Question

cbse 10th class bbc solutions​

Answer 1

Explanation:

Photochromic or "adaptive" lenses darken when exposed to UV light, such as when you walk outdoors. When you are no longer exposed to the effects of UV, (i.e. walk indoors), the lenses return to their clear state. Transitions lenses are photochromic lenses that block 100% of harmful UVA and UVB rays.Photochromic materials can be used for the design of optical switches, optical data storage devices, energy-conserving coatings, eye-protection glasses, and privacy shields. Photochromic materials and systems have several important uses depending on the rates of the optical transformations.Sunglasses or prescription eyeglasses that darken when exposed to the sun are called photochromic, or sometimes photochromatic. Developed by Corning in the late 1960s and popularized by Transitions in the 1990s, photochromic lenses rely on a specific chemical reaction to UV radiation.