Katharine has been writing essays and articles since her school years and enjoys finding challenging topics to write about and explain.
Two Faces or a Vase?
What Causes Optical Illusions?
We all know how amusing a good optical illusion can be. Somehow, it's fun to trick our brains! And that's just what it is! An optical illusion occurs when the true elements of an image are misinterpreted by the brain, and the viewer sees something different than what is actually in the image.
There are various reasons why this happens, but they fall into two general categories.
1) Some are physiological phenomena, having to do with the interaction of the eye and the brain. Certain combinations of motion and color can be overstimulating to the brain. The brain then tries to organize the images in a way that makes sense. In the case of an optical illusion, this effort to order its perceptions results in the brain over-riding the messages coming from the eye, which results in you thinking you see something that, in reality, is not there.
2) Others are cognitive, which have to do with pre-conceived ideas that you have which have "trained" your brain to look for some things over others. The famous faces or vase optical illusion is one example. Some people immediately see the vase in the picture above, while others see only the silhouettes of two faces. The reasons why people differ in these perceptions is a mystery, but it probably has to do with a complex set of ideas and basic beliefs that you hold, which encourages the brain to "see" what is most relevant to you in these ambiguous images.
Here is a pretty good explanation of what causes optical illusions with examples:
How do optical illusions work?
Here we will look at some more optical illusions. See if each one works for you or not. Perhaps your brain can't be fooled?? Try these examples of optical illusions and see for yourself! (you may click on images 2 and 4 to make them bigger and more effective)
1. We'll start with a simple but tricky one. Take a look at this cylinder. Are you looking down into the cylinder, or up into it from below? Can you change how you see it? Can you change back to the first way you saw it?
2. Here is a fascinating one. Look closely at the center of this image and keep looking at it. Don't take your eyes off the center. Soon you will feel as though the pattern is moving, but of course, it is not. (you may have to click on this one for it to work)
3. In this optical illusion, you think you see a white triangle on top of the black triangle. In reality, there is no white triangle. The way the image is set up, with the slices out of the black circles, encourages the brain to "fill in" the missing elements of a triangle, and that is what you see!
Reverse Colors Illusion
4. For this example, you may want to click to enlarge the image. Then stare at the center of the colored hexagon below and count slowly to 20. Then look over at the black star and keep your eyes on the star. Your brain will reproduce the hexagon, but the colors will be reversed!
5. This one and the next are my two favorites. They're called afterimage illusions. Stare at the four vertical dots in the center of this image and count slowly to 20. Then close your eyes and keep them closed to allow the image to develop. What do you see?
6. Another one like it! Try to get the whole image within your view. Stare at the aqua colored blob in the center of the image. then count slowly to 20. Then close your eyes and wait a moment. Isn't that creepy?
How Creative Are You?
This series of optical illusions tests your brain's ability to see both images within the one presented. Presumably it will measure how quickly your brain works and how creative you are. Whatever the claims for this particular optical illusions test, it's fun to give it a try.
Was your brain fooled?
So, did we fool your brain? Kind of makes you wonder about the brain's power over us, if it is capable of altering our perceptions so easily. Optical illusions serve to remind us that we are not as much in control of our thoughts and perceptions as we think we are. It's as if your brain had a mind of its own!
Click HERE for more awesome optical illusions!
© 2011 Katharine L Sparrow
icountthetimes on November 23, 2011:
Wonderful optical illusions and I love that a detailed explanation is given for what actually causes them.
RGNestle from Seattle on November 07, 2011:
I don't like to look at Michael Jackson, but I'm fascinated by the clarity and detail in the last OI. That was quite amazing! Is there a specific name for this kind of OI? Thanks for the cool Hub!
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Glenn Stok from Long Island, NY on November 03, 2011:
It's amazing how the brain interprets things and provides its own perceptions. I especially got a kick out of number 7 when I closed my eyes. The face seems to glow in the darkness. Wow!
Welcome to HubPages and congratulations on the nomination for Hubnugget.
Joni Douglas on November 03, 2011:
Kathy from New Jersey , USA on November 03, 2011:
wow that is soo freaking cool :)
aquatic guru on November 03, 2011:
Wow! that is so weird and cool at the same time!!
Old Poolman on November 03, 2011:
Wow, this is fascinating. Great job and thanks for sharing.
Joyful Read from Boise, ID on November 03, 2011:
Love these! Thanks for sharing. Voted up!
Mary Wickison from Brazil on November 03, 2011:
I have never seen those particular ones. Optical illusion were always something I enjoyed but didn't understand how they worked. It is amazing when you think how complicated the brain is and how little we understand of it.
Interesting hub, congratulations on you hubnugget nomination. Voted up.
cardelean from Michigan on November 01, 2011:
I love optical illusions. It always fascinates me. Thanks for sharing these. Congrats on your nomination and welcome to Hubpages!
Deborah Reno from First Wyoming, then THE WORLD on October 31, 2011:
Congratulations on your hubnuggets nomination. Love these illusions. They are great.
Judy Specht from California on October 30, 2011:
Fun and interesting hub. The dot one that looked like was moving made me nauseous, but I loved it. Nice work.
Shawn Scarborough from The Lone Star State on October 29, 2011:
Interesting hub, I love optical illusions. Congrats on your Hubnugget nomination!
Michelle Simtoco from Cebu, Philippines on October 28, 2011:
I enjoyed this very much! Some are familiar but others are new to me. Thanks for sharing!
Congratulations on your Hubnuggets nomination! This way to read and vote Sparrowlet: https://enellelamb.hubpages.com/hubnuggets6/hub/Wh... Have fun!
Joanna McKenna from Central Oklahoma on October 02, 2011:
I don't know why or how they work, but I *love* optical illusions...as long as they're on paper. Once visited a "fun house" that all the way through *appeared* to be level but wasn't. Really messed with my sense of "reality" and left me slightly disoriented for several hours. ;D