Unlike common reading sunglasses with one fixed magnification, this pair lets you adjust the focus of each lens with the simple turn of a dial. With poly/nylon frames and an adjustable nose piece, their unique focusing system employs two sets of scratch-resistant polycarbonate lenses that slide over each other as one turns the outer-edge adjustment dials, which subtly changes the magnification from -6.0 diopters to +3.0 diopters. The side dials remain attached, allowing you to adjust each lens independently, and if your vision changes, you can simply give the side dials another twist, making them ideal for far, intermediate, or near distances just by turning the dials. The gray tinted lenses provide protection against damaging UVA and UVB rays. The flexible nose pads ensure a comfortable fit. Not intended as a replacement for prescription glasses, does not correct astigmatism. 1 1/2" H x 5 1/2" W. (2 1/2 oz.)