Definitions for "PROGRESSIVE LENSES"
also referred to as "no-line bifocals"; multifocal lenses which provide visual correction for all distances. The different levels of correction are presented gradually over the lens. Typically, distance vision is corrected in the upper half of the lens, the middle area is for intermediate distances, and the lower part of the lens provides an increasing amounts of correction for close objects.
Lenses with bifocal or trifocal power with no visible line between the various focal lengths.
Lenses of multiple zones of optical power that provide both near and far focusing ability for presbyopic vision. For spectacle lenses, this is an alternative to bifocals or trifocals (elimination of tell-tale "lines" that separate lenses of differing powers). For contact lenses, these are sometimes referred to as "bifocal" contacts. But they are actually concentric rings (think "bullseye target) of varying powers that provide simultaneous near and far focusing ability. The brain ignores the fuzzy part of the image and concentrates on the high-resolution image.