The Philadelphia is a blue blocking computer reader. The blue rays from computers and other electronics are blocked to protect the viewer. Some people even have come to the conclusion that blue rays can affect sleep. The lenses of these blue blockers are clear and look exactly like regular readers. The frame on this style has a spring hinge for a comfortable and flexible fit. Frame Measurements: 5 1/8" x 1 5/8" (temple to temple x height of lens)