Ultra light-weight moulded lens racks made from high grade optical quality plastic. Sphere lens power range, ±0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 5, 6, 7, 8, 9, 10, 12, 15 dioptres. To avoid scratching, the lenses are deeply embedded in the frame and are supplied in a soft plastic case.