Definition of “optical illusion” - English Dictionary

british dictionary

“optical illusion” in British English

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optical illusionnoun [ C ]

uk /ˌɒp.tɪ.kəl ɪˈluː.ʒən/ us /ˌɑːp.tɪ.kəl ɪˈluː.ʒən/

Examples from literature

  • For example, some scientists believe that a zebra’s stripes are not for camouflage but to make an optical illusion. When a lion sees a group of zebras, it can’t see where one zebra ends and another begins. 

(Definition of “optical illusion” from the Cambridge Advanced Learner's Dictionary & Thesaurus © Cambridge University Press)

“optical illusion” in American English

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optical illusionnoun [ C ]

us /ˈɑp·tɪ·kəl ɪˈlu·ʒən/

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.

(Definition of “optical illusion” from the Cambridge Academic Content Dictionary © Cambridge University Press)