On the plus side, these sunglasses cover my rectangular lenses perfectly and are reasonably easy to clip on. The clip is small and unobtrusive.<br /><br />On the negative side, when the sunglasses are clipped on, the ends of the clip inside the frame of the glasses are slightly prickly and uncomfortable against my forehead.  Also, the lenses of the sunglasses are fairly flimsy themselves, just thin plastic.  However, I've had similar clip-ons which lasted for a very long time, so the flimsy quality should actually not be a problem.