‘Rotating Snakes’ optical illusion

I like optical illusions, such as the Ponzo Illusion, which is one of the better explanations of why the full moon on the horizon seems so big. They provide nice examples of the complex interplay of visual sensations and brain activity and cautions us that what we ‘see’ may not be really what is out there.

Here’s another really one called ‘Rotating Snakes’. Notice how different parts seem to rotate depending on the direction of your gaze.

Carl Zimmer provides the explanation for this illusion.


  1. JustKat says

    I love stuff like this.

    Whichever circle I’m looking at is still while the others appear to move, but if I look (stare) at the middle of the upper two circles (the place right above the point of the center diamond) for more than a couple of seconds everything stops, or slows almost to a stop.

    Now I feel a little sick…

  2. JustKat says

    jamessweet – I looked at your link. I don’t understand the lines being the same width – I measured with a ruler both length and width and they aren’t the same width.

    The color gradient and the one that claims the colored blocks are exactly the same – I actually took post-it notes and blocked off all color around the blocks. The gradient is actually there and the colored blocks are different colors.

    The last picture that shows the penguin and pig asks if you can spot the pig. It’s there as plain as day.

    Most of the time when I test illusions like this I can actually see that the colors are really the same, or length is the same, etc. by using a ruler or blocking surrounding color…

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