1. an instrument to test oculomotor balance.
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.
An instrument for measuring heterophoria consisting usually of Maddox rods and rotary prisms mounted on a phoropter or trial frame.
Millodot: Dictionary of Optometry and Visual Science, 7th edition. © 2009 Butterworth-Heinemann