any of various instruments for measuring the refractive error of an eye.
Origin of optometer
First recorded in 1730–40; opto-
Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
Examples from the Web for optometer
Historical Examples of optometer
In using the optometer, find the place where vision of the dots is the easiest and most distinct.
Test with optometer, and in reporting use the number on the stem preceded by F for far-sightedness, and N for near-sightedness.
Now, the Javal-Bull optometer permits of a quick determination of the value of the amplitude of accommodation in dioptries.
British Dictionary definitions for optometer
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
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.