What are some optical illusions that you know of?

What is the relationship between optical illusions and physics I want to know how physics is involved when looking at an optical illusion.?

• Answer:

  There are multiple types of optical illusions. There are those that are real and the effect actually exists because of various physical phenominon, mostly assosiated with optics, and there are the type that cause our senses to be fooled. I will address the latter. What creates an optical illusion is different depending on the set up. Some are created by the eye itself and others are created by the brain's interpretation of the eye's messages. Some examples. A negative after-image. This is what you see when you stare at a certain picture for a very long time. The rods and cones in your retena become tired after the same messages are repeatedly fired. The "after immage occurs when you then look at something else. The cones and rods of the retena continue to fire but the tired reciever's signal is not as powerful. This means that you do not pick up certain colors. This lack of some colors causes the negative after image. Another illusion is the common "spinning wheel" illusion. Where a circle is created by sucessive radial lines. The eye is always moving in very small ammounts, even when you try to keep it still. When you move the eye tries to keep track of the lines using many small jumps. These jumps trigger the brain to experience the strobeoscopic effect which causes it to believe there is motion when there is not. Yet another type of popular illusion is created by creating a false perspective. These are commonly known as "Magic Eye" illusions. When the picture is held out of focus at the correct depth, the two different pictures that each eye sees overlap. This is the same thing that our eyes do to see immages in 3-D. The brain takes the two perspectives and adds them together. In this case it is fooled. The pictures overlap and the brain adds them together to create a 3-D immage. These are just a few explanations why optical illusions work as they do. Each and every type of illusion utilyses a different effect created by they eyes and brain.