Swimming Fish Optical Illusion

Swimming Fish optical illusion was originally created by Emily Knight and Arthur Shapiro. It was a 2007 Finalist in the Best Illusion of the Year Contest hosted by the Vision Sciences Society. However, there is a guy called Excel Hero, who recreates optical illusion using nothing but Excel. As he explains, the fish appear to wiggle up and down, but this is again just an illusion – all of the little bastards are actually standing still!

Click Here for a RANDOM Optical Illusion

45 Replies to “Swimming Fish Optical Illusion”

  1. Haha! very niec!:) They do look like they’re moving that’s really nice! =D Awesome

    What’s with saying “bastards” though? a bit out of context lol :P

    1. Dear Barun Vurdlak,
      There are young eyes out there who love this site. My friend’s brother just saw this and bawled his eyes out. Language man!

  2. If you place your mouse on the tip of one of the fish just barely touching it, it clearly moves away from the mouse.. I don’t know what to make of that

  3. It seems to me the more I fixate them the less they move. The ones I don’t look directly at are moving the most. Am I the only one?

  4. Nice effect, but it uses so much of my processor to display it, even in the sidebar gadget. New picture please so I don’t have to keep choosing a different illusion.


  5. It does look like the fish are moving, but just look at the background. HINT:The fish colour moves with the background!

  6. I created the illusion in Excel. I can assure you the fish are not moving.

    The only thing moving is the background. The illusion happens because of the way your brain interprets the moving background shading interacting with the counter shading of each of the fish.

    If you still don’t believe it, go ahead and download the Excel workbook and prove it to yourself:


    My blog is dedicated to teaching readers how to use Excel better and all of the creative workbook examples are freely available.

    I also have a free newsletter that will bring all of my posts directly to your Inbox:


    Kind regards,

    Daniel Ferry

  7. It IS hard to believe the ovals aren’t moving, but do this to prove it to yourself:

    Scroll to a place where you can only see the top third or bottom third of one of the ovals. Scroll to a position where you can only see the lightest or darkest part of one of the ovals. When you don’t see the gradient of the oval, the effect of its movement is canceled.

    Now slowly scroll so more of the oval appears. As soon as you can see both the light and dark portions of the oval, it appears to be moving . . .but you know it isn’t because you just proved it to yourself.

  8. Try looking at it with one eye closed. I only see from one and I saw it immediately. I can stop them by fixating on the fish and also have them change direction !!

  9. Actually they are rotating which contributes to the illusion. Thus rotation is a movement and they are moving but the illusion persists in that they appear to be moving up and down.

  10. Fake! It’s an animated picture! An animation! Try to print screen the picture and put it into Paint.. and see.. there is nothing moving there.. but if it was a true illusion.. those things should have been moving..
    I checked it also with other animation-like-illusion but those were actually working and on paint!

  11. Doros,

    I’m afraid you missed the point entirely!

    Of courset the BACKGOUND is moving. That is what enables the illusion of the fish wiggling up and down.

    THE FISH ARE NOT MOVING. The illusion is that they appear to. This kind of illusion will never work in Paint, or when the image is printed, because those formats do not allow for the background to move.

    The image above is an animated GIF – a screen recording of the illusion working in Excel 2007. The animated GIF has a hard time keeping up with it and as a result the smoothness of the motion is lost. In Excel 2007, it looks much better, smoother. VBA coding is used to purposefully move the background, but none is used on the fish. They are completely motionless. Yet, your brain interprets the visualization in such a way that you are convinced that the fish wiggle up and down.

    Rather than mucking around with paint, just download the original Excel workbook to see for yourself how it works:



    Daniel Ferry

  12. FAKE FAKE FAKE FAKE FAKE This is FAKE If you stop the page from loading all the way you can see that this is just a gif file. a sort video that repeats. Hit the cancel button right next to the refresh button as soon as you see the picture appear. Try it.

  13. If you put a piece of paper on each side of a fish, it proves that they’re not moving; I have just done this.

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