The original ordinary glass is the main component of silicate, and as optical glass lenses, as well as potassium composition. This optical glass is hard, not easy to wear, sharpness, and in the manufacture of color lens glasses, in addition to the general raw materials, but also the right amount of silver halide and copper oxide micro-crystal, made of lenses, which Silver halide is broken down into silver and halogen when exposed to bright light:
2AgX = 2Ag + X2
Because the silver particles are dark, so the lens color becomes darker. When the light dim (weak), silver and halogen in the role of copper oxide catalyst, and re-synthesis of silver halide:
2Ag + X2 = 2AgX
So the color of the lens is lighter again. So the secret of discolouration is the decomposition and recombination of silver halide under different conditions. According to the experiment, it is proved that the lens of the color changing lens is 50% of the original light after being exposed to the sunlight for 5 minutes, and the light can be restored by 23% after the lens leaves the sunlight for 5 minutes. After about 1 hour, The original character.
As the added silver halide and copper oxide have been integrated with the optical glass, so discolored glasses can be repeatedly discolored, long-term use, both to protect the eyes from strong light stimulation, but also play a role in correcting vision.