Specialty Lenses

A lens that, because of the power, cylinder, or prism prescribed, does not lend itself to the conventional surfacing process.

A lens with different amounts of prism in different sections of the lens. Examples include prism segments, where there's a different amount of prism in the bifocal than in the distance; Franklin bifocals, a different method of achieving the same result as a prism segment; and sectional prism lenses, in which there may be several areas of the lens with different amounts of prism.

Specialized lenses designed for highly specific applications and/or working conditions. Examples include dive masks, occupational segments or spot segments.