Photochromic lens are the kind of lens that automatically darken when they’re exposed to UV light, and automatically adjust themselves back to clear state when there’s no UV rays present. They’ve been around for some time now but were never quite practical because of low sensitivity and slow transition from one state to another. All that’s changed with the latest Transitions lens, which feature the most advanced photochromic technology ever. They now change from clear-indoors state to sunglass-outdoors state in a matter of seconds. Made from virtually unbreakable materials, I highly recommend these to anyone wearing glasses. By the way I designed these pair of lens myself, not too bad eh?
