Dynamic Optical Illusions

Where nothing is as it seems.

An intriguing selection of old, new and exclusive optical illusions. Pictures are often enhanced via the use of 3D and through animation.

Even though a few of the optical illusions here are already popular, I have enhanced many of them by animating them in some way - rotating, squashing, switching, sliding - you name it. Also, many of the optical illusions on display I've actually made myself =) (including...
The "Rotating Dot Whirlpool", "Tube of illusion", "Vision distorter", "The multi-square slicer", "Tube of Illusion", "Glowing Core", "Wheel of Confusion", "Eclipse of Mars", the "Bulb Swap" thing and to some extent - the "Optical Blind Spot", "Tri-lock", "Crooked Skyscraper", "Multi-cube", "Flickering Fog" and "Magic Zoomster")

Out of interest, if anyone knows the names of the people who made some of the optical illusions on this page, then email me or visit the forum - so I can give credit.
For more fabulous optical illusions like these, visit the excellent sites http://www.eyetricks.com/ and Exploratorium's site of interactive optical illusions. Alternatively, you might like to see the
3-D optical illusions (pictures in stereo) at the Skytopia 3D Stereoscopic gallery

optical illusions 1 At first, there doesn't seem anything unusual about this picture. I mean, it's just a bunch of diagonal lines and a slightly distorted square in the middle - right? Wrong.
Believe it or not, the 4 lines that make up the square are actually perfectly straight. In fact it /is/ a perfect square. For proof of this, the animation will swap between the two frames so you can see the square remains the same. Also check by loading the pic into your favourite art package.

optical illusions 2
Rotating dot whirlpool
Wow! Try staring at this for more than 5 seconds
without going crazy. Then try following it round! =)
Curves constantly die out and then re-evolve as
part of another curve.


Each of the 3 curves shown below are sections of the circle.
Which would form the largest circle though?
Answer at the bottom of the page.
optical illusions 3

optical illusions 4

Skewed lines

All these tracks look as though they've come from a broken down railway track, but in actual fact, they are perfectly parallel! To prove they really are parallel, watch the small 'hairs' gradually disappear. You will see the lines as how you would expect them to be.

Primrose's field (right)

This amazing illusion to the right was created by Akiyoshi Kitaoka. It already looks quite 'wavy', but try slowly moving the mouse cursor up and down the center of the image - and focus on the cursor. You should see the picture 'waving' in an incredible way.

Visit his Anomalous motion illusions web site
for more illusions in this style.

A Bulge

Also created by Akiyoshi, the lines in this picture below are completely parallel would you believe?

What does this simple green signpost say?
Guess again.
Look at the bottom of
the page for the answer.
optical illusions 5
optical illusions 5

Multi Cube

Now this is very clever, even for those who think they know what's going on here. Take a look at the diagram - how many cubes can you see? You can give 1 or 2 answers, but you are not allowed to count 'overlapping' cubes as part of any one total. As soon as you think you know the answer/s, click the picture for the full optical illusion and be amazed.

optical illusions 6

The glowing core

Look into the centre (white point) and stare for a while. How many colours can you see altogether in the object? You should see a purplish circle... and the 4 rotating 'wings' are tinted green. Make sure you always keep focused on the centre.
Once you've done this, read on...

Are those four wings really green? Amazingly, they are exactly the same colour as the circle inside. Don't believe me? Well try following one of the wings round. You'll see that the colour matches the inner circle perfectly.

NB. The faster the circle rotates, the better the illusion will work. Unfortunately, Explorer has great trouble displaying GIF animations faster than about 10 frames per second, so I suggest saving the anim and then using an external such as Irfanview. Visit http://www.irfanview.com/ for more details.
If you would like to see an animation similar to the one on the left (but this the time, the corners glow), then click here
optical illusions 7
What line is longer;
from a to b, or from b to c?

