eyeglasses whose lenses have two foci, allowing the wearer to see both far and nearby objects clearly. The lenses are partitioned horizontally, the upper and lower parts having different focal lengths.
Eyeglasses with divided lenses. The two parts of each lens have different strengths, allowing the wearer to focus the eye for either near or distant vision.
eyeglasses that incorporate two different powers in each lens, usually for near and distance corrections.
Corrective lenses that have two powers of correction. Typically the majority of the lens is corrected for distance vision while a small are is corrected for near vision. Bifocals and trifocals are normally prescribed for individuals with presbyopia.
Eyeglasses incorporating two different powers in each lens, usually for near and distant corrections.
Bifocals are eyeglasses that have corrective lenses containing two different optical powers. They are most commonly prescribed for people with presbyopia, and who also require a distance correction for myopia, hyperopia, and/or astigmatism.