasses that cannot protect against ultraviolet rays are very harmful to the eyes. This is because after wearing sunglasses, part of the visible light is blocked, and the pupils will naturally enlarge, which is more harmful. Light can enter the eye and damage the eye. If you don't wear sunglasses, your pupils will naturally shrink when your eyes encounter strong light. It can reduce the entry of harmful rays, so it is better not to wear sunglasses that are suitable for ultraviolet rays. When buying sunglasses, everyone should pay attention. It is better to choose those brand sunglasses, or some well-known sunglasses. Don't buy them casually at roadside stalls. If you go to some professional optical shops to buy them, it is more secure. A good pair of sunglasses can not only effectively filter out ultraviolet rays, but also can distinguish the color of things very well, and the lens surface is smooth and flat.