You are looking at a black and white picture of a vase when someone comes by and comments on the two girls in the picture. "What girls?" may be your first response, but then you examine the piece of art closely and there they are: two girls facing each other where when you first looked, there was only a vase. We are often told that seeing is believing, but that isn't always the case. When what is there is different from what we see, we call this an optical illusion. Optical illusions can happen when our brain can't understand what it sees. Our brain makes many assumptions about what we see, and optical illusions use patterns or colors to trick our brains.
Learn more about optics and optical illusions here.
What is an optical illusion? Is what you see what is really there? Learn more about optical illusions and test yourself with examples here.
Just because you see it doesn't mean it is (or isn't) there. Take a trip through the world of optical illusions.
Sometimes, what we see isn't what's actually there. Learn about illusions and how simple tricks can make your brain see, or not see, what's right in front of you.
Why do you see one thing while someone else sees another? Optical illusions work by fooling your brain.
Optical illusions have been around for a long time. See classic examples and learn how to make your own!
How do our eyes work? Explore how your eyes take in information and how a few simple changes can make them see what isn't really there.
In this PDF, the Museum of Vision explains how the eye works and includes several illusions.
Just how good are your eyes? Test yourself against these mind-bending illusions and see who wins.
A picture is worth a thousand words. How about a picture that is more than a picture? Explore how small changes in color and size affect what you see.
Get a glimpse of the magic behind some amazing optical illusions.
Dig deeper into the science behind common optical illusions.
Check out some neat optical illusions on this page from the Smithsonian.
Did you know there are certain shapes that can make you think they are moving, even when they are still?
Sometimes, seeing isn't believing. Explore a range of visual illusions that will leave you guessing.
This is a classic optical illusion: Do you see a chalice or two faces?
LiveScience explores the art of optical illusions and explains the science behind some of the best ones.
Want to get your hands dirty? This easy-to-follow guide shows you how to make amazing illusions that will stump your friends.
A great tutorial explains how our brains work and how little things can make your brain see what isn't there.
Get a more in-depth understanding of optics with these interesting videos and projects!
Ready to put yourself to the test? This page is full of interesting illusions that will stretch your brain.
On a hot day, it can look like there is water floating in the air. This is an illusions caused by heat and light. Learn more about mirages and how they are created.
Go behind the science of optical illusions and see how we can trick our brains to see what doesn't exist.
This interactive website contains many illusions.
Tie your brain in knots with this extensive gallery of visual illusions!
See if you can figure out these optical illusions before time runs out!
Can you find the black dot? Or is there one at all?
Follow the instructions to draw your own optical illusion.
This is an in-depth look at how our brains make images and how to fool them.
A scientist looks at tricks that fool the eyes.
Are your eyes are sharp as you think? Test your skills with these perception challenges!
Try your hand at this traditional optical illusion.
Colors don't actually talk, but this video shows how colors can be made to disappear from your sight.
Optical illusions aren't only pictures. This short video explains how the Parthenon, one of the most famous buildings in history, contains optical illusions.
This short article explains what happens when the eyes and the brain can't agree and how that creates optical illusions.
A simple video shows how your eyes can be fooled by three-dimensional objects. Watch until the end to discover the trick to this amazing illusion.
Learn more about optical illusions and how your brain can be tricked to see things that aren't really there.
Think your brain is up to the challenge? National Geographic's Brain Games will show you just how much your brain can be fooled. Watch episodes or explore the collection of optical illusions.
Check out some more fun optical illusions on this page.
Read a more scholarly look at just what goes on in our brains when what we see and what we think we see don't agree.