Bifocals

Bifocals made by Benjamin Franklin

Bifocals are eyeglasses with lenses that are split between two different strengths. Usually the lower half of each lens is made to help the wearer read, while the upper one is to help the wearer see at a distance.

Bifocals Media

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  A bifocal lens with areas of differing magnification

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  Bifocals with separate lenses. In this case, the Swedish ethnologist Jan-Öjvind Swahn.