[ op-tom-i-ter ]
/ ɒpˈtɒm ɪ tər /


any of various instruments for measuring the refractive error of an eye.

Origin of optometer

First recorded in 1730–40; opto- + -meter
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for optometer

  • Now, the Javal-Bull optometer permits of a quick determination of the value of the amplitude of accommodation in dioptries.

  • In using the optometer, find the place where vision of the dots is the easiest and most distinct.

    Degeneracy|Eugene S. Talbot
  • Test with optometer, and in reporting use the number on the stem preceded by F for far-sightedness, and N for near-sightedness.

    Degeneracy|Eugene S. Talbot

British Dictionary definitions for optometer

/ (ɒpˈtɒmɪtə) /


any of various instruments for measuring the refractive power of the eye
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

Medicine definitions for optometer

[ ŏp-tŏmĭ-tər ]


An instrument for determining the refraction of the eye.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.