Understanding Perception: Optical Illusions and Your Eye

Your brain and your eyes work together to see and know the world around you. For example, your eyes see your friend's face, but it's your brain that remembers who they are. It's easy to think that you see things exactly as they are, but it's just as easy for your eyes and brain to be tricked by what they see. The direction you look at something, the way part of a picture is drawn, and even the colors you see can all change the way something looks to you. They can also change the way an object looks to someone else. For instance, you might see a different color than your friend does, even if you're looking at the same object. Optical illusions and eye tricks are pictures, sculptures, and sometimes even words that are made to try to trick your brain into seeing something. Testing your eyes with optical illusions can be a lot of fun.

• Optical Illusions and Tricks of Perception

  This short article is full of optical illusions to test out on your eyes. After each image, there's an explanation about what you're meant to see and what is actually there.

• Same Color Squares Illusion

  This illusion asks you to look at the squares in the image labeled A and B. Compare the two squares to see if your eyes can spot the trick.

• Color Perception

  On this page, you will click through three different images. All of them focus on how different colors surrounding the same color can trick your brain!

• Neuroscience for Kids: The Blind Spot

  This article can help you find your blind spots, which are parts of your eye that can't actually see. If something is in your blind spot, you won't be able to see it.

• Hole in Your Hand: Perception and Vision Science Activity

  This trick requires a couple supplies before you get started. After you have them, you'll learn how to see through a hole in your hand and why it works.

• Optical Illusions

  This article has different images to show you tricks that your brain can play with your eyes, from filling in things that aren't there to changing how you see colors.

• National Eye Institute: Optical Illusions

  This page asks you to compare the sizes of images on the screen. You have to figure out if your brain is being tricked.

• Butterfly Optical Illusion

  This activity helps you learn about how caterpillars change into butterflies and shows you how to make an optical illusion of your own.

• Wavy or Zigzag Lines?

  This image tricks your eyes into thinking some of the lines are zigzags and some are curvy.

• Elephant Legs

  This site explains what optical illusions are and gives you a list of different ones to look through.

• Arrows Optical Illusion Activity

  This activity teaches you how to make your own optical illusion to test out whether or not your eye can spot the trick.

• Albert Einstein or Marilyn Monroe?

  Depending on how close you stand to the screen, you might see a picture of Albert Einstein or Marilyn Monroe.

• Optical Illusions: Rainbows

  This article teaches you all about an optical illusion you see in nature: the rainbow!

• Nine Optical Illusions to Confuse Your Brain

  See if you can trick your brain into seeing people the same size or seeing a shrinking gray haze.

• Eye Openers: Exploring Optical Illusions

  Learn all about how your eyes work and how optical illusions can trick them. You'll also find plenty of examples for you to try out here.

• Optical Illusions on Scratch

  Use the space bar to move through different optical illusions to trick your mind.

• Optical Illusion Image Gallery

  This selection of images shows that details in an image can affect how we perceive what's really there.

• The Spinning Dancer

  Watch the dancer turn. When you first see her, she'll be spinning one way, but if you watch closely, you might just get her to change direction!

• M.C. Escher Cube Optical Illusion Video

  At first, the cube looks normal, but once it starts turning, you realize that your eyes have been tricked.

• Young Woman or Old Woman

  You might look at this picture and see a young woman first, or you might see an old woman, but they're both there!

• The Hidden Tiger

  In this picture, you see a tiger standing at the front of the picture. But can you find the hidden tiger that's in the picture, too?

• 25 Mind-Twisting Optical Illusion Paintings by Rob Gonsalves

  These paintings trick you into seeing one thing at first and then another. The shifting images show how easily your eye can be tricked.

• Make Your Own Optical Illusions

  This guide shows you how to make some of the most popular optical illusions at home.

• Sky and Water Eye Trick

  This painting by M.C. Escher tricks your eyes into seeing birds turn into fish.

• Warped Words and the Stroop Effect

  Try out this test to see if you can name the colors of words rather than saying the words themselves. It's really tricky!

• Optical Illusion

  This activity shows how your brain can be tricked into seeing two images on a page when there's only one.

• Seeing Things That Are Not There: Illusions Reveal How Our Brain Constructs What We See

  This article explains how our eyes can see one thing but our brain can flip it to see something else.

• Strength Optical Illusion Magic Trick

  Create a "strength tester" and fool your friends with this illusion.

• Kindergarten Optical Illusions: Eyes Play Tricks

  Print out the picture of the the flower and the bee. Once you have that, move the middle toward your nose to see the bee fly to the flower!

• Optical Illusions and How They Work

  Test your ability to solve the optical illusions while learning about how they work in your mind.

• Visual Curiosities and Mathematical Paradoxes

  This article teaches you about optical illusions and how impossible figures can trick your eyes.

• "Missing Corner" Cube Illusion

  As the cube turns, it tricks your mind into thinking the cube has a missing corner, or maybe you'll see a smaller cube in the front.

• The Reversing Arrow Activity

  This experiment shows how our eyes can be tricked with water. The challenge is to see if you can get the arrow to change direction.

• Science Meets Crafts Program Kit: Rainbow Illusion Yo-Yos

  This activity guide shows you how to create a yo-yo that has a rainbow on the side when you spin it.

• Sense Experiment: The Red, White, and Blue

  Stare at the picture, then look at a white piece of paper. What colors do you see?

• Perception and the Brain Lesson Plan

  Your eyes can be fooled in many ways. Check out this illusion, in which the dots appear pink at first but seem to change as you keep looking.

• Optical Illusion Sculptures in Action Video

  This video shows balls that appear to be climbing up the statues at first glance.

• Fish in the Tank Illusion Activity

  This activity guide has instructions to show you how to make your own fish in the tank illusion.