bifocal lens


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Related to bifocal lens: Progressive lens

bifocal lens

[bī′fō·kəl ′lenz]
(optics)
A lens with two parts having different focal lengths.
In particular, an eyeglass lens having one part that corrects for distant vision and one part for near vision.
References in periodicals archive ?
A bifocal lens system correction eliminates the limitation of monochromatic virtual images.
For the Rao bifocal lens, the best refocusing occurs for f = -0.
That may no longer be necessary if a new bifocal lens implanted by surgeons in Columbus, Ohio, last month proves successful.