The Illusion Only Some People Can See

The Illusion Only Some People Can See

Ames window illusion illustrates how we don’t directly perceive external reality. Special Holiday deal! Go to and use code VERITASIUM to get 68% off a 2 year plan plus 4 additional months free. It’s risk free with Nord’s 30 day money-back guarantee!

Special thanks to:
Prof. Phil Kellman from UCLA Psychology
Museum of Illusions in Los Angeles for the use of their Ames Room
Curiosity Show – Video on Ames Illusion:

Ames, A., Jr. (1951). Visual perception and the rotating trapezoidal window. Psychological Monographs: General and Applied, 65(7), i–32.

Marcel de Heer & Thomas V. Papathomas (2017) The Ames Window Illusion and Its Variations

Oross, Stephen, Francis, Ellie, Mauk, Deborah & Fox, Robert. (1987). The Ames Window Illusion: Perception of Illusory Motion by Human Infants. Journal of Experimental Psychology: Human Perception & Performance, 13(4), 609-613.

Behrens, R. (1987). The Life and Unusual Ideas of Adelbert Ames, Jr. Leonardo, 20(3), 273-279. doi:10.2307/1578173

Burnham, C., & Ono, H. (1969). Variables Altering Perception of the Rotating Trapezoidal Illusion. The American Journal of Psychology, 82(1), 86-95. doi:10.2307/1420609

Allport, G. W., & Pettigrew, T. F. (1957). Cultural influence on the perception of movement: The trapezoidal illusion among Zulus. The Journal of Abnormal and Social Psychology, 55(1), 104–113.

Zenhausern R. Effect of Perspective on Two Trapezoid Illusions. Perceptual and Motor Skills. 1969;28(3):1003-1009. doi:10.2466/pms.1969.28.3.1003

Gehringer, W. L., & Engel, E. (1986). Effect of ecological viewing conditions on the Ames’ distorted room illusion. Journal of Experimental Psychology: Human Perception and Performance, 12(2), 181–185.

Long, G.M., Toppino, T.C. Adaptation effects and reversible figures: A comment on Horlitz and O’Leary. Perception & Psychophysics 56, 605–610 (1994).

Gregory RL. Looking through the Ames window. Perception. 2009;38(12):1739-40. doi: 10.1068/p3812ed. PMID: 20192124.

Jahoda, G. (1966). Geometric illusions and environment: A study in Ghana. British Journal of Psychology, 57(1-2), 193–199.

V. Mary Stewart (1974) A Cross-Cultural Test of the “Carpentered World” Hypothesis Using The Ames Distorted Room Illusion, International Journal of Psychology, 9:2, 79-89, DOI: 10.1080/00207597408247094

Margaret Kathleen Cappone (1966) The Effect of Verbal Suggestion on the Reversal Rate of the Ames Trapezoid Illusion, The Journal of Psychology, 62:2, 211-219, DOI: 10.1080/00223980.1966.10543786

Researched and written by Petr Lebedev and Derek Muller
Filmed by Derek Muller and Raquel Nuno
Animations, VFX, and Music by Jonny Hyman
Ames Room VFX and additional Ames Window animation by Nicolas Pratt
Additional Music from “Life in Color” “Singularity”
Large Ames window construction by GW Construction
Video supplied by Getty Images


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  1. When watching with the ruler, or when focusing after some ruler practice, the window starts to go backwards, then flips to reconcile with the ruler, then flips backwards again as it passes being edge-on to us. I cannot for the life of me get it to make a full revolution in the correct direction.

  2. That is cool I had a hard time telling After learning going around I kept seeing the window swings. Only twice I saw it go around but when I went back again it did appear to swing back and forth. I am totally interested in playing with illusions a lot of illusions I can see both ways like vase versus two faces or paper foldein or out those are just two. Brenq

  3. You can see the reflection of light glide across the shaded areas of the smaller window, and it broke the illusion for me, but i did have to focus on it lol

  4. I can sort of see it rotating but when it appears to go the other direction I question what I'm seeing. A good way to see it is to look at the small end.

  5. I finally saw it rotate fully.
    What is creating the effect are the blue painted lines on the ends, causing the illusion of thickness, when in reality it is paper thin.
    Focus on the ends, particularly on the bevelled corner, telling yourself that
    the image has no thickness, ignoring the blue lines, and perhaps you will see the rotation.

  6. It's a little easier to see whats going on if you look at the red version at 5:02 .
    The card is slightly bent so if you focus on that curved edge, you can follow it all the way around.

  7. I think is nice how my brain gets fooled by the illusion, but after a while it "learns", so I can see both (the illusion and the reallity, the oscilation and the rotation). It happened to me the same with the two color dress a long time ago (golden/white, blue/black). After knowing the truth, my brain "learned" and I could correct the light experience to see both colors as they were.