WarBird photochromic lenses are the right pick for wearing the same pair of glasses all day without the need to change lenses at the whim of the weather. Anytime you know your activity will take you through different lighting situations (such as night into day or day into night), photochromic lenses should be your choice, because they adjust automatically to the amount of sun exposure. Anti-Scratch and Anti-Fog Lens Coatings to keep things clear.