Quality standards of sunglasses
The eyes are the same as the skin. If you are injured by strong ultraviolet rays, prolonged exposure to the sun will increase the risk of cataracts. Therefore, when choosing sunglasses, it is important to consider its UV function. The stronger the filtering function, the better the protection effect.
Many people think that the darker the lens is, the better it can avoid the sun’s stimulation, but it is not. The darker the lens, the larger the pupil of the wearer, so if there is no ultraviolet filter function, the damage to the eye will be greater. The national quality standard for sunglasses is: it can penetrate more than 95 cages of ultraviolet rays; the light transmittance should be about 5%-30%, the bilateral lenses are quite uniform and the correction is not more than 5%, and they will not deform when viewing the object. Comfortable and beautiful. When the sun goes down, it is best to remove the sunglasses, otherwise, our eyesight will be affected in weaker places. Pay attention to the surface of the lens when choosing.
For some applications, a wider spectrum is necessary, but researchers have not yet developed lenses that change to other colors. At the same time, all color changes are the result of ultraviolet laser irradiation for a few minutes, not Through natural light. However, this new material shows that halogens are not necessary in the process of excellent change.