The meaning of the UV standard means that the human eye perceives light in the range of 380 to 780 nm (ie visible light), and ultraviolet light refers to light having a wavelength below 380 nm (invisible light). The meaning of UV380 is that it can effectively block light with a wavelength below 380 nm. The UV400 standard loses some of its color because it also blocks some of the visible light.
The color saturation makes the outline of the object blurred, making the eyes tired and uncomfortable. Polarizers are made according to the principle of polarization of light, that is, when the plane of vibration of the light is parallel to the axis of polarization, the polarizing filter can transmit polarized light (like the principle of blinds). Thus, the light is organized into the same direction light into the human eye, making the surrounding scenery look clear without glare. Another outstanding advantage is that the sheet is extremely light, extremely thin (thickness 0.8mm, 1.1mm) and impact resistant, so this lens is very suitable for driving and outdoor activities, and has been favored in recent years.
Those who drive are more likely to wear polarized sunglasses, because in addition to blocking UV rays, polarizers can minimize and filter out reflected glare. For example, the strong light of the opposite car when driving, or the strong glare formed by the sun-irradiated window film attached to the rear window by the sun, allows the wearer to clearly see the things in front.