Are polarized glasses UV resistant?
Polarized lenses provide UV protection, but less protection.
The primary function of polarized sunglasses is to protect against UV rays and filter polarized light. Good polarized sunglasses lenses can block more than 90 percent of the penetration of UV rays. Polarized sunglasses with the ‘UV400’ Best UV Blocking logo have the best UV protection.
Polarizer is a lens manufactured according to the principle of polarization of light, which can exclude and filter scattered light in the beam, prevent ultraviolet rays and filter polarized light. A good polarizer can achieve the color of the surrounding environment without distortion, the edge of the object is clear, it can effectively identify the signal lights of different colors, and reduce the effect of ultraviolet rays irradiating into the pupil.
Polarizers are like blinds, which only block part of the light, but still let the light (including ultraviolet rays) basically parallel to the polarization angle. The shielding rate is less than 50 percent. From the perspective of protection, it is equivalent to giving the window A layer of soft yarn was added, but it was only partially occluded. The biggest advantage of polarizers is to block the interference of glare and make the visual effect clearer, and the protection against ultraviolet rays is not as good as reflective sunglasses and color-changing mirrors.
How to judge polarized light Does the sunglass have UV protection?
1. Look at the label
UV protection sunglasses have labels or lenses that say ‘UV protection’ , ‘UV400’ and other obvious signs. ‘UV index’ is the effect of filtering out ultraviolet rays, which is a very important criterion for purchasing sunglasses. Light with a wavelength of 286nm-400nm is called ultraviolet light. Generally speaking, a 100 percent UV index is impossible. The UV index of most sunglasses is between 96 percent and 98 percent.
Sunglasses
with anti-ultraviolet function generally have the following express ways:
(1) Mark ‘UV400’: This means that the cut-off wavelength of the lens to ultraviolet is 400nm, that is, its The maximum value ??max(??) of the spectral transmittance at the wavelength (??) below 400nm is not more than 2 percent.
(2) Mark ‘UV’ and ‘UV protection’: this means that the lens is resistant to ultraviolet The cut-off wavelength is 380 nm, that is, the maximum value ??max(??) of the spectral transmittance at a wavelength (??) below 380 nm is not more than 2 percent.
(3) Mark ‘100 percent UV absorption’: This means that the lens has 100 percent UV absorption function, that is, its average transmittance in the UV range is not greater than 0.5 percent.
Sunglasses that meet the above requirements are the true sunglasses with UV protection.
2. Use banknotes + banknote detectors to verify
In the case of no instrument, ordinary people can also detect whether the sunglasses have the function of anti-ultraviolet . Take a banknote, put the sunglasses lens on the anti-counterfeiting watermark, and take a photo on the lens with a money detector or a money detector. If you can still see the watermark, it means that the sunglasses are not UV-resistant. If you can’t see it, it means The sunglasses are UV protected.
Declare: The above methods are derived from the program system index or shared by netizens. They are for your reference only and do not represent the research views of this website. sex and authority.