Lenses that darken automatically when exposed to various levels of light are called photochromic or light-adaptive lenses. This technology was discovered in the 1960s, but it didn’t really catch on until the 1990s. The convenience of photochromic lenses is huge: they’re basically like getting two complete pairs of glasses—regular glasses and sunglasses—in one! How the…
Read more
Photochromic Lenses
