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Can Optical Illusions Be Harmful?

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Mackenzie Taylor

on 14 April 2014

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Transcript of Can Optical Illusions Be Harmful?

What Are Optical Illusions Used For?
Optical illusions are mainly used for entertainment, advertising, eye doctor tests, science (figuring out how the brain/eyes work).
What Causes Us To Have Optical Illusions?
Sight takes place in the brain. When you look at something, you see it upside down. The brain puts together nerve impulses from the optic nerve and flips images right side up so we can see. Certain parts of the brain can be damaged, causing sight problems.
How Do Optical Illusions Work?
Optical Illusion Surveys
We asked our class what word they saw first in the picture below. Almost everyone saw the word "good" first, but everyone eventually saw the word "evil". It took people different periods of time to find the word evil. Some people needed help to find the word, while others found it almost instantly after they saw good.
One person said once they saw evil, they saw it everytime they looked at the picture. Two people did, however see evil first. They said they looked towards evil first because it was bright.
Optical illusions were first used by the Greeks. They built their temples so the roofs were slanted, giving the illusion that the temple was actually standing straight. They also made the columns bulge so from a distance they would look perfectly proportioned.
Can Optical Illusions Be Harmful?
We asked our class which animal they saw first; the cat or the mouse. 17 people saw the cat first, 4 people saw the mouse first, and 3 people saw both.
People who saw the cat first said they saw it because it was larger, while people who saw the mouse first said they saw it because it was more visible and stood out (being white in the centre of a black cat).
People who saw both first looked at it as a whole picture and may not have noticed that it was an optical illusion and instead just saw the two animals.
The first optical illusion is believed to have been invented by Oscar Wilde. It was based on a picture that was painted using only the colour grey. During observation, the picture appeared full of colour, which was an affect of the optical illusion. The painting was later used to test and diagnose mental conditions such as dyslexia and insanity.
By: Mackenzie and Madison
Optical illusions use colour, light and patterns that can be misleading to the brain. They simply trick our brains into seeing things that might or might not be real or accurate. It's not your eyes that cause optical illusions but it is the way that your brain/visual system interprets images.
Scientists don't like calling them "optical illusions" because the true definition of an optical illusion is when an illusion happens because of some parts of the eye. For example, floaters. Floaters are small specks, spots or shadowy shapes that seem to float in your vision. They are caused by tiny flaws in the fluid that fills the eye. They are real. True optical illusions are rare, so scientists prefer to call them visual illusions.
We all have an area of the eye called the "blind spot." We don't usually know we have a blind spot because eyes move around enough to see. Sometimes this blind spot can cause the brain to put together the impulses incorrectly, causing us to see differently. The eyes and brain work together to help us see and they also work together to see illusions.
History of Optical Illusions
Epicharmus, Protagrus, and Aristotle were some of the first to think of different theories and ways to explain optical illusions.
Epicharmus believed that our senses were not paying enough attention and caused illusions.
Protagrus thought our senses were fine, but believed that it was our environment that caused illusions.
Aristotle thought that Epicharmus and Protagrus were both right and wrong. He believed that our senses could not be trusted, but they could easily be fooled.
Another Greek was Plato. He said that our eyes need our minds to help understand what they see. This is exactly what we believe now.
How Are Optical Illusions Harmful?
Most optical illusions are not harmful. They are proven to not harm your vision. However, if you stare at one for too long, it may cause eye strain, sore/tired/itchy eyes, dry or watery eyes, headaches, blurred or double vision, sore neck/back, shoulder pain, light sensitivity, or difficulty focusing.
Some optical illusions can be dangerous. They may cause dizziness, headaches, vomiting, and epileptic symptoms. After looking at an optical illusion, never close your eyes, or it will make the symptoms worse.
Our Opinions
Based on our research, we know that optical illusions have some negative effects, but we don't think it's something we have to be really worried about. In the future, we think companies could use subliminal messages in advertisements to persuade people into doing things or buying things that could harm them. Subliminal messages are when you think you are seeing one thing, but you are actually seeing something else. For example, you might think you see a commercial with a dolphin jumping, but you are actually seeing a company logo, which causes cravings to want to buy that product. We think this could be used in the future to persuade people into buying or using dangerous products.
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