/ Thesaurus / O Synonyms of optical illusion Find synonyms for: Noun1. optical illusion, optical phenomenonusage: an optical phenomenon that results in a false or deceptive visual impressionWordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: immense Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language