Crystal glasses are not only harmful to the eyes but harmful_industry news_
There are many opinions on whether crystal glasses are good or bad. Recent studies by experts in major eyewear industries have unanimously concluded that, unlike optical glasses, crystal glasses are not only useless to the eyes but harmful. Once this statement was exposed, it attracted the attention of all walks of life. The crystal glasses with slightly better sales for a long time fell to almost zero sales. 1. Crystal glasses are more expensive, but the transparency is poor. Crystal glasses are made of natural crystalline quartz. Because of the hard texture, difficult processing, and too many impurities, the price is relatively expensive. Compared with ordinary optical glasses, the purity, transparency and clarity are significantly worse. Therefore, the visual field obtained through crystal glasses does not meet the psychological value of the wearer. Second, the crystal lens contains radioactive elements, which is harmful to human health. Although the material of crystal is high in hardness, its purity is too poor. It contains a lot of radioactive elements, radon, whether it is completely eliminated during processing. Therefore, the crystal lens contains the radioactive element radon, which is harmful to the eyes and human health. Moreover, the absorption of ultraviolet rays by crystal lenses is only 19%, and the absorption of infrared rays is only 34%, which cannot prevent ultraviolet and infrared rays from entering the eyes, which seriously endangers the health of the eyes. Third, long-term wearing of crystal glasses is easy to cause cataracts. Wearing crystal glasses and long-term exposure to the sun will cause obvious eye fatigue, which is easy to cause cataracts. In addition, compared with optical glasses, crystal glasses have a high thermal conductivity and will become stuffy after a long period of wear. Optical glasses are different. They have a cool feeling when worn, and can be well prevented and controlled. It also corrects myopia and prevents the eyes from being exposed to excessive ultraviolet rays and glare. Compared with optical glasses, crystal glasses are expensive due to their hard texture, difficult processing, difficult to grind, and low output. Optical glasses are different. These shortcomings are technically overcome, and the price is low, so the crystal glasses of the year have already been taken and worn. In addition, the ultraviolet absorption of crystal glasses is too low, and the clarity of wearing is not high, so it has been proved that it is not only useless to the eyes but harmful to the eyes.