Scratch-Resistant Lens Coatings Aren’t All Equal: Hard Coats Across CR-39, Poly, Trivex and High-Index
Most semi-finished polycarbonate blanks leave the factory with a hard coat on the front only. The lab generates the back surface, so the lab also applies its scratch-resistant lens coating, after surfacing, and the order form rarely mentions it. However, that lab-applied layer decides three of the most common coating complaints: haze at three months, […]