Kiefer’s Optical Swim Goggles are a racing/all-purpose optical goggle for better vision in the pool. They feature a silicone strap and gasket with anti-fog lenses. The adjustable notched nosepiece allows for a custom fit. Use your glasses prescription by adding spherical and cylindrical measurements. Diopters are the same for both lenses. Black. Kiefer – The First Name in U.S. Swimming since 1947. Diopters are same for both lenses. Use your glasses prescription by adding spherical & cylindrical measurements. Colors: Black (clear lens) or Silver (clear lens) Available diopters: -1.5, -2, -2.5, -3, -3.5, -4, -4.5, -5, -5.5, -6, -7, -8.