a combining form meaning “optic” or “vision,” used in the formation of compound words: optometry.
Origin of opto-
< Greek optós visible; akin to ṓps face; cf. eye
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
Medicine definitions for opto-
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.