Ｇlasses

Our advantage products is Acetate glasses, Metal glasses, Titantium glasses, horn glasses and Other material eyeframes .

Sunglasses, also known as sun visors, are used for shading purposes. People usually need to adjust the size of their pupils to regulate the light flux in sunlight. When the light intensity exceeds the human eye's ability to regulate, it can cause harm to the eyes.
Sunglasses can block uncomfortable strong light and protect the eyes from UV damage. All of this is attributed to metal powder filtering devices, which can "select" light when it enters. Colored glasses can selectively absorb some of the wavelengths that make up sunlight because they use very fine metal powders (such as iron, copper, nickel, etc.). In fact, when light shines on the lens, it is attenuated based on the so-called "destructive interference" process. That is to say, when certain wavelengths of light (referring to ultraviolet a, ultraviolet b, and sometimes infrared) pass through the lens, they will cancel each other out on the inside of the lens, facing the direction of the eye. The mutual overlap of light waves is not an accidental phenomenon: when the peak of a wave merges with the valley of a nearby wave, they cancel each other out. The phenomenon of destructive interference depends on the refractive index of the lens (i.e. the degree to which light deviates when passing through different substances in the air), as well as the thickness of the lens. Generally speaking, the thickness of the lens does not change much, while the refractive index of the lens varies depending on the chemical composition, and sunglasses cannot directly contact direct sunlight.