Astonishing optical illusion.

That one is very strange,The little squares are rotating,but I cannot figure why this has such an effect. One reason not to believe everything you see. I recall an image that when you first looked at it,it was one image,but then if you de-focused a little,like looking through a reflection on the water, it became a 3d image,but I cannot find on on line.My favorite one was the star ship Enterprise. Perhaps SE can help find it?He is the Guru of Google.

What I meant to say was that the 6 sided polygons between the dark blue lines has 1 side shorter than the opposite side,or is off center.The shorter side alternates every line.The eyes tend to follow the shorter side of the polygon to the converging dark blue lines,and follow the longer sides to the diverging lines.This creates an illusion of non parallel lines.

This is a common test used by Opticians when observing Astigmatism. A childs game with a real life purpose.

I printed it out and measured them.

They all appear to be the same size.

Of course,appearances can be deceiving.

I'm trying to get my wife to make me a quilt like this...

Thank you: I think you're right.

If you squint your eyes, the lines all go back 'parallel'.

The lines are parallel to each other,but not to the edges of the page.Also the parallelograms in the middle changes from one offset center to the other in alternated lines.This must be what the brain locks into.The eyes tend to follow the converging and diverging lines of the parallelograms in the middle.

This stretched hexagonal figure also bulges back and forth, these two elements I believe facilitate the illusion..

Good observations by everyone. Once you've identified the patterns and detailed features that cause these visual perceptions, it probably wouldn't be difficult for a good graphics/imaging programmer to write software that would mass produce these things.

I wonder could you compose a picture of something just from optical illusion...?

Like my OP I've seen similar ones to this but none as good.

I wonder why it doesn't seem to work when it's printed.

I suspect it's the contrast, black blacks and white whites....

This is one of those optical things that could give me a migraine.

If you look at it from the side, where you can't see the diamond star off-set, the lines straighten right out. It's a superposition of parallels.

Interesting effect. You definitely have to be at regular viewing distance from your screen so your brain to process the details of the different elements and fool you. Start backing away and by 10 feet or so, it just looks like a set of parallel bars.

I have seen women that look like that---they look better at a distance....

You have to be about 3' back to see it....

Repeated CTRL+- and sit back a bit also works.

If you squint your eyes you can see it at the normal distance.

The orientation of the four black and white diamonds trick the brain. Where the black diamonds vertically face each other with the white diamonds horizontal, the adjacent black square is perceived to be shorter while the adjacent light-colored square is perceived to be taller. Move over to the adjoining portion with the black diamonds are horizontal and the white diamonds vertical, the adjacent black square is perceived to be taller while the adjacent light-colored square is perceived to be shorter. Thus, each larger square is perceived as shorter on its left end and taller on its right end. Yet, all lines are of identical lengths and all horizonal lines are parallel. Very effective illusion. This is similar as a perception problem to the one where one sees a small red area and a nearby small blue area on a neutral background, with one appearing to be in front of the surface while the other appears to be behind the surface. --JMM