halometer

[ hă-lŏmĭ-tər, hā- ]

n.

An instrument used to measure the diffraction halo of a red blood cell.
An instrument for measuring ocular halos.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.