Optical Illusions
v1.0
Directions
It’s pretty straight forward… :-P However, just a tip… some of the examples have a lot of
white space around them. I recommend cutting most of the white space out so it doesn’t
look too empty. Maybe back them with construction paper or something.
Comments
I’d be more than happy to hear what people think of this. E-mail comments, questions,
marriage proposals, and lawsuit notices to: jbarron1@ksc.mailcruiser.com Oh, and if you
don’t mind… e-mail me if you use it so I know where it ends up. Just curious! 
“An optical illusion is characterized by visually perceived images that, at least in
common sense terms, are deceptive or misleading.” –Wikipedia.org
Most people have seen an optical illusion at some point in their lives. Maybe it
was a geometric shape that would be impossible to replicate in reality… maybe
you’ve seen shapes appear to move as you stare at them on a sheet of paper... or
maybe you’ve seen colors changing as you look around an image.
There are tons of optical illusions out there; but have you ever wondered what
makes them optical illusions? How do they work? How can you see something
you know doesn’t exist?
Well, I’m not going to dig into the scientific reasons for it all… but I’ll give a brief
definition, then lots of examples that you can scratch your head at.
Physiological optical illusions are the kind that occur after staring at a bright light for
a few seconds. The theory is that they result from an over-stimulation of certain
neurological pathways in the brain. In other words, if you over-stimulate your vision
by staring at a bright light and then close your eyes, you’ll “see” an afterimage of that
light.
Cognitive optical illusions can be broken down into a few categories:
•Ambiguous: Cause a change in perception due to multiple interpretations.
•Distorting: Appear to distort an object’s size, length, curvature, color, etc.
•Paradox: Images/shapes that could not exist in reality (impossible objects).
•Fictional: Illusions that literally don’t exist (aka Hallucinations).
Stare at the flag for thirty seconds, then quickly look at a blank wall or
white piece of paper. What do you see?
This is an example of a physiological optical illusion.
Can you tell which orientation the wire frame cube is?
 OR 
This is an example of an ambiguous cognitive optical illusion.
What is this a picture of?
Faces or vases?
This is an example of an ambiguous cognitive optical illusion.
Are the horizontal lines straight and parallel, or curved?
This is an example of a distorting cognitive optical illusion.
Which line is the longest? Shortest?
Hint: Get a ruler… check them out.
This is an example of a distorting cognitive optical illusion.
Hey architecture majors, let’s see you make this:
This is an example of a paradox cognitive optical illusion.
I’d love to see someone try to get to the top.
This is an example of a paradox cognitive optical illusion.
Focus on the four dots for 45 seconds, then quickly look at a wall and blink.
This is an example of a physiological optical illusion.
Which square is darker? A or B?
This one blows me away… they’re the same shade!
This is an example of a distorting cognitive optical illusion.
Can you find the black circles?
Hint: There are no black circles 
This is an example of a distorting cognitive optical illusion.
In the middle bar, is the left or right side lighter?
Yet again… blows me away. Try covering up the outer gradient and focus on the middle line.
This is an example of a distorting cognitive optical illusion.
Look at the black dot as you move your head backward and foreward.
Do you notice anything rotating?
This is an example of a distorting cognitive optical illusion.
The internet is full of websites containing optical illusions. Some even sell
books full of them! The examples and definitions that I’ve used can be found at
the website listed below. The site also has numerous links to other famous
illusions. Enjoy!
http://en.wikipedia.org/wiki/Optical_illusion
“Reality is merely an illusion, albeit a very persistent one.” –Albert Einstein