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Optical illusion   /ˈɑptɪkəl ɪlˈuʒən/   Listen
Optical illusion

noun
1.
An optical phenomenon that results in a false or deceptive visual impression.






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"Optical illusion" Quotes from Famous Books



... the shores was a solid mountain of green on each side, the trees growing down to the water. Here the reflections were so brilliant that the dividing line between shore and water was difficult for the untrained eye to make out. The boys seemed to be gazing upon an optical illusion. From the water's edge the mountains rose sheer to a great height, their distant peaks capped with snow glistening in the morning sunlight, while glacial streams flashed over the open spaces on the ...
— The Pony Rider Boys in Alaska - The Gold Diggers of Taku Pass • Frank Gee Patchin

... every atom of vision from my eyes. For a long time I thought they must every moment disappear and resolve themselves into the movements of the branches and prove to be an optical illusion. I searched everywhere for a proof of reality, when all the while I understood quite well that the standard of reality had changed. For the longer I looked the more certain I became that these figures were real and living, though perhaps not according to the standards ...
— The Willows • Algernon Blackwood

... country, the beauty of which so surprised us, that we often asked each other what were our sensations; as if to ascertain the reality of what we saw, and persuade each other by mutual confessions of our delight, that the picture before us was not an optical illusion. The landscape alone, which varied at every turn, and gave us new beauties from any point of view, was of itself worth all the pains of an excursion to the eastward of the Jordan; and the park-like scenes that sometimes softened ...
— Palestine or the Holy Land - From the Earliest Period to the Present Time • Michael Russell

... sort of anvil. Such it appears, at least, from the Place Saint Andre des Arts. Symbolically it might be called a piteous appeal, always rejected by souls hardened and hammered by vice, of that anvil which was only an optical illusion, and that very ...
— En Route • J.-K. (Joris-Karl) Huysmans

... next attracted our attention. It presents the most perfect optical illusion imaginable; in looking up to the ceiling, which is here very high, you seem to see the very firmament itself, studded with stars; and afar off, a comet with its long, bright tail. Not far from this Star Chamber, may be seen, in a cavity in the wall on the right, and about twenty feet ...
— Rambles in the Mammoth Cave, during the Year 1844 - By a Visiter • Alexander Clark Bullitt

... yard below. A last word while we are still here: there are other reasons—one, at least, besides tragedy and crime—that make people believe this place is haunted. This particular spot is hardly one where a person would prefer to see a ghost, even if one knew it was but an optical illusion; but one evening, some years ago, when a bright moon was mounting high and swinging well around to the south, a young girl who lived near by and who had a proper skepticism for the marvels of the gossips passed this house. She was approaching it from an opposite sidewalk, ...
— Strange True Stories of Louisiana • George Washington Cable

... being very dark, these weeds could be seen standing between the fire and the guards. As the flames swayed past the weeds, the impression was very naturally produced upon the mind of a timid beholder that the weeds were moving in the opposite direction. This optical illusion caused some of the guards to believe that the Indians had set fire to the grass, and were moving in immense numbers between them and the fire with intent to surround them, stampede the cattle, and ...
— History of the Donner Party • C.F. McGlashan

... Hetty, and had come to the determination to return. Still no ark was seen. Several times the sisters fancied they saw it, looming up in the obscurity, like a low black rock; but on each occasion it was found to be either an optical illusion, or some swell of the foliage on the shore. After a search that lasted half an hour, the girls were forced to the unwelcome conviction that the ark had departed. Most young women would have felt the awkwardness of their situation, in a physical sense, under ...
— The Deerslayer • James Fenimore Cooper

... lies, as it seems, at the bottom of a huge gulf. Thus the whole visible earth appears as a vast bowl or basin. This is extremely ingenious reasoning, and not to be disregarded; but the fact remains that in the experience of the writer and of many others whom he has consulted, there is no such optical illusion as I have just discussed, and to their vision it is impossible to regard the earth as ...
— The Dominion of the Air • J. M. Bacon

... the sudden cessation of the cruel contest, an uncanny stillness fell upon the scene. Meanwhile the hidden face had flushed to the ears, and, when at length it was raised to mine, its crimson calm was as incongruous as an optical illusion. ...
— A Thief in the Night • E. W. Hornung

... or scenery; an optical device which gave a distortion to the picture unless seen from a particular point; a relief, modelled to produce an optical illusion. ...
— The Poetaster - Or, His Arraignment • Ben Jonson

