This is a list of visual illusions.
Name Example NotesActive shutter 3D systemActive shutter 3D system is a technique for displaying stereoscopic 3D images. It works by only presenting the image intended for the left eye while blocking the right eye's view, then presenting the right-eye image while blocking the left eye, and repeating this so rapidly that the interruptions do not interfere with the perceived fusion of the two images into a single 3D image.Afterimage illusionAn afterimage or ghost image is a visual illusion involving an image continuing to appear in one's vision after the exposure to the original image has ceased.Afterimage on empty shape (also known as color dove illusion)This type of illusion is designed to exploit graphical similarities.Ambiguous imageThese are images that can form two separate pictures. For example, the image shown forms a rabbit and a duck.AmbigramA calligraphic design that has multiple or symmetric interpretations.Ames room illusionAn Ames room is a distorted room that is used to create a visual illusion.Ames trapezoid window illusionA window is formed in the shape of a trapezium. It is often hung and spun around to provide the illusion that the window rotates through less than 180 degrees.Asahi illusion A flower-like figure with petals is arranged in a circle, which are dark on the outside and lighter in transitions toward the middle. The inner part of the background is perceived as significantly brighter than the outer background.Autokinetic effectThe autokinetic effect, or autokinesis, occurs when a stationary image appears to move.AutostereogramAn autostereogram is a single-image stereogram (SIS), designed to create the visual illusion of a three-dimensional (3D) scene from a two-dimensional image in the human brain. An ASCII stereogram is an image that is formed using characters on a keyboard. Magic Eye is an autostereogram book series.Barberpole illusionThe barber pole illusion is a visual illusion that reveals biases in the processing of visual motion in the human brain.Benham's topWhen a disk that has lines or colours on it is spun, it can form arcs of colour.Beta movementMovement that appears to occur when fixed pictures turn on and off.Bezold EffectAn apparent change of tone of a colour due to the alteration of the colour of the background.BlivetAlso known as "poiuyt" or "devil's fork", this illusion is an impossible image because in reality the shape cannot exist.Café wall illusionThis illusion is a pattern in which the mortar or grout between different coloured bricks or tiles on a wall appear to form non-parallel, straight lines, despite the lines being parallel (and straight). Its name comes from a café wall that produced the illusion.Catoptric cistulaA catoptric cistula is a box with insides made of mirrors so as to distort images of objects put into the box.Checker shadow illusionThe checker shadow illusion shows that when a shadow is cast onto a checked board, the colours of squares A and B in the photos appear to be different, when in fact they are the same.Chubb illusionThe Chubb illusion is an optical illusion or error in visual perception in which the apparent contrast of an object varies substantially to most viewers depending on its relative contrast to the field on which it is displayed.ChromostereopsisChromostereopsis is a visual illusion whereby the impression of depth is conveyed in two-dimensional color images, usually of red–blue or red–green colors.Color constancyColour constancy is an example of subjective constancy and a feature of the human color perception system which ensures that the perceived color of objects remains relatively constant under varying illumination conditions. A green apple for instance looks green to us at midday, when the main illumination is white sunlight, and also at sunset, when the main illumination is red.Color phi phenomenonThe color phi phenomenon is a perceptual illusion in which a disembodied perception of motion is produced by a succession of still images.Contingent perceptual aftereffectContingent aftereffects are illusory percepts that are apparent on a test stimulus after exposure to an induction stimulus for an extended period.Convergence micropsiaConvergence micropsia is a type of micropsia characterized by the reduction in apparent size of objects viewed when the eyes are more converged than they need to be for the distance of the object from the eyes.Cornsweet illusionAn illusion where two colours can obviously be seen to be different when placed directly beside each other; however, when the two colours are separated by a thick black line, they appear to be of the same hue.Crater illusionA type of multistable illusion where an image of a concave object, rotated so that the light source is below, may sometimes appear convex, and vice versa. This phenomenon is because light sources tend to shine from above the subject.Delboeuf illusionAn optical illusion of relative size perception. The two black circles are exactly the same size; however, the one on the left seems larger.Disappearing ModelA trompe-l'œil body painting by Joanne Gair. The dress An optical illusion resulting from the brain's attempt to discount coloured tinting from daylight and other sources. The dress was a viral phenomenon, which was either seen as blue and black or as white and gold. Its true colours were eventually confirmed to be blue and black.Ebbinghaus illusionThe Ebbinghaus illusion, or Titchener circles, is an optical illusion of relative size perception. The two orange circles are exactly the same size; however, the one on the right appears larger.Ehrenstein illusionThe Ehrenstein illusion is an optical illusion studied by the German psychologist Walter Ehrenstein in which the sides of a square placed inside a pattern of concentric circles take an apparent curved shape.Fata Morgana (mirage)Visible in a narrow band right above the horizon, Fata Morgana mirages significantly distort the object or objects