Amazingly, they're both the same length. This is perhaps the most extreme example of I have found that distorts perception of length.
optical illusions 7 Which semicircle is brighter - the left or the right half? optical illusions 8
Can you see dark blotches on the white 'junctions' in between the corners of these black squares?
optical illusions 9

Green Fade illusion Another illusion I created, or rather discovered accidentally, but you'll need to have your PC in 24 bit colour to see it properly. It looks as though the green bar above is getting lighter further to the right. But in actual fact, it's exactly the same shade on the far right as it is on the far left..... "Light Green" really does equal "Dark Green"!

optical illusions 9
Above: (The Multi-Square Slicer) (Once again, this looks more impressive using the Irfanview player...
Right: (The Shimmering Dots) Do you find that the white dots shimmer? (illusion originally discovered by Elke Lingelbach)

The Eclipse of Mars - See a new colour you've never seen before!!

...Well... at least never before on your monitor. This illusion has been voted the greatest optical illusion in the poll, and also appeared as illusion of the month at Amos Storkey's Illusion page
If the 'Glowing Core' didn't work for you, then this one surely will. It's a startling example of how poor the green/cyan element is on TVs and monitors generally. The colour you are about to witness is actually true Cyan ... a colour that is heavily diluted on the vast optical illusions 10 majority of monitors (thanks to colour pollution). It's a pity one needs an optical illusion to demonstrate this, but at least you can see what you've been missing ;-) Anyway on with the illusion....
Stare at the white dot in the centre of the red circle. The longer - the better (two minutes and you'll get a much stronger effect). Always try to keep focused on the white dot. It'll be worth it.
Soon after staring, you'll start to see a thin rim of light around the edge. Don't stop staring though yet! Wait another minute - keeping your head perfectly still.
Once you've done this, slowly - move your head backwards - making sure to keep your eyes focused on the dot at all times. The circle's rim will glow brilliantly with true Cyan! Keep on moving your head slowly backwards, and it'll glow very hot!...
You've seen the illusion - now hear the music!
Click here
The blue/cyan colour chart to the right isn't part of the illusion, but there to demonstrate that the ultra cyan you have just seen is not in the monitor's color palette! It should be, but isn't.
It's an amazing effect and something I created whilst researching the problem with monitors and their inability to display real cyan. These 2 colours (red and this exact shade of cyan) work better than any other colour combination for many reasons, but click here for the ultra-brilliant green version - 'Eclipse of Triton'.
Also visit Skytopia's very own Light and Colour trivia page which speaks about and demonstrates effects similar to this illusion.


(left) The Crooked Skyscraper.
All of the red lines are completely parallel would you believe?

Tube of illusion

OK, this one really belongs in the Skytopia 3D stereoscopic gallery, but I just couldn't resist. If you can cross your eyes, so that both pictures slide 'into' each other - to form a third, 3D image between them, the effect you will see is truly stunning!

Try focusing on something in between you and the monitor to help see the illusion. If you're still stuck and you really want to see the illusion, try this site to help practise seeing 3-D stereo.

If you can't manage to see this cross eyed version below, then try the parallel version here. For this parallel version you look behind the monitor and just like the cross eyed version - try to get the two tubes to match up. Unfortunately though, it needs to made around four times as small due to the nature of parallel vision.

optical illusions 11

Wheel of Confusion

Which way is the wheel turning!?
Focus on the red dots and follow them round... it appears to be rotating anti-clockwise. However, if you follow the yellow dots round instead, the whole wheel will be turning the other way! - clockwise!
optical illusions 12

optical illusions 13

Magic Zoomster

This cool optical illusion has been seen before, but I've spruced it up by adding colour, multiple layers, and making it bigger!! The idea is to focus on the dot in the centre and then move your head constantly towards and away from the monitor. You should see the circles rotate spookily! Press the F11 key in your browser to see the illusion at full screen!

For more illusions similar to this one, visit Akiyoshi Kitaoka's Rotational illusion page.

