Monday, April 22, 2013

Optical Illusions and their role in Education, Brain Training, and Visual Literacy

Aside from being fun, optical illusions actually play a role in education and in visual literacy.  They help illustrate that we see by learning to see.  While our brains relay information taken in through our eyes, we learn to interpret what we see by recognizing and storing patterns we learn as we continuously interact with the world around us.  These patterns enable us to identify faces, dangers, friends, directions, routes, and opportunities around us.

[SPOILER ALERT:  This post will detail how we learn to see and illustrate the power of optical illusions...but if you don't have time for all of it, skip to the final video clip which will blow your minds - at least it blew mine.]

Understanding Optical Illusions and the Power of Visual Literacy:
When learning to see, read, or interact with the world around us, context is integral to understanding.  Context helps prime the brain to anticipate what is coming, usually making processing faster and more efficient.  We do this all the time with reading.  While research now shows that we 'look at' and process each letter as we read, our brains process the shape evaluating "probable' letters and constructing 'probable' words and content.  This is why it is so important to preview new materials when teaching. When we our brains 'think' it is one letter or word and it doesn't make sense, more attention is given to the visual cues and reading slows down. Context is also essential when viewing/interpreting images and it is context that creators 'twist' with optical illusions.

Here's how CONTEXT helps us learn how to see:
You can take identical squares and surround them in different colors and they will 'look' different. In this example, the surface color of squares A and B are identical.  Cover the seam where squares A and B meet, and you'll see (wait a few seconds for your eyes/brain to adjust).
Identical Colors
For more on color and the "context" different colors relay, please go to:

But, there's a lot more to context and learning to see than color cues.

Gestalt theory addresses many of these issues formulating that the unified whole of an object we 'see' is more than the sum of its individual parts.  Gestalt theorists originally identified five key principles (and later added a sixth) that influence how we 'see' when we look at images:
    old or young woman?
  • Figure/Ground - we tend to separate forms in an image, focusing on "dominant wholes" while pushing other parts of the image into the background.  We do this with the optical illusion of the "old hag/young woman" for example.  In this image we can push the old hag's face and white hair forward or place the young woman's brown hair and hat with feather forward pushing the old hag's features in the background. Camouflage works under this principle as well.  The material's meandering lines of mottled-colored patterns disrupt our brains by trying to hide the contour or outline of the body or vehicle.  

Another very famous example by Edgar Rubin, the "Rubin Vase" is one of the most well know demonstrations of how the figure-ground relationship works:  In this case, the image changes depending on whether we focus on the faces or the vase.
  • Proximity - we tend to group objects together based on their placement or proximity. So, objects or shapes that are close to one another appear to form groups.  Fruit in a bowl is perceived of as "fruit" and not "one banana, one apple, one apple, grapes, one orange, and one more apple." In the example above, the proximity of dots and dark spots become a 'dog':
  • Similarity - we tend to perceive forms with similar characteristics (size, color, shape, etc.) as a group. The more alike the items are, the more likely they are to form groups. As dissimilar as they are, our minds will conversely resist grouping them together.  In the image here, there are two different shapes that are grouped to form a pattern. We group the squares together to form a cross surrounded for four groups of circles.  In this case, the square is the figure and the sets of circles are the ground.
  • Closure - we tend to 'fill in' information in images which appear incomplete to us.  We do this when reading or writing (and unfortunately sometimes when editing): we often won't recognize if letters were missing because we tend or prefer to see words as complete entities and not as individual letters. Scott McCloud (Understanding Comics) discusses how our brains automatically want to make shapes into human (or recognizable) forms.  In the image here, we see the swirls of 'people' as a tree because our minds focus more on the continuous 'movement' of the people, and close them into one complete image
  • Continuance or Continuity- we tend to continue shapes beyond their ending point as the edge of one shape will continue into the space and meet up with other shapes or edges of the picture plane. Continuance in the form of a line, an edge, or a direction from one form to another creates a fluid connection among compositional parts. Here are three factors that contribute to continuance: 
    • Perspective
    •  Eye direction of a subject - if an object in a photo or image is looking in a particular direction,  our eyes will follow the gaze of that subject;
    •  Paths or rivers draw effectively use 'line' to draw the viewer's eyes in a particular direction. 
In the image of the 'tree' above, continuance is involved as the images of 'swirling' continue into each other to create the tree.  Perspective and continuance work brilliantly in this photograph found at In this photograph, the causeway forms a line of continuity, drawing the viewer's eyes to the group of trees in the background.
  • Some have added a sixth principle of Symmetry - when we perceive objects we tend to perceive them as symmetrical shapes that form around their center. Furthermore, the principle of symmetry work particularly well when framing photos and images. People are accustomed to receiving information in a systematic and organized manner and tend to avoid material that requires too much work to process and comprehend.  A symmetrical design will create a sense of equilibrium and balance while an asymmetrical design will cause tension. Often, however (especially with images), the tension created makes the image more interesting and less 'boring'(see the photo below).  The goal is to structure you images (and your text) to be easy to follow but not overly predictable and engaging with some nuance, twist, or hook to keep your audiences attention.

