Sunglasses detection can be divided into sunshades, light sunglasses and special Sunglasses according to their uses. According to the different transmittance, it can be divided into 0 class, 1 class, 2 class, 3 class and 4 class. With the more and more extensive use of sunglasses, the standard of sunglasses detection is also constantly updated. Recently, the European Sunglasses STANDARD EN 12312-1 has added many new test project requirements. It is believed that a new version of the domestic Sunglasses detection standard will be launched soon.

Sunglasses protect the eyes from uncomfortable glare

UV damage. All of this is due to the metal powder filter, which "selects" light as it enters. Tinted glasses selectively absorb part of the band that makes up the sun's light because they rely on very fine metal powders (iron, copper, nickel, etc.). In fact, when light hits the lens, it is reduced based on the so-called "cancellation interference" process. Jiangsu glasses detection means that when some wavelengths of light (ultraviolet A, ultraviolet B and sometimes infrared) pass through the lens, they will cancel each other when they are facing the eye inside the lens. It is not an accident that light waves overlap each other: the peaks of a wave combine with the troughs of the wave close to it, leading to mutual cancellation. The cancellation interference phenomenon depends on the refractive index of the lens (i.e. the degree of deviation when light passes through different substances from the air) and the thickness of the lens. Generally speaking, the thickness of the lens does not change much, while the refractive index of the lens varies according to the chemical composition.