Playing tricks on our brains
The pictures you can see here contain hidden images. Can you make out what they are? Have a good look before you read on. The answer is at the bottom of the webpage.
Drawings like this one make our eyes play tricks on us. They fascinate us because we realize our eyes aren't really seeing the world exactly as it is. Naturally, we want to know what is going on. Understanding the kinds of mistakes our eyes make can help explain how our brains process images.
Seeing is a complex process
We don't just capture images like a photograph or a video, our brains also understand what parts of these images mean. For many years now, computer scientists have been trying to teach computers to see like we do — to pick the important things out of a picture. They have had a lot of trouble doing this because our vision is so complicated.
The brain has all kinds of ways of making images simpler, so that it can find the important things in an image and get rid of all the unimportant details. Visual illusions can help us to work out the ways in which the brain has made things simpler. When the brain simplifies something, it can make mistakes. Visual illusions are examples of where the brain has made mistakes. By looking at the kinds of mistakes the brain makes, we can work out how the brain does the things it needs to do to make sense of the images it receives.
If scientists can work out how we see, all kinds of incredible things might be possible. Doctors would be more able to help people who have trouble with their vision. Computer scientists could teach computers to see like us. If computers could see, they might be able to drive our cars for us, recognise intruders in a building for us and maybe serve us in a restaurant.
There is still a long way to go before we fully understand how people see. By experimenting with these Incredible Illusions, you can discover some of the things we already know about vision.
Answers: some people say that the first (green and white) image is of Jesus Christ, and the second one (purple and white) is of Adolf Hitler.