NOTE that while I have given you visual examples of each of the gestalt principles, many images use multiple principles to successfully work as optical illusions.

For fun, here is a link of optical illusions in photos from Bored Panda with some of my favorites below:

 1. Camouflage art by Wilma Hurskaninen (link)

2. French landscape astrophotographer Laurent Laveder shows how some simple props and a bit of imagination can turn the moon into anything you like. (link)

3. A work by Japanese artist Makoto Aida titled AZEMICHI (a path between rice fields). (link) which clearly illustrates the principle of continuance.

The artist Maurits Cornelis Escher is famous for his optical illusions which integrate most of the gestalt princiiples:

Relativity, 1953

 Drawing Hands, 1948

But there is even more to learning to see than gestalt and color... some images become so familiar and universal, they become symbols or icons. Just the way we learn to use the alphabet and sight words to help us read, we use icons, signs and symbols to help us see. A car's dashboard, for example will show an icon to tell us to change the oil, close our doors, secure our seat belts, when we need gas (and on what side of the car we will find the gas tank) and so much more:



Playing with optical illusions provides us with experience in learning HOW to interpret complex images.  The more we experience, the more flexible we are in interpreting what we see.

A rabbit, looking right? Or a duck, looking left?

The Hering illusion is an optical illusion discovered by the German physiologist Ewald Hering in 1861. The two horizontal lines are both straight, but they look as if they were bowed outwards. The distortion is produced by the lined pattern on the background that simulates a perspective design, and creates a false impression of depth. Note that the thinner line appears more bowed than the thicker line.
Hering illusion

In closing, here is a literally 'mind-blowing' video illustrating HOW are minds are trained to interpret images a certain way, and how confusing it is for us when we 'see' one thing but our mind 'understands' what we see in another way entirely.  Below is a video that the mind (at least my addled mind) just can't grasp - illustrating how important the 'literacy' segment is of visual literacy

For more fun, brain blasting and brain training please visit these cites:
Thanks for your visit this week.  Please leave your favorite optical illusions or any other reactions, suggestions, and/or questions in the "Comments."


  1. Thanks for the interesting read on optical illusions. I pinned a few of the pictures.

  2. Meryl, I think you have outdone yourself on this post.
    I found it fascinating and the video at the end really explains the theory.
    Thanks so much.

  3. Marvellous, very interesting. I absolutely admire the works of Escher!

  4. Awesome post! I love optical illusions and it was interesting learning more about them.

    An Arkies Musings

  5. Tremendous amount of information. I think everyone is fascinated with OPTICAL illusions. Kate, ABC Team

  6. I had seen that last video before; it's almost hypnotic.
    Seems that false perception plays into a lot of our biases, unfortunately.

    ROG, ABC Wednesday team

  7. When I taught 4th graders, we studied light and had a lot of fun with optical illusions! Love that video - I think it's gone viral on the net!

    abcw team

  8. Very interesting subject,Meryl! I liked the video at the end. And the drawings by Escher. I have a book about his life and a movie as well.I am a fan of his.
    Thank you for sharing.Have a wonderful week.
    Wil, ABCW Team.

  9. Meryl ~ you always have fascinating and educational posts ~ Wonderful for O ~ ^_^

  10. Such an interesting post!
    Happy WW :)

  11. Interesting photos. I still do not see squares A & B being the same color.

  12. I've always enjoyed these types of illusions, yet it had been some time since I had seen some, thanks for sharing and bringing back so many great memories.
    Thanks for linking and have a happy WW.

  13. Optical illusions are so cool! In New Zealand I visited an entire museum dedicated to them. I think it was called Puzzling World. It was pretty cool!


  14. Those optical illusion posters that were popular a few years ago were a puzzle to me. Try as I would I could not make the 3-D picture embedded in them appear. In addition I will sometimes walk in to a room where the TV is on and when I look at the screen I can't make sense of the picture for a few seconds. It's like looking at a mixed up jigsaw puzzle. I think partly I have a depth perception problem. Interesting though.

  15. What a wonderfully informative post! thank you. I have bookmarked it for a return visit soon. I appreciate the effort you took on behalf of the rest of us!


  16. Those are very neat!


    Over and over again, I am always late commenting, but, trying to catch up.
    Rose, ABC Wednesday Team.

  17. Very interesting post. I look forward to more; love the subjects you cover.

    Best wishes, Kennedy Creative Works

  18. THese are cool! I love optical illusions that plays with the eyes. I’ve always wanted to do something like these but never got around to do them.

  19. Great way to brain torture! ;)
    But I've always enjoyed these types of illusions.

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