- Ophthalmology. having normal visual acuity.
- keenly or acutely perceptive: an opinion based on twenty-twenty hindsight.
Origin of twenty-twenty
First recorded in 1935–40
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
- med (of vision) being of normal acuity: usually written 20/20
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
- Having normal visual acuity. A person with twenty-twenty vision can see type as small as one-third of an inch at a distance of twenty feet.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.