... the circuit, necessarily went farther than the "Pilgrim," which gradually grew smaller in the distance. This rapidity with which objects diminish at sea has always an odd effect. It seems as if we look at them shortened through the large end of a telescope. This optical illusion evidently takes place because there are no points of comparison on these large spaces. It was thus with the "Pilgrim," which decreased to the eye and seemed already much more ...
— Dick Sand - A Captain at Fifteen • Jules Verne

... is the mirage, from the Latin miror, to wonder, which appears to be what you are doing just now. The steamer you see sailing along the shore is an optical illusion, a reflection, and not a reality. Refraction, which is the bending of the rays of light, produces this effect. If you look at a straight stick set up in the water, it will appear to be bent, and this is caused by refraction. The learned gentlemen present ...
— Asiatic Breezes - Students on The Wing • Oliver Optic

... strangely like Mr. Murray's. She leaned out and watched it till the cars swept round a curve, and lamp and figure and village vanished. How could he possibly be in Chattanooga? The conjecture was absurd; she was the victim of some optical illusion. With a long, heavily-drawn sigh, she leaned against the window-frame and looked at the dark mountain mass looming behind her; and after a time, when the storm drew nearer, she saw it only ...
— St. Elmo • Augusta J. Evans

... have been lost on them, trying to make the village. When Mr. Fentolin put up the lamp, every one thought that it would be quite safe to try and get in at night. This winter, though, there have been three wrecks which no one could understand. It must be something in the currents, or a sort of optical illusion, because in the last shipwreck one man was saved, and he swore that at the time they struck the rock, they were headed straight ...
— The Vanished Messenger • E. Phillips Oppenheim

... are longest. Roygbiv Vance taught us: red, orange, yellow, green, blue, indigo, violet. A star I see. Venus? Can't tell yet. Two. When three it's night. Were those nightclouds there all the time? Looks like a phantom ship. No. Wait. Trees are they? An optical illusion. Mirage. Land of the setting sun this. Homerule sun setting in the southeast. My ...
— Ulysses • James Joyce

... way among the blocks of ice which were carried along in the current of the Angara. A moving panorama was displayed on both sides of the river, and, by an optical illusion, it appeared as if it was the raft which was motionless before a succession of picturesque scenes. Here were high granite cliffs, there wild gorges, down which rushed a torrent; sometimes appeared a clearing with a still smoking village, then thick pine forests blazing. ...
— Michael Strogoff - or, The Courier of the Czar • Jules Verne

... Pink bowed and had all the appearance of blushing—though you will have to ask Pink how he managed to create that optical illusion. "What did you want?" he asked in his soft, girlish voice, turning to Andy bashfully. But from the corner of his eye Pink saw that a little smile of remembrance had come to soften Miss Hallman's angry features, and that the other girl was smiling also. Pink hated that attitude of pleasant ...
— The Flying U's Last Stand • B. M. Bower

... parallel Lines that do not look so—an optical Illusion almost as curious as that which makes Soldiers invisible when dressed in Combinations ...
— Punch, or the London Charivari, Vol. 153, Aug. 22, 1917 • Various

... deafening roar, and the light which it emitted became so dazzling that it nearly blinded me as I looked at it. As it came hurtling toward us it seemed to expand until it looked almost as big as the ship herself; but that was, of course, an optical illusion, for when, a second or two later, it struck us, I saw that the fiercely incandescent mass, of roughly spherical shape, was some twelve feet ...
— The Strange Adventures of Eric Blackburn • Harry Collingwood

... prepared for the objections that may be made to my story. I expect, as a matter of course, to be told that this was an optical illusion, or that I was suffering from pressure on the brain, or even that I laboured under an attack of temporary insanity. I have heard all these arguments before, and, if I may be forgiven for saying so, I have no desire ...
— Mugby Junction • Charles Dickens

... This extraordinary optical illusion was the dawn opening on the coast, then actually ten miles away, and in a very few minutes, as the cloud lifted, the land seemed to rush off to its proper distance, until at last the curtain split in two, and I found to my intense delight that ...
— The Voyage Alone in the Yawl "Rob Roy" • John MacGregor

... a traveller approaching the Himalayas from any part of the great plain of India, these mountains present the appearance of a single range, stretching continuously along the horizon from east to west. This, however, is a mere optical illusion; and, instead of one range, the Himalayas may be regarded as a congeries of mountain ridges, covering a superficies of 200,000 square miles, and running in as many different directions as there are points in ...
— The Cliff Climbers - A Sequel to "The Plant Hunters" • Captain Mayne Reid

