Cataract is the biggest killer of human vision, and 95% of people over the age of 70 have cataract of varying degrees
Ultraviolet rays are a major cause of cataracts, such as high altitude and strong ultraviolet radiation**, the incidence of cataract is 60% higher than that of other regions.
Studies have shown that ultraviolet light can cause protein denaturation and reduced hydration in the lens of the eyeball, resulting in cloudiness, leading to cataracts.
So what if we spend a lot of time outdoors in strong sunlight, such as hiking, skiing, farming?Preferably with a wide-brimmed hat and sunglasses.
For the eyeball, UVB rays up to 320 nm are mainly absorbed by the cornea, while UVA rays above 320 nm are mainly absorbed by the lensIn sunlight, the UVA content is much greater than that of UVB, so to protect the lens from cataracts, the main thing is to shield UVA.
At present, the domestic ultraviolet national standard for sunglasses GB39552 requires 280nm and 380nm ultraviolet transmittance requirements of <1%.
The standard is required to have a shielding rate of 99% at 280 380nm ultraviolet rays, which is to take into account that But we often say that it is a hooligan to talk about toxicity regardless of dose, as can be seen from the proportion of light absorption by the eyeball in the figure above, the proportion of 400nm ultraviolet rays entering the lens is as high as 82% 96%, even if the long-wave ultraviolet rays are less destructive, but they can't resist the large amount. As a result, special products were born on the market, namely UV400 sunglasses, which block all UV rays up to 400nm. UV400 is a sign of top ultraviolet protection performance, so all the young ladies and sisters who love beauty, in addition to choosing sunglasses, there is a UV400 logo is a plus, especially for those who like long-term outdoor sports, wall cracks are recommended. So the question (guang gao) is, what does this have to do with the plastic additives we are concerned about? Yes!Benzotriazole ultraviolet absorbers are commonly used in the lens industry, and their absorption peaks are as follows (red frame), and the absorption at 390nm is already very weak. If you want to shield ultraviolet rays within 400nm, you need to use long-wave ultraviolet rays for better absorption effect, Taiwan Qi Ti chiguard@ GA403 is born for this purpose, the product is a new type of ultraviolet masking agent derived from vanillin, and its absorption peak is as follows: It can be seen that the absorption rate of chiguard@ GA403 at 380 400nm is still very high, and 0. is added to 1mm PET15% is enough to block all UV rays up to 405nm. Secondly chiguard@ the background color of GA403 is relatively light, which is very important, because many blue light absorbers can also absorb UV and high-energy blue light around 400nm, but the excessive absorption of visible light by blue light absorbers will cause the initial color of the product to be yellowish, which will cause color distortion for visual purposes. chiguard@ GA403 has little visual impact due to its small dosage and relatively light color. In addition, chiguard@ GA403 is FDA approved for use in food and beverage packaging, which can protect vitamins or certain food colors (caramel color in the picture below) from UV damage, so as to maintain the function and appearance consistency of beverages and foods. Of course, having said chiguard@ GA403 has so many advantages, a very special masking range, light color, high efficiency, and even FDA. You will be able to understand that he may have a drawback: "expensive". However, in practical application, due to the high efficiency, the actual cost is not as high as the unit price seems, and the addition amount can achieve the same shielding effect at 1 5 of UV326. Finally, the frightening ECHA (European Chemicals Agency) has sentenced or will be sentenced to death for the most commonly used benzotriazole series of UV320 UV326 UV327 UV328 UV329, which will be phased out in the EU, so being more environmentally friendly is a bonus benefit of chiguard@ GA403. If you need to protect the contents of the product while keeping it colorless and transparent, such as the lens of the eyeball, UV-sensitive vitamins (e.g., vitamin A C K E B ETC, commonly used in functional drinks and foods), UV-sensitive pigments, or to meet certain UV protection standards (e.g., JIS L1925 requires testing UV absorption at 290 400nm), then chiguard@ GA403 is a good solution. Interested friends are welcome to communicate and test. 
