How can my glasses change from transparent, when I'm inside, to dark when I go outdoors? | HowStuffWorks
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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
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
![MultiLens Biocover C1 fitover sun/filter glasses, yellow lenses, allows 82% light through, dark photocromic filters. MultiLens Biocover C1 fitover sun/filter glasses, yellow lenses, allows 82% light through, dark photocromic filters.](https://www.worldwidevision.com/media/catalog/product/cache/2ce963bd942af9c6e5514438bc5ab1c1/2/7/277716.jpg)
MultiLens Biocover C1 fitover sun/filter glasses, yellow lenses, allows 82% light through, dark photocromic filters.
![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=612&odnWidth=612&odnBg=FFFFFF)
1 Pair of Photochromic Reading Glasses - Reader That Darkens When Exposed to Outdoor Sunlight - UV Protection Readers - Walmart.com
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