Ask if it's better to buy PC or PA for eyeglasses

It seems the 5th floor's expertise in lenses is not up to snuff! [s:17] PC is a thermoplastic material like PA, and PR is a thermosetting material! PA refers to PAAM, also known as acrylic, generally used for frame shaping piece, high material acrylic can be used for lenses, generally used for presbyopia! A company in Danyang has exclusively developed an acrylic lens with excellent optical properties, and the PA mentioned by LZ may be this kind of lens! PR refers to resin lenses, the best optical performance is CR-39, refractive index 1.499, produced in the United States Columbia Resin Company (PPG), the name means Columbia Resin No. 39! This lens is a prescription lens in foreign countries and is designated as a wearable lens for those under 18 years of age! Currently, CR-39 has become synonymous with resin lenses in China! The two best quality monomer raw materials for the popular 1.61 resin lenses are PPG's NK-55 and Japan's Tokuyama's TS-46, whose optical properties are very stable! The 1.56, which has the largest domestic sales volume, is actually not available abroad! It was developed by Tokuyama of Japan according to the special situation in China, using the material code TS-42. At that time, the Japanese might only want to earn more money from the Chinese, but they did not expect that the Chinese would popularize the 1.56 refractive index lenses abroad! Currently 1.56 monomer material used the most is made in Korea! View original post>>