This reader has a polarized sun clip to make a polarized sun reader. Many people want this feature but as yet they are only available from an optometrist. The polarized clip is held to the reader magnetically. This makes it possible to have the same reader for indoor and outdoor use. The frame of the reader has a spring hinge for a comfortable and flexible fit. Frame Measurements: 5 1/4" x 1 1/2" (temple to temple x height of lens)