Flickering Fog

Based on an illusion by
Akiyoshi Kitaoka

Just like you did for the Eclipse of Mars, stare intently at the red dot in the center of the left block for about a couple of minutes.
Once you've done this, look over to the center of the right block. It should act weird - by fading out and 'flickering'. If you move your head closer and further from the monitor (while focussing in the center), you should see some interesting interference effects too.

Checker Shadow Illusion

This fantastic illusion was created by Edward Adelson.
Incredibly, both A and B are the same shade of grey. The illusion plays tricks on the mind partly thanks to the dark shadow contrast around B - but also due to the bright white background contrast near A.
With some 'training', it is possible to see both A and B as the same shade, but otherwise you might want to import the picture into a paint package to prove it to yourself.

Rotating snakes

Kitaoka's best illusion in my opinion. It will be interesting to see if it overtakes the 'Eclipse of Mars' illusion in poll votes.
For more illusions like this, visit his Rotating Illusions page.

Find your blind spot

Another popular one - and quite unnerving if you've never seen it before...
Close your left and eye and just focus your right eye on the tiny cross. At some point the big circle will disappear as it crosses your 'blind spot'. If you can't see this effect, then try sitting closer/further from the screen.
optical illusions 14

Vision distorter (v2.0)
Watch your very world around you distort!

If you've downloaded the 'Microsoft Video 1' AVI versions zip, first unzip it and then open one of the four extracted anims through Windows Media Player. Now you'll need to loop the animation. If you're using Windows Media Player 7 or higher, then simply select Repeat (Ctrl T) from the Play pulldown menu.

If you're using Windows Media Player 6 or lower then select "View > Options" from the pulldown menu, and then click the "Repeat forever" button in the Playback area.

Once you have the animation running, you'll want to make the picture as big as possible (processor power permitting) for maximum effect, so select "Full Screen" from the view menu (or press Alt+Enter).
Seeing is believing..... or so they say. Well believe it no more, because as these animations will show, your very world is going to distort around you!
Improved over time, this ranks as one of the more scary optical illusions. There are anims to make everything shrink, grow, stretch, and a mix of these.

For this stunning illusion, you'll want to download this small and easy to install ultra-efficient AVI lossless codec created by Kenji Oshima. Otherwise, you may download the standard "Microsoft Video 1" AVI versions here (20k zipped), but then you'll need to follow the instructions in the blue box-out to the right.

INSTRUCTIONS: After clicking on the box of your choice (install that codec first), sit up fairly close to the monitor screen and stare into the center of the animation for a minute or 2 (the longer the better). Once you've done this, look at something else, and your vision will go haywire! Things will really look as though they're shrinking or growing!


Grow + Shrink!



optical illusions 16
There's certainly something very ambiguous
about which way this is meant to be up...

Bulb swap
This is really what goes on in light bulb factories by the way

Survey: After looking at the Illusions on this page, what is your favorite optical illusion? You may select up to 3 choices
Rotating Dot Whirlpool
Tube of Illusion
Vision Distorter
Multi-square Slicer
Glowing Core
Wheel of Confusion
Skewed Lines
Crooked Skyscraper
Checker Shadow
Flickering Fog
A Bulge
Rotating Snakes
Primrose's Field
Eclipse of Mars
Bulb Swap
Optical Blind Spot
Magic Zoomster
Shimmering Dots
Ambiguity Rotation
Paris in Springtime
Green Fade

Comments (optional)

or see results!

The ideal numbering system - base twelve.
The numbering system that everyone uses - based on 10 - is a somewhat arbitrary kludge. Everyday calculations and world economy would improve if we all switched to the dozenal numbering system - based on the brilliant number 12. See this site for more information.

optical illusions 17ANSWERS (to earlier illusions)
Tri-curve: They're all the same size
Sign says "I love Paris in the /the/ springtime".
The word "the" is repeated.