Congratulations to the winners of the 13th annual Best Illusion of the Year Contest! Online voters around the world chose the best illusions of the year from 4pm EDT on October 4th to 4pm EDT on October 5th.

First Place and an award of $3,000 went to “Shape from Motion Only,” a shape perception illusion by Hedva Spitzer, Dana Tearosh, and Niv Weisman of Tel Aviv University in Israel.

Second Place and an award of $2,000 went to “Sky Blue Café Wall Illusion,” a powerful new rendering of the Café Wall shape distortion effect, by the USA artist and magician Victoria Skye.

Third Place and an award of $1,000 went to “Dynamic Müller-Lyer Illusion,” a dynamic reimagining of the classical geometric illusion, by the Italian visual artist Gianni A. Sarcone.

This year’s Contest coincides with the release of Champions of Illusion: The Science Behind Mind-Boggling Images and Mystifying Brain Puzzles. “Champions” features many of the best illusions from the Contest, and their neural underpinnings.

 Credit: Champions of Illusion Book

The Top 3 illusion creators answered a few questions about their illusions (edited for clarity):  

Illusion Chasers: How does your illusion work, and what does it tells us about our mind and brain?

Spitzer, Weisman & Tearosh: The mechanism behind Shape from Motion Only is still an enigma, but there is ongoing research in the field.  Whereas it  is impossible to perceive an object from a single frame, you can see it from a sequence of frames in the video. This remarkable perceptual ability is unique to the human brain (and maybe to other animals’ brains too) and has no parallel in the present technological world.

Skye: The horizontal rows of Sky Blue Café Wall Illusion appear to slant at different angles. Your eyes are playing a trick on you, because the lines are actually straight, and in parallel rows. The rows appear to skew due to the contrast and variations in light and color, as well as to the varying angles of the diamond targets at the intersections. Blurring the image dissipates the illusion by dissolving the contrasts and angles. This illusion shows us that we are easily fooled and cannot trust our perception.  Light and its variances, change the way we see things, or the way we think we see things.

Sarcone: The mechanism of the Dynamic Müller-Lyer Illusion is still open to discussion. The strength of the linear dynamic Müller-Lyer illusion is enhanced when set in a radial arrangement: this layout creates a suggestive illusory spatial pulsation. Though the original illusion has come to be known as the Müller-Lyer illusion, I based my creation on a version of this effect attributed to the German psychologist Franz Brentano.

Radial arrangement of the Sarcone’s Dynamic Müller-Lyer Illusion

Illusion Chasers: Does your illusion relate to any experiences we might have in our daily lives?

Spitzer, Weisman & Tearosh: Ultrasound tests in medicine use real time videos. Common ultrasound images are very noisy, so objects or organs are usually detected better through the movement in the video frames. Thermal cameras also capture an area with hot spots describing static objects, and among them is a live and moving object. Detecting the live object from a single frame is not possible, despite its heat signature. But a  movie will show the live object's movement, making detection possible.

Skye: The Café Wall Illusion shows us that you can’t judge a book by its cover. We cannot take things at face value. This can be applied to teaching moments on how the brain distorts things. For instance, when we judge people at first sight, it doesn’t mean that what you see is the truth.

Sarcone: Many geometric illusions involve V-shaped lines… You can see similar effects in fabric patterns (Zöllner illusion), in the moon illusion (the moon appears larger in the horizon due to Ponzo illusion effect), in the distribution of a line in a closed space (Sander’s parallelogram), etc. A similar illusory effect applies also to time perception: time that is filled with activities (compacted line with arrow heads pointing outside) seems shorter than empty time, when we have nothing to do (unwrapped line with arrow heads pointing inside).

Illusion Chasers: How did you discover your illusion?

Spitzer, Weisman & Tearosh: We discovered our illusion through our work on computer vision with infrared (IR) images. We noticed that in IR movies we could detect an object from its movement, but not from a single frame. We combined this observation with our previous knowledge about ‘shape from motion’ phenomena to create Shape from Motion Only.

Skye: I love the classic Café Wall illusion and how the brain is tricked into seeing crooked lines that are actually straight. I had noticed, while creating multiple versions of this effect, that the illusion would completely dissolve when my vision became blurred. I experimented with different ways to blur the image or bypass the contrasts of the colors and sharp angles. I created a GIF that showed the blurring in stages, to see the complete transformation from slanted to parallel. It’s quite fascinating to see how your eyes and brain can be tricked so easily.

Sarcone: I hold many optical illusion workshops around Europe. About two years ago, I presented the Müller-Lyer illusion to children, using a hands-on exhibit of my creation. The exhibit consisted of a simple metal board onto which was painted a line with three red dots: one dot in the middle of the line, and the two other dots at its ends. A sort of clock hand could be pivoted at each dot, to empirically experiment the illusory increasing or decreasing of the segments. To my great surprise, some children played nonstop with the thin revolving hands of the exhibit, mesmerized by the illusory effect. That experience prompted me to create an animated version of the Müller-Lyer illusion.

Illusion submissions are now accepted for the 14th edition of the Best Illusion of the Year Contest, to be held in 2018.