Optical illusions are images or pictures that are perceived differently than they are. Optical illusions occur when our eyes send information to the brain that tricks us into perceiving something that does not match reality.
Optical illusions can use color, light, and patterns to create images. These images can be deceptive or misleading to the brain. Creating a perception that in reality does not match the true image. When the brain and the eyes try to communicate in simple language, it gets a little mixed up. The eyes take in information very quickly, but the brain needs to rest, this is what causes the mix-up.
Some optical illusions are physiological. This means that they are caused by some sort of physical means in the eyes for the brain. Optical illusions involve visual deception. Due to the arrangement of images, the effective color, and the impact of a light source. Not everyone experiences