illusion

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illusion

(Deception), noun aberration, distortion, fallacy, false impression, misbelief, misconception

illusion

(Impression), noun apparition, artifice, chimera, daydream, deception, delusion, dream, figment, masquerade, mirage, myth, optical illusion, phantasm, phantasmagoria, phantom, semblance, specter, spirit, vision, wraith
See also: artifice, deception, distortion, fallacy, figment, phantom, prestidigitation, semblance, specter, vision

ILLUSION. A species of mania in which the sensibility of the nervous system is altered, excited, weakened or perverted. The patient is deceived by the false appearance of things, and his reason is not sufficiently active and powerful to correct the error, and this last particular is what distinguishes the sane from the insane. Illusions are not unfrequent in a state of health, but reason corrects the errors and dissipates them. A square tower seen from a distance may appear round, but on approaching it, the error is corrected. A distant mountain may be taken for a cloud, but as we approach, we discover the truth. To a person in the cabin of a vessel under sail, the shore appears to move; but reflection and a closer examination soon destroy this illusion. An insane individual is mistaken on the qualities, connexions, and causes of the impressions he actually receives, and he forms wrong judgments as to his internal and external sensations; and his reason does not correct the error. 1 Beck's Med. Jur. 538; Esquirol, Maladies Mentales, prem. partie, III., tome 1, p. 202. Dict. des Sciences Medicales, Hallucination, tome 20, p. 64. See Hallucination.

References in periodicals archive ?
Despite the fact I had six of their cocktails, I wasn't having any optical illusions - unlike most of the rest of the clientele.
The result is an optical illusion that puts a bright, compact source of light in the midst of a nearby galaxy.
But in findings released by the Public Records Office the experts dismissed the British "UFOs" as either a meteorite, meteorological balloon or optical illusion.
Hero Alexander Money-Kyrle fell after Wayne Eagling into the orchestra pit because an optical illusion hid the edge of the stage.
Now, however, the two astronomers announce that spectroscopic study of one of the arcs convinces them that it is a kind of optical illusion, an image formed by a gravitational lens.
The appearance of superluminal motion is held to be an optical illusion, but the illusion imposes serious difficulties on attempts at an explanation.
Their process, called Visidep and now patented, seems to depend on a special kind of optical illusion.
If you watch as it dips behind buildings, an optical illusion is produced, which makes the moon seem even larger than it really is.
They were: My Entry Number (Neil Pesticcio from Fairwater, Cardiff); Collection (James Macleod from Splott, Cardiff); Twist and Turn (Claire Knighton from Wellington, Somerset); The Perfect Place (Iain Wootten from Taffs Well); The Other Side (Danial Sami from Canton, Cardiff); Epic (Tom Strickland from Penarth); Can't Live Without You (Lucy Owen from Canton, Cardiff); Word Search (Robert Bowen from Bridgend); Optical Illusion (Nicole Rugman from Roath, Cardiff); Equal (Alys and Emily Steed from Aberfan); Under Cover (Alanna Britten from Devizes, Wiltshire) and Eureka
There have been other suggestions on the comments of the video that it could be an optical illusion or the remains of a road.
This optical illusion is named after Ernst Mach, a physicist who described the sign in 1865.
The 50-year-old royal expert said that it was an optical illusion, Daily Star reported.