This is a high quality progressive lens used in no-line bifocals. Progressive lenses are a type of no-line bifocal that gets stronger the further down the glasses you look. Many people like progressive lenses because they can “dial in” the amount of bifocal they need by tilting their head. Other people find progressives uncomfortable, however, because of the distortion in their lower vision. The Varilux brand of progressive lenses are of a higher quality and seem to be better tolerated with less distortion.