Cambridge Dictionaries online Cambridge Dictionaries online

The most popular online dictionary and thesaurus for learners of English

English definition of “optical illusion”

See all translations

optical illusion

noun [C]  /ˈɑp·tɪ·kəl ɪˈlu·ʒən/ us  
something that you think you see, but that is not really there: Some sort of optical illusion makes these things seem to travel faster than they really do.
Translations of “optical illusion”
in Chinese (Traditional) 視錯覺, 光幻覺…
in Russian оптический обман…
in Turkish göz yanılması, optik yanılsama…
in Chinese (Simplified) 视错觉, 光幻觉…
in Polish złudzenie optyczne…
(Definition of optical illusion from the Cambridge Academic Content Dictionary © Cambridge University Press)
What is the pronunciation of optical illusion?
Add Cambridge dictionaries to your browser to your website

Definitions of “optical illusion” in other dictionaries

Word of the Day

luck out

to be very lucky

Word of the Day

Think long and hard; the language of decisions

by Liz Walter,
January 28, 2015
One of the best ways (perhaps the best way) to improve your English is to learn how words go together in phrases, idioms, or other patterns such as verb/noun or adjective/noun pairs (often called ‘collocations’). This blog looks at some useful phrases and collocations connected with the subject of decisions, something we

Read More 

micro pig noun

January 26, 2015
an extremely small pig, bred to be a pet Micro pigs have become popular pets recently, with famous owners including Victoria Beckham, Paris Hilton and Olympic diver, Tom Daley.

Read More