Solution:
Method 1: Look at the label of sunglasses
Sunglasses with UV protection function generally have the following express means:< /p>
Marked “UV400”: this means that the cut-off wavelength of the lens for ultraviolet is 400 nm, i.e. the maximum value τmax (λ) of the spectral transmission at wavelengths (λ) less than 400 nm is not more than 2%;
Marked “UV” and “UV Protection”: this means that the UV cut-off wavelength of the lens is 380 nm, i.e. the maximum value of its transmission spectral τmax (λ) at a wavelength (λ) less than 380 nm
Not more than 2%;
Marked “100% UV absorption”: this means that the lens has 100% absorption function for ultraviolet rays, that is, its average transmission in the ultraviolet range does not exceed 0.5%.
Method 2, use ban ticketsthan + a money detector pen to check
In the absence of instruments, ordinary people can also detect whether sunglasses have UV protection function.
Take a banknote, place the lens of the sunglasses on the anti-counterfeiting watermark, and use a banknote detector pen or banknote detector to take a photo of the lens. If the watermark is still visible, it means that. the sunglasses are not UV resistant, if you can't see it, it means the sunglasses are UV resistant.
Detailed information:
Professional testing methods:
1. Lens UV Transmission Detection Principle
The transmission measurement of sunglasses lenses cannot be treated as a simple average of the spectral transmission at each wavelength, but must be obtained by intweighted egration of the spectral transmission according to the different weights of the different wavelengths.
The human eyeball is a simple optical system. When evaluating the quality of eyewear products, we must first consider the sensitivity of the human eye to light radiation of different wavelengths.
2. Lens UV transmission detection instrument and method
Connect the spectral transmission meter to the serial port of the computer, start the operating program, and carry out environmental calibration at 23℃±5℃ (Before calibration, need to confirm that there is no lens or filter in the measuring part), set the test wavelength range to 280~480nm and observe the UV state of the lens while enlarging the transmission curve.
After that, place the lenses to be tested on the test rubber caps to test the light transmission.re (note: wipe the test lenses and rubber caps before testing).
Reference materials: Baidu Encyclopedia - Sunglasses
Polarized sunglasses are better. Ordinary sunglasses only use the light reduction function, because ordinary lenses cannot filter light. . , so they can only reduce the intensity of glare, ultraviolet light, etc., but cannot completely block these harmful rays, so their function is only to reduce eye damage, but the biggest benefit of general sunglasses is their popularity. Polarized lenses, due to their polarizing properties, can completely block light caused by various factors such as scattering, refraction and reflection.The resulting glare. At the same time, it can also completely block ultra raysaviolets harmful to human eyes, so when people are active under strong light for a long time, the eyes will not get tired easily, thus achieving a real protective function and making things easier. seen more clearly and in three dimensions.