The Science of Shade: Unlocking Photochromic Lenses | HowStuffWorks
All About Eyes Abuja - Lenses that go dark in the sun are referred to as #photochromic lenses. They have tiny molecules embedded in them that react with UV (ultraviolet) sun rays
How Fast Will Photochromic Glasses Change to Sunglasses?
The Eye Surgery & Laser Centre - Yes. Photochromic lenses turn dark and offer protection from the sun on exposure but when in most modern cars, the windscreens have UV protection properties