... with this vision, which he considered merely an optical illusion, that he arose, put on his hat, and went out for a walk. Returning to the house, he determined to test the matter again—and the result was the same as before. He distinctly saw the two Lincolns—one ...
— Lincoln's Yarns and Stories • Alexander K. McClure

... From a known optical illusion derived from interference or fits of perception, as illustrated in quick moving shadows, this great speed was not realized to the eye, as the observed motion of these shadows was apparently far ...
— Scientific American Supplement, No. 441, June 14, 1884. • Various

... has in the Scotch wraith, or Irish fetch its counterpart. It has been said that people have seen friends walking to meet them, and that, when about to shake hands with the approaching person, it has vanished into air. This optical illusion was considered to be a sign of the death ...
— Welsh Folk-Lore - a Collection of the Folk-Tales and Legends of North Wales • Elias Owen

... uniformly level, like the under sides seen from the earth, but they are of a conical or pyramidal shape. These imposing masses seem to precipitate themselves upon the earth, as if to engulf it, but this optical illusion was due to the apparent immobility of the balloon, which at the moment was rising at the rate of about ...
— Wonderful Balloon Ascents - or, the Conquest of the Skies • Fulgence Marion

... come over to try and reason with this bunch of nuts. Don't you know they are so damn conceited that if you were to tell them that every time you look at a German you see two men, they would believe you; and then as if they hated to lie to themselves, they would say perhaps it was an optical illusion. Tell them that God did not create anyone but the Germans and that he left the rest of the world to the students in his office, and they will give you a smile of assent." Edestone smiled indulgently. "Tell them that when the Kaiser frowns every wheel ...
— L. P. M. - The End of the Great War • J. Stewart Barney

... turned his tube upon it, and behold! instead of twinkling points of light, he saw a round mass—a world—moving through space, and not a scintillating object with five points. The twinkling spikes, or points, were merely an optical illusion of the unaided senses. ...
— Little Journeys to the Homes of the Great - Volume 12 - Little Journeys to the Homes of Great Scientists • Elbert Hubbard

... model of those formal but reverend manners which make what is called a gentleman of the old school, so called under an impression that the style is passing away, but which, I suppose, is an optical illusion, as there are always a few more of the class remaining, and always a few young men to whom these ...
— Ralph Waldo Emerson • Oliver Wendell Holmes

... mechanically, still holding the book he had lent me clasped in my hand. Irresolutely I raised my eyes towards the "Lords of our Life and Death." It was closely veiled. I had then experienced an optical illusion. I forced myself to speak—to smile—to put back the novel sensations that ...
— A Romance of Two Worlds • Marie Corelli

... in his hands. He refused to see more. Whether ghost or optical illusion, an emanation from another world, or an image born of his remorse and proceeding from himself, it should torture his ...
— The Teeth of the Tiger • Maurice Leblanc

... scrupulously following his directions, we have, in the presence of our results, that were exactly identical with his, almost been tempted to believe ourself to be the victim of some occult power, or at least of some optical illusion, the true cause of which remained a mystery to us. Finally, after many fruitless attempts to find a key to the enigma that engaged our attention, the light finally dawned upon us, and then shone straight in ...
— Scientific American Supplement, No. 401, September 8, 1883 • Various

... believe in their existence exactly, and yet there is a strange fascination about the idea that I can't understand. Now I do not believe we saw a man walking on fog the other night, and yet I can't resist the desire to hunt the matter out and discover what sort of an optical illusion it was. I am not at all certain the man who took a shot at us was the one we saw across the ravine, either. I had an experience once when I was about nine years old, that, in a way, tainted my mind with the ghost idea, and perhaps that ...
— Pocket Island - A Story of Country Life in New England • Charles Clark Munn

... had consented. The sense of unreality and wonder which Mrs. Toomey experienced when she saw her trunk going was surpassed only by the astonishment of the neighbors, who all but broke the glass in their various windows as they pressed against it to convince themselves that the sight was not an optical illusion. ...
— The Fighting Shepherdess • Caroline Lockhart

... fact of the reverberation of the nervous structures after the removal of a stimulus, that whenever two discontinuous stimulations follow one another rapidly enough, they will appear continuous. This fact is a fruitful source of optical illusion. The appearance of a blending of the stripes of colours on a rotating disc or top, of the formation of a ring of light by swinging round a piece of burning wood, and the illusion of the toy known as the thaumatrope, or wheel of life, all depend ...
— Illusions - A Psychological Study • James Sully

