Lesson #1 Illusions

Please click here to print out the illusion worksheet

We have studied about observations and using the five senses to make careful observations. Scientists have determined that learning in humans comes from the following senses:

sight 83% hearing 11% smell 3.5% touch 1.5% taste 1.0%

Notice that the first three senses are remote senses, which means that the object being observed does not have to come in direct contact with the observer. What is the total amount of learning that comes from these three remote senses?

Illusions occur when one or more of our senses has been fooled. Our eyesight is by far our most important sense, and so optical illusions are the most common type.Click here to see how this can happen. Now that you know a little about illusions, click here to view some more.  Now try another!

Optical illusions can be classified into many general categories. One of these is called an afterimage. After staring at an image for about 30 seconds, your eyes become desensitized (or tired). The constant signal is then ignored by the brain. When you look away from the image, your brain has "turned off" this signal and the reverse image will appear. Click here to try an afterimage.

Another type of illusion is an impossible object. Although an impossible object initially looks normal, upon close observation, you will notice that your brain has tried to make sense out of an impossible object. Click here to see examples of impossible objects.

Illusions also come in a form called ambiguity. In these illusions, your brain must choose which interpretation is correct. Often times, it cannot and the images will flip/flop from one interpretation to another. Try some here! Try Another!

Distortion illusions are ones which alter an image's size, shape, and length. Often times, a funhouse will use these illusions to confuse your perception. Click here to view one type of distortion illusion. Here's another!  Try Another?  How about one more?!

Animals and plants use a type of illusion called camouflage. This illusion allows them to blend in with their environment. Often times this is most effective if the animal does not move. Click here to see an example of camouflage!

An important artist who has combined his artistic talents with optical illusions is M.C. Escher. One of his drawings depicts a hand drawing another hand. Click here to view it. M.C. Escher combines a distortion illusion with an impossible object in several of his drawings. Click here to view one. Now, find out more about M.C. Escher by clicking here.

Now that you're done, you can play with the Escher sketch!

If you have any time left, here are some fun places you can go:

Cool Optical Illusions


The Hall of Illusions

Seeing, Hearing, and Smelling the World

Fechner Color Illusion

Grand Illusions

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