Introducing the new Birdz Women's Line. Stylish frames, lenses that are shatter resistant polycarbonate, rated UV400. Comes with a soft micro-fiber bag to store them in. Tortoise Shell frames with brown gradient lenses. brown gradient lenses are shaded from top to bottom. They are tinted from the top down, so that the top of the lens is darkest; they're good for driving so that the dashboard and instrument panels are seen clearly.