Color changing sunglasses
Many car drivers often wear a pair of black glasses when driving. When driving in the sun or snow, this pair of black glasses can protect the eyes from the long-term irritation of strong light. However, when the car suddenly drove from the light to the dark, wearing black glasses became a burden instead. It is too inconvenient to wear it for a while and pick it up for a while. Is there any good way to relieve the driver’s distress? Have. Wear color-changing glasses. In the sun, it is a pair of black sunglasses, with dark glass lenses blocking the dazzling light. In the softly lit room, it becomes transparent and colorless like ordinary glasses.
The mystery of the color-changing glasses is in the glass. This special glass is called “photochromic” glass. In the manufacturing process, it is pre-mixed with light-sensitive substances, such as silver chloride, silver bromide (collectively referred to as silver halide), etc., and a small amount of copper oxide catalyst. The color of the spectacle lenses changed from no color to light gray and dark brown, and then from black spectacles to tone glasses. It is the magic of silver halide.” In the glass of the color-changing spectacles, there are changes that are very similar to the exposure imaging of photosensitive film. Process. The silver halide decomposes when exposed to light and turns into many black silver particles, which are evenly distributed in the glass, so the glass lens appears dim and blocks the passage of light. This is black glasses. However, it is different from the situation on the photosensitive film. , The silver atom and halogen atom generated after the decomposition of silver halide are still close together. When returning to a darker place, under the promotion of copper oxide catalyst, silver and halogen recombine to produce silver halide, glass lens It became transparent again.
