A no-line lens with a gradual blend of prescriptions ranging from the prescription for distance viewing at the top to the reading prescription at the bottom. Worn in lieu of bifocals and trifocals, which have visible lines.
a special kind of no-line multifocal that incorporates all corrections, from distance to close-up, into one lens without any separation of the various visual zones by line
a trifocal lens without visible lines separating the three visual areas
While traditional multifocal (bifocal and trifocal) lenses have a line in the middle of the lens, progressive lenses are line-free. The power gradually changes from distance correction to intermediate vision (at arm's length), to near vision (at reading distance). Go to Top
a lens that has an infinite number of focal lengths in the central corridor from the distance optical center to the near addition power. A.k.a. lineless bifocal, no-line bifocal, seamless bifocal.