Outdoor activities in the eye by adjusting the size of the pupil to protect their eyesight. When adjusting the light intensity of more than ability to protect the eyes, the eyes will hurt. Cheap Ray Bans Wayfarer Sunglasses Outlet Sale Sunglasses can reduce eye strain, prevent cataracts caused by ultraviolet light keratitis. Therefore, in order to truly protect your eyes with sunglasses selection is very important, can not stop the UV eye sunglasses will bring greater harm.
Must be able to block UV sunglasses
In the ultraviolet emitted by the sun, only 280 to 400 nm wavelength ultraviolet light can reach the ground. In order to prevent UV damage to the eyes, sunglasses lenses to be able to block most of the medium-wave and long-wave ultraviolet light. Therefore, the quality of sunglasses lens material is very important. Plastic sunglasses with polycarbonate lenses are made of plastic. Polycarbonate plastic is bisphenol A and phosgene or acetone condensation polymer material is generated. Bisphenol A molecule which benzene ring moiety portion of the ultraviolet absorbing group, and each structural unit in the polycarbonate molecule contains two benzene ring structure. Therefore, polycarbonate plastic ring system containing a large amount of UV energy through the lens barrier. But the real high-quality lenses that should be used for Fake Oakleys Frogskins Sunglasses Cheap for Sale glass production. In glass production process to add a small amount of sodium and iron oxide, silicon oxide additives due to the destruction of the structure of the continuous absorption of ultraviolet light, so the glass can block UV rays.
Mirror of the eyes will be more comfortable to wear
While the above two lens material is UV damage can prevent eye, but to get eyes feel more comfortable, better color sunglasses effect.
Mirror of ultraviolet radiation can be used by the photochemical reaction reversible dye production. Photochemical reaction is reversible when the phenomenon of a substance subjected to light irradiation and light disappears; it undergoes a reversible color change. Plastic photochromic lens is used in polycarbonate plastic photochemical added colorless dye production. In the sunlight, the dye absorbs ultraviolet reversible rearrangement reactions, the absorption of visible light generated isomers, the lens showing deep black color. When you no longer exposed to sunlight, chemical reactions occur reverse this dye, so that the weight of new heterogeneous return colored and colorless isomer, Therefore, the lens can return to a colorless state.
Color change color Cheap Mac Cosmetics Makeup wholesale Outlet glass lenses silver bromide used in the production process of such a glass lens to be added microcrystalline silver and copper bromide. Mention should first talk about silver bromide photographic film. When subjected to ultraviolet radiation, the film of silver bromide emulsion will happen in the photochemical decomposition reaction of black silver particles can absorb bromine and Free State of visible light. The free state of bromine is generated once it is absorbed on the film emulsion, bromine, and silver cannot regenerate silver bromide. Therefore, the photosensitive photographic film process is not reversible. However, in a photochromic glass lens, the silver atoms and bromine atoms are fixed in the glass impossible position, they can recombine to generate silver bromide. When no UV irradiation, silver bromide can no longer decompose the glass lens to return to the colorless state, And long-term repeated use, the advantages of using a photosensitive silver bromide agent as its function is not changed over time, and photochemistry of organic dyes as sensitizers will gradually increase time resolution.
Buy a polarizer to do specialized testing
Now people can buy dark polarized sunglasses on the market. Since the lens only allows light through the surface of certain vibration, which enables light entering the eye greatly diminished. Therefore, polarized Tiffany and Co Key Necklace Jewelry Outlet sunglasses protect eyesight. However, when purchasing such sunglasses, sellers must check out a special picture. If you see the graphic disappears through the lens, is the real polarized sunglasses.