Optics. a large lens with a surface of concentric grooves of prismatic profile, used in automobile headlights, searchlights, spotlights, etc.
Retro Words You’ll Probably Never Use AgainMost of these retronyms -- obsolete words and phrases -- are outdated technologies.
A giant eyeball is a Web craze, so what do you call the stuff inside the ball?Sometimes the Internet community gets a little twitterpated about random stuff. In this case, a 30-foot sculpture of an eyeball in Chicago has transmogrified artist Tony Tasset into an online celebrity. Web searches on “giant eyeball” went bananas. Let’s use this eye mania as an excuse to take a look at some of the wonderful names for the parts of our beloved lamps. Like the zonule of Zinn. What …
Origin of Fresnel lens
First recorded in 1840–50; see origin at fresnel
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
a lens consisting of a number of smaller lenses arranged to give a flat surface of short focal length
Word Origin for Fresnel lens
C20: named after Augustin Jean Fresnel (1788–1827), French physicist
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
[ frə-nĕl′ ]
A thin optical lens consisting of concentric rings of segmental lenses and having a short focal length. Placing a light source at the focal point of the lens gives rise to a strong beam of nearly parallel rays. Fresnel lenses are used primarily in spotlights, lighthouses, and the headlights of motor vehicles.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.