Photochromic

These Sunglasses feature Photochromic lenses that darken on exposure to UV radiation. Once the UV is removed (for example by walking indoors), the lenses will gradually return to their clear state. Typically, photochromic lenses darken substantially in response to UV light in less than one minute, and then continue to darken very slightly over the next fifteen minutes. All Sunglasses displayed within this category feature Photochromic Lenses.