Tags: bifocals, eyeglasses
|Did you know?... Bifocals are common eyeglasses as people age. A
bifocal is an eyeglass that has two strengths of lenses. The upper part of
the bifocal helps people with seeing things in the distance. The lower
lens on a bifocal helps people see things up close. Benjamin Franklin
invented the bifocal lenses in 1784.