Progressive

Progressives are lenses that combine your distance, reading and intermediate prescriptions into one lens. They look exactly like Single Vision lenses and have no visible lines on them. People who use Progressives have an advantage over people using Bifocals as they have an intermediate distance in them as well. This is used for computers or for anything that is at arms length away to be seen without having to move closer to the object they are viewing. Progressive lenses have some slight distortion on the lenses because of the way they are made. This means you have to move your head more when using Progressives so not to catch some of the distorted areas. There are several of types of Progressives and they differ by some having more distortion on the lenses than others.

A View through Progressive Lenses