... treat it with contempt. Two crucial tests were available. If it could be shown that the fantastic shapes suspended above the edge of the dark moon were seen under an identical aspect from two distant stations, that fact alone would annihilate the theory of optical illusion or "mirage"; while the certainty that they were progressively concealed by the advancing moon on one side, and uncovered on the other, would effectually detach them from dependence on our satellite, and ...
— A Popular History of Astronomy During the Nineteenth Century - Fourth Edition • Agnes M. (Agnes Mary) Clerke

... has been a perplexing one to our astronomers. Lowell observed that many of the main canals germinated a short time after the commencement of the Martian summer, and for a time it was thought that the phenomena might be an optical illusion, and the latter theory was considered seriously by some observers until the double canals were actually photographed at the Flagstaff observatory, but the cause of the doubling was never solved until ...
— The Planet Mars and its Inhabitants - A Psychic Revelation • Eros Urides and J. L. Kennon

... knot of Earthquakes, comes to the surface with Gaseous Emanations, and sliding down a Landslip, renews his journey on a ray of Light, goes through a Prism, sees a Mirage, meets with the Flying Dutchman, observes an Optical Illusion, steps over the Rainbow, enjoys a dance with the Northern Aurora, takes a little Polarized Light, boils some Water, sets a Steam-Engine in motion, witnesses the expansion of Metals, looks at the Thermometer, and refreshes himself with Ice. Soon he is at Sea, ...
— Memoirs of the Court and Cabinets of George the Third, Volume 2 (of 2) - From the Original Family Documents • The Duke of Buckingham

... mast-head, the ocean appears either flat or slightly concave, and aeronauts declare that this apparent concavity becomes more marked, the higher they ascend. It is only at those rare periods when the air is so miraculously clear as to produce the effect of no air—rendering impossible the slightest optical illusion—that our eyes can see things as they really are. So pure was the atmosphere to-day, that, at meridian, the moon, although a thin sickle, three days distant from the sun, ...
— The Lands of the Saracen - Pictures of Palestine, Asia Minor, Sicily, and Spain • Bayard Taylor

... by the aid of the same manoeuvres of the tambourine, made the goat perform many other tricks connected with the date of the day, the month of the year, etc., which the reader has already witnessed. And, by virtue of an optical illusion peculiar to judicial proceedings, these same spectators who had, probably, more than once applauded in the public square Djali's innocent magic were terrified by it beneath the roof of the Palais de Justice. The goat was undoubtedly ...
— Notre-Dame de Paris - The Hunchback of Notre Dame • Victor Hugo

... magnitude, the walls of which, once white, have been blackened by every species of exhalation. Such is, in all its simple modesty, the aspect of a temple consecrated to the worship of Bacchus and Terpsichore. At first, by a very natural optical illusion, we are struck by the confined space before us, but the eye, after a time, piercing through the thick atmosphere of a thousand vapours which are most inodorous, the extent becomes visible by details which escape in the first chaotic glimpse. It is the moment ...
— The Mirror of Literature, Amusement, and Instruction, Vol. 13, - Issue 377, June 27, 1829 • Various

... summit is both grand and beautiful. The river is of course the most attractive feature in the landscape. Far to the north and south it stretches, like a silver, sinuous thread, gradually becoming narrower until it is lost in the distance. Owing to an optical illusion the river seems to ascend in both directions, and at the points where it is lost to view, seems on a level with the eye. It is one of the best examples of this species of optical illusion to be found in this part ...
— The Bay State Monthly, Volume 3, No. 2 • Various

... east, until at about 15 degrees in the eastern horizon, it appeared to stand still for fifteen or twenty minutes. According to some descriptions it was the size of a table. To some observers it looked like an enormous wheel. The light was a brilliant white. Acceptably it was not an optical illusion—the noise of its passage through the air was heard. Having been stationary, or having seemed to stand still fifteen or twenty minutes, it disappeared, or exploded. No ...
— The Book of the Damned • Charles Fort

... yellow dot a star?" exclaims the delighted child. Poor innocent! a star had always been to him a dim, cloudy spot, a little nebula, which the magic glass has now resolved; and he can hardly believe that this brilliant point is not an optical illusion. But when his mother assures him that the stars always appear so to her, and he turns to look in her face, he says, "Why, mother! how beautiful you look! Please to give me some little spectacles, all my own!" She could not resist this entreaty,—(who could?)—and ...
— Autumn Leaves - Original Pieces in Prose and Verse • Various

