opt-

opt(o)-

 
word element [Gr.], visible; vision; sight.
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.

opt-

Combining form denoting the eye or vision.
Collins Dictionary of Medicine © Robert M. Youngson 2004, 2005