on which they are based, often such that the object is completely unrecognizable. A Fata Morgana may be seen on land or at sea, in polar regions, or in deserts. It may involve almost any kind of distant object, including boats, islands, and the coastline.Fechner colorThe Fechner color effect is an illusion of color seen when looking at certain rapidly changing or moving black-and-white patterns. They are also called pattern induced flicker colors (PIFCs).Figure-ground (perception)Figure–ground organization is a type of perceptual grouping that is a vital necessity for recognizing objects through vision. In Gestalt psychology it is known as identifying a figure from the background.Filling-inFilling-in phenomena are those responsible for the completion of missing information across the physiological blind spot, and across natural and artificial scotomata.Flash lag illusionThe flash lag illusion is a visual illusion wherein a flash and a moving object that appear in the same location are perceived to be displaced from one another.Forced perspectiveApplication used in film and architecture to create the illusion of larger, more distant objects.Fraser spiral illusionThe Fraser spiral illusion, or false spiral, or the twisted cord illusion, was first described by the British psychologist Sir James Fraser in 1908. The overlapping black arc segments appear to form a spiral; however, the arcs are a series of concentric circles.Gravity hillA gravity hill is a place where the layout of the surrounding land produces an illusion, making a slight downhill slope appear to be an uphill slope. See also: List of gravity hillsGrid illusionA grid illusion is any kind of grid that deceives a person's vision.Hering illusionThe Hering illusion (1861): When two straight and parallel lines are presented in front of radial background (like the spokes of a bicycle), the lines appear as if they were bowed outwards.Hollow-Face illusionThe Hollow-Face illusion is an optical illusion in which the perception of a concave mask of a face appears as a normal convex face.Horizon dipHorizon dip, also known as a "sea dip": The horizon appears to rise from a dip in the middle distance.Hybrid imageA Hybrid image is an optical illusion developed at MIT in which an image can be interpreted in one of two different ways depending on viewing distance.Illusory contoursIllusory contours or subjective contours are a form of visual illusion where contours are perceived without a luminance or color change across the contour.Impossible objectA two-dimensional image of an impossible three-dimensional object, such as the impossible cube from M.C. Escher's 1958 print BelvedereIrradiation illusionThe irradiation illusion is an illusion of visual perception in which a light area of the visual field looks larger than an otherwise identical dark area.Isometric illusionAn isometric illusion (also called an ambiguous figure or inside/outside illusion) is a type of optical illusion, specifically one due to multistable perception.Jastrow illusionThe Jastrow illusion is an optical illusion discovered by the American psychologist Joseph Jastrow in 1889.Kanizsa triangleThe Kanizsa triangle is an optical illusion first described by the Italian psychologist Gaetano Kanizsa in 1955. It is a triangle formed of illusory contours.Kinetic Depth EffectThe Kinetic depth effect is the phenomenon whereby the three-dimensional structural form of a silhouette can be perceived when the object is moving. In the absence of other visual depth cues, this might be the only perception mechanism available to infer the object's shape. Additionally the direction of motion can reverse due to the existence of multiple 3D visual solutions.Koffka ringThe Koffka ring is a geometric optical illusion discovered by the german psychologist Kurt Koffka. Leaning tower illusionThe Leaning tower illusion is an optical illusion that presents two identical images of the Leaning Tower of Pisa side by side.Lilac chaserLilac chaser is a visual illusion, also known as the Pac-Man illusion.Lunar terminator illusionThe lunar terminator illusion is an optical illusion where the apparent source of sunlight illuminating the moon does not correspond with the actual position of the sun.Mach bandsMach bands is an optical illusion named after the physicist Ernst Mach.McCollough effectThe McCollough effect (1965) is a phenomenon of human visual perception in which colorless gratings appear colored contingent on the orientation of the gratings. It is an aftereffect requiring a period of induction to produce it.Missing square puzzleThe missing square puzzle is an optical illusion used in mathematics classes to help students reason about geometrical figures.Moon illusionThe Moon illusion is an optical illusion in which the Moon appears larger near the horizon than it does while higher up in the sky.Motion aftereffectThe motion aftereffect (MAE) is a visual illusion experienced after viewing a moving visual stimulus for a time (tens of milliseconds to minutes) with stationary eyes, and then fixating a stationary stimulus. The stationary stimulus appears to move in the opposite direction to the original (physically moving) stimulus.Motion illusionMotion illusion refers to any optical illusion in which a static image appears to be moving due to the cognitive effects of interacting color contrasts, object shapes, and position.Müller-Lyer illusionThe Müller-Lyer illusion is an optical illusion consisting of a stylized arrow.Multistable perceptionMultistable perception is a perceptual phenomenon in which an observer experiences an unpredictable sequence of spontaneous subjective changes.Necker cubeThe Necker cube is an optical illusion first published in 1832 by Swiss crystallographer Louis Albert Necker.Numerosity adaptation effectThe numerosity adaptation effect is a perceptual phenomenon in numerical cognition which demonstrates non-symbolic numerical intuition and exemplifies how numerical percepts can imp