The choose and buy sunglasses must understand several major parameters
Many wearing sunglasses friend when the choose and buy sunglasses, brand, appearance, price is the three things they care about. Some parameters for sunglasses, not many people know. In fact, these parameters to a certain extent, determines the function and nature of the sunglasses, so understanding of several important parameters of sunglasses, can when the choose and buy sunglasses for you to provide certain reference value. Let's learn together! The UV index - — The degree of UV UV standard refers to the meaning of: the human eye to light the perception of the range is 380 ~ 780 nm ( The visible light) , is refers to under 380 nm wavelength ultraviolet light ( Not visible) 。 UV380 meaning is under 380 nm wavelength of the light can be effectively blocked. And standard UV400 because part also blocking the visible light, so will lose some colour. In general, the vast majority of sunglasses UV index at 96% 98%. Polarization - — Polarized light, the polarization filter polarizer is the sunglasses can effectively filter out the glare, according to the principle of polarization of the light. Through effectively ruled out and filter out the scattering light beam, can make the light in eyes on track through optical axis of the visual image, make the vision clear. This lens is very suitable for driving and outdoor activities when wearing, in recent years by the vast number of consumers of all ages.