Due to sun damage, always wear sunglasses in bright daylight is very important. Sunglasses various types of lenses, lens color and special features. When choosing a pair of sunglasses, one of the first choices of consumers is to choose glass lenses or plastic lenses. Each lens can provide effective UV protection, but the benefits are not easily broken and lighter plastic and glass. However, the quality of the glass lenses are scratch resistant, and the optical performance is better than a plastic lens.
Glass sunglass lens is usually made by glass of various ultraviolet absorbing substance is added in the casting process. However, some tinted glass lenses, is capable of absorbing visible light by the plated layer of a thin coating of a colorless Cheap Oakley Sunglasses
lenses made. This coating is plated on the lens in a high temperature under vacuum. The plastic lens is the lens immersed in liquid dye to color. The depth of color is determined by the time of immersion of the lens in the dye.
Is the type of sunglasses on the ability to prevent ultraviolet? U.S. ANSI, non-profit organization is a headquartered in Washington, DC. The level of the organization to assess the level of UV protection sunglasses. The standards of the American National Standards Institute are unofficial, but up to standard manufacturers usually labeled on the sunglasses, to declare their lenses comply with the specifications of the American National Standards Institute. The label on the lens meets or exceeds Z80.3 standards of the American National Standards Institute.
American National Standards Institute standards according to the number of sunglasses absorb visible light and UV sunglasses divided into three categories - cosmetic decorative purpose, general purpose and special purpose. Beauty decorative purposes Ray Ban Outlet
absorb less than 60% of visible light. According to the standards of the American National Standards Institute, sunglasses for general use were a darker color. Special-purpose sunglasses have a deep color to prevent strong sunlight exposure. The American National Standards Institute standards set by the amount of UV-A radiation and ultraviolet B radiation limits. This limit is based on the visible light transmittance of the lens. The lens darker the need to absorb more UV-A radiation and ultraviolet B radiation.
United States AOA recommends even more stringent than the standards set by the American National Standards Institute also UV protection. American Optometry Association recommends that sunglasses provide UV-A radiation and UV-B radiation protection. In addition, the American Optometry Association to warn consumers if a manufacturer does not explicitly state their sunglasses absorb the ultraviolet, then deal with a cautious view of its good UV protection Product Description. Only with the eyes can not test the strength of ultraviolet, so consumers did not read the sunglasses before the product description, will not know the sunglasses UV protection.