[ trī-fō′kəl, trī′fō′- ]
A lens having one section that corrects for distant vision, a second section that corrects for intermediate vision, and a third that corrects for near vision.
Retro Words You’ll Probably Never Use AgainMost of these retronyms -- obsolete words and phrases -- are outdated technologies.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.