A farsighted person who also has trouble reading may be prescribed a pair of bifocal reading glasses, for example. The upper section of the lens would correct difficulties seeing objects at distance, and the lower section would assist in reading. (Bifocal glasses date back to the days of Benjamin Franklin!)
While wearers quickly adjust to the line separating the multiple vision fields, it is a noticeable distraction within the lens itself. This line can be eliminated using a newer lens technology called progressive lenses.
Progressive lenses incorporate two, three, or more fields of vision within a single lens without noticeable lens lines. Bifocal, trifocal and progressive lenses are all considered “multi-focal” lenses—lenses that provide correction to multiple vision problems.