... solemnly; "it's an optical illusion. Don't you know how the Indian jugglers make you see flowers growing, when there aren't any flowers there? Well, this is ...
— Patty's Social Season • Carolyn Wells

... spied an impertinent sailor grinning at him from the rigging. Instantly his legs became rigid, and he affected an interest in the horizon intended to convince the sailor that he had been the victim of an optical illusion. Of course it was quite beneath his dignity to take part in these rollicking dances, especially in such a public place as on shipboard. He realized that fully; yet he thought of Bobby and sighed. There were actually times in his life when he almost wished ...
— The Honorable Percival • Alice Hegan Rice

... canals which had previously been seen single were now distinctly double, that is, that they consisted of two parallel lines, equally distinct and either very close together or a considerable distance apart. This curious appearance was at first thought to be due to some instrumental defect or optical illusion; but as it was soon confirmed by other observers with the best instruments and in widely different localities it became in time accepted as a real ...
— Is Mars Habitable? • Alfred Russel Wallace

... may be explained either as a real miracle implying a personal appearance of Christ, or as a pious fraud, or as a natural phenomenon in the clouds and an optical illusion, or ...
— The Continental Monthly, Vol. 6, No 2, August, 1864 - Devoted to Literature and National Policy • Various

... conceal a retreat to the gap by which it had entered, and began to waddle with excessive dignity in that direction, but from the way in which it repeatedly aimed itself at the intact portions of the paling, it seemed reasonable to infer that it was under a not infrequent optical illusion. ...
— The Giant's Robe • F. Anstey

... night, at the breakfast-table. It seemed to be tacitly understood that the subject was disagreeable; and beyond an inquiry of the Doctor, "How is your patient this morning?" nothing was said. But all felt vaguely there was some mystery. Doctor Frank's theory of optical illusion satisfied no one—there was something at the bottom that they did ...
— Kate Danton, or, Captain Danton's Daughters - A Novel • May Agnes Fleming

... seen almost everything in mirage form, but what causes this Atmospheric optical illusion has never been explained to my satisfaction. Some men say it is imagination, but I do not ...
— Chief of Scouts • W.F. Drannan

... cold blood. Reading further, I was horrified to find that the young woman's name was Arletta Fogg, and that she was murdered in her own rooms, at the Seraglio Apartments, Central Park West. I could hardly believe my eyes saw the thing aright. I felt sure that it must be an optical illusion wrought by my constant thought of Arletta. I looked again and again, yet read ever the same words, and, laboring under tremendous excitement, I hurriedly perused the account of the murder. It stated that about ...
— Born Again • Alfred Lawson

... (1806-1873) was a civil engineer of prominence, and a member of the British Association and the Royal Society of Edinburgh. He wrote (1863) on "Pepper's Ghost," an ingenious optical illusion invented by him. There was a second edition of the Perpetuum Mobile ...
— A Budget of Paradoxes, Volume II (of II) • Augustus de Morgan

... optics, as we entered, we saw a beautiful nosegay in a vase, which appeared to be composed of the rarest flowers. I approached it with an intention of inhaling its fragrance, when, lo! my hand passed through it. It was an exquisite optical illusion. "Ah!" said my elegant and moralising companion, Madame S——, smiling, "of such flowers has Happiness composed her wreath: it is thus she gladdens with it the eye of Hope; but the hand of ...
— The Stranger in France • John Carr

... suggested by a political event, an incident in the police courts, a street song, or a bit of burlesque at some theatre, and forgotten in a month. Anything and everything serves to keep up a game of battledore and shuttlecock with words and ideas. The diorama, a recent invention, which carried an optical illusion a degree further than panoramas, had given rise to a mania among art students for ending every word with rama. The Maison Vauquer had caught the infection from a young artist among ...
— Father Goriot • Honore de Balzac

... room, however, a figured carpet is often preferred for practical reasons: it stands wear and tear around the table better. Well-chosen paper (See Chapter II) often improves a badly proportioned room by optical illusion. The ideal lightings for dining rooms are side lights. Dining-room drop lights or domes are very trying to the eyes of those who dine, and are unbecoming. Side lights (adding candles for grace and charm) are far pleasanter to the eyes and ...
— Prepare and Serve a Meal and Interior Decoration • Lillian B. Lansdown



Words linked to "Optical illusion" :   mirage, motion, apparent movement, movement, optical phenomenon, apparent motion



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