1. An instrument for determining the magnifying power of a microscope, or the size of a microscopic object.
  2. An instrument for detecting aniseikonia.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

Examples from the Web for eikonometer

Historical Examples of eikonometer