Progresive lenses is a lens with one prescription on the top for distance and a different prescription down below for reading. They have the advantage in that between the top and the bottom is an intermediate zone that's very good for computer. The disadvantage of progressive lenses is that the field of vision is not as wide, and so if I'm looking at you, the vision's clear straight ahead but off to the side, it's not quite as clear so I have to turn my head. And that's just a little bit inconvenient, you have to take some getting used to.