It’s National Sunglasses Day! Have you ever wondered how self-darkening, or transition, lenses work?
It’s because of photochromic chemicals embedded in the lenses. Chemicals like silver halide and silver chromium are sensitive to UV light and that’s what cause lenses to get darker in sunlight.
Dive deeper into this topic with these resources:
How Sunglasses Work: Photochromic Lenses – This is only one part of an extensive series on how sunglasses work—a perfect summer STEM topic!
Explain That Stuff: Photochromic Lenses – The author of this article shares photos he took demonstrating the effects of photochromic lenses.
You can purchase a teacher’s guide for this topic from Teachers Pay Teachers.
Disclosure of Material Connection: Some of the links in the post above are “affiliate links.” This means if you click on the link and purchase the item, I will receive an affiliate commission. In some cases, I may have been given a free sample of a product to review. I am disclosing this in accordance with the Federal Trade Commission’s 16 CFR, Part 255: “Guides Concerning the Use of Endorsement.