Definition: A progressive lens is a corrective lens used in eyeglasses to correct presbyopia.
A progressive lens gradually and seamlessly changes in power to provide clear distance, as well as intermediate and near vision with no visible segments or demarcation lines.
Progressive lenses are often referred to as invisible, no-line bifocals. Many people prefer the look of progressive lenses over bifocals, as they look like single vision lenses.
Also Known As: No-line bifocal, PAL (progressive addition lens ), varifocal lens
