Why Can Color-changing Glasses Change Color
Jul 04, 2021
Color-changing glasses should actually be called photochromic glasses, which are lenses that change color with the intensity and temperature of ultraviolet rays. Different photosensitizers are added to ordinary resin lenses, such as silver halide, silver barium acid, copper halide and chromium halide. After changing color, it can be different colors, such as brown, tea gray, gray and so on.
Discoloration mechanism: When irradiated by light (especially short-wave light), the silver halide molecules in the color-changing glasses decompose into silver and halogen atoms, and many silver atoms gather together to appear light black, that is, gray. This is similar to the camera shooting process produced in photographic film. The difference is that the halogen atoms produced in the photographic film combine into halogen molecules and escape from the film, but are only a latent image composed of silver atoms; but the lens is solid, and the halogen atoms produced by light can only exist in the lens. Around the silver atom. When the lighting stops, it will immediately and reversibly return to the silver halide state, causing the lens to fade.
The following are answers to common questions about color-changing glasses:
1. The lens can change color. Will the light transmittance be affected?
The color-changing glasses can be used as sunglasses after they change color. At this time, its function is to block sunlight. At this time, the light transmittance will naturally decrease. If the original transparent transmittance is maintained, the function of the sunglasses will be lost. After the color returns, its light transmittance will return to its original state, without any effect on vision.
2. What is the reason why the color-changing lens does not change color?
There are two factors related to the color change of the color changing lens, one is the light condition, and the other is the color change factor. If it does not change color under light, then its color change factor is destroyed, so the lens cannot change color.
3. What are the special optical characteristics of color changing glasses?
Some chemicals are added to the color-changing lens, so that the originally transparent and colorless lens will become color-changing glasses for protection under strong light. It will change the intensity of the color as the intensity of the light changes. The stronger the light, the deeper the color change; the better the visual sense, the long-term use is not fatigue, and the chemical stability and mechanical strength are good. It can be used as anti-glare goggles for outdoor workers, plateau and snow workers, as well as goggles for operators and some patients with eye diseases under ultraviolet and shortwave laser conditions.
