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
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
![1 Pair of Photochromic Reading Glasses - Reader That Darkens When Exposed to Outdoor Sunlight - UV Protection Readers - Walmart.com 1 Pair of Photochromic Reading Glasses - Reader That Darkens When Exposed to Outdoor Sunlight - UV Protection Readers - Walmart.com](https://i5.walmartimages.com/asr/78bc1205-72b3-48a6-80d1-8940a3d9603e_1.a8f0eac364f8a17ebc2f9a8d90ffda47.jpeg?odnHeight=2000&odnWidth=2000&odnBg=FFFFFF)