These are all the first prize winners from the last dozen years or so in the annual Best Illusion of the Year Contest.

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2021 - The Phantom Queen
Matt Pritchard, UK



The main illusion in this video shows a chess board and its reflection in a mirror. However, there’s a phantom White Queen piece that only appears as a reflection, leaving a mysterious empty square in the foreground. The illusion is achieved by creating a camouflaged invisibility cloak that shields the Queen from one viewing angle. The shape and pattern of this shield also disguise its presence when viewed from a second angle that comes from the mirror’s reflection. The video also shows other applications of this anamorphic camouflage to create a remarkable magical appearance and an invisible cube.

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2020 - 3D Schröder Staircase
Kokichi Sugihara, Meiji University



A traditional Schröder staircase is a 2D picture having two interpretation, a staircase seen from above and that seen from below, and the second interpretation can be perceived easily if we turn the picture upside-down. The present 3D object also has two interpretations, both of which are staircases seen from above, and the interpretations switch from one to the other when we rotate the object by 180 degrees around the vertical axis.

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2019 - Dual Axis Illusion
Frank Force, USA



This spinning shape appears to defy logic by rotating around both the horizontal and vertical axis at the same time! To make things even more confusing, the direction of rotation is also ambiguous. Some visual cues in the video will help viewers change their perception.

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2018 - Triply Ambiguous Object
Kokichi Sugihara, Japan



The object generates three different interpretations when it is seen from three special viewpoints. Most of existing ambiguous pictures/objects, such as Necker cube and Schroeder staircase, generate only two interpretations. The present object consists of a 2D picture of a rectangular structure and a pole with a flag. The picture is placed on a horizontal surface and it is seen in slanted directions so that one group of parallel lines appears to be vertical. Then we perceive three different structures because they are compressed in different directions. The pole with a flag represents the direction of the gravity, which strengthens the illusion.

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2017 - Shape from motion only
Hedva Spitzer, Dana Tearosh, Niv Weisman; School of Electrical Engineering. The Iby and Aladar Fleischman Faculty of Engineering. Tel Aviv University. Israel



The phenomenon “Shape from Motion Only” presented in its purest form in the video i.e., the information is only in the temporal domain, without any clues in the spatial domain. Both the object and the background are created by flashing the pixels on and off, while the only difference is expressed in the temporal properties. We examined various properties of the phenomenon such as: statistics and object size. Furthermore, we examined how several known optical illusions like “Rubin’s Vase” might occur using this temporal phenomenon. This research has the potential to open a hatch for better understanding the visual system mechanisms.

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2016 - Motion Integration Unleashed: New Tricks for an Old Dog
Mathew T. Harrison and Gideon P. Caplovitz, University of Nevada Reno, USA



Previous illusions have demonstrated that drifting Gabors that translate across the visual field can appear to move in the wrong direction (i.e. in a direction that is different than the actual translation). Here we show that configurations of drifting Gabors that are stationary can give rise to dramatic global motion percepts: a rotating square, oscillating chopsticks and rolling waves. Although the Gabors themselves are not changing position, the drifting motion within them causes the illusion that the entire configuration is moving!

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2015 - Splitting Colors
Mark Vergeer, KU Leuven (Belgium)



The Splitting Color illusion is all about how we perceive colors. We start off with two identical, flickering colored stripes that remain unchanged throughout the demonstration. However, different surroundings will make these stripes appear completely different. When the stripe is flanked by a yellow/blue pattern, drifting to the left, it changes appearance, and looks red and cyan, drifting to the right, while the same stripe, flanked by a red/cyan pattern drifting to the right, suddenly looks yellow and blue, drifting to the left. This illusion shows that one and the same object can look completely different depending on its surroundings.

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2014 - The Dynamic Ebbinghaus
Christopher D. Blair, Gideon P. Caplovitz, and Ryan E.B. Mruczek, University of Nevada Reno, USA, USA



The Dynamic Ebbinghaus takes a classic, static size illusion and transforms it into a dynamic, moving display. A central circle, which stays the same size, appears to change size when it is surrounded by a set of circles that grow and shrink over time. Interestingly, this effect is relatively weak when looking directly at a stationary central circle. But if you look away from the central circle or move your eyes, or if the entire stimulus move across the screen, then the illusory effect is surprisingly strong – at least twice as large as the classic, static Ebbinghaus illusion.

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2013 - Rotation Generated by Translation
Jun Ono, Akiyasu Tomoeda and Kokichi Sugihara, Meiji University and CREST, Japan



This illusion concerns apparent rotation generated by pure translation. Square patterns consisting of four segments appear to rotate when they move straightly at a constant speed across the grid background. More surprisingly, the rotations in opposite directions can be generated by exactly the same square patterns. This illusion might be explained by well-known inchworm illusion; inchworm illusion arises at the four segments one after another resulting in the impression of rotation. This illusion is new in the sense that the rotation is generated by pure translation.

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2012 - The Disappearing Hand Trick
Roger Newport, Helen Gilpin and Catherine Preston, University of Nottingham, UK



This multi-sensory illusion uses vision, touch and position sense to create the illusion that the hand has disappeared. The felt positions of the hands are gradually adapted without the participant noticing so that the real locations of the hands end up further outwards than their perceived locations. When the right hand is removed from vision and the participant reaches across to touch it, all they can feel is the empty table. The combined loss of vision and touch creates a powerful illusion that the hand is missing and was designed to simulate loss of awareness in stroke patients.

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2011 - Silencing awareness of change by background motion
Jordan Suchow & George Alvarez, Harvard, USA



Play the movie while looking at the small white speck in the center of the ring. At first, the ring is motionless and it’s easy to tell that the dots are changing color. When the ring begins to rotate, the dots suddenly appear to stop changing. But in reality they are changing the entire time. Take a look.

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2010 - Impossible motion: magnet-like slopes
Kokichi Sugihara, Meiji Institute for Advanced Study of Mathematical Sciences, Japan



In this video, wooden balls roll up the slopes just as if they are pulled by a magnet. The behavior of the balls seems impossible, because it is against the gravity. The video is not a computer graphic, but a real scene. What is actually happening is that the orientations of the slopes are perceived oppositely, and hence the descending motion is misinterpreted as ascending motion. This illusion is remarkable in that it is generated by a three-dimensional solid object and physical motion, instead of a two-dimensional picture.