Why photochromic glasses turn dark when exposed to sunlight?
The lenses of photochromic lenses are made of glass that is mixed with minute crystals of light-sensitive silver iodide or bromide. The crystals are so tiny that they have a length of only 50 angstroms, and to make its length clearer, a single angstrom is equivalent to 0.0000000001 meters. As these crystals … Read more