We use the Image progressive lens, one of the most technologically advanced lenses available. It minimizes side distortion with wide clear viewing areas. The progressive lens is a very good all around lens. The top part of the lens is for distance vision and the bottom of the lens is for reading vision. From top to bottom, the power is gradually increasing. As depicted the distance area is the widest, the intermediate is narrowest, with a widening reading area. To have a lens with no lines, the periphery of the lens is not optically as good as the center, so these lenses may take some time to adapt to, if you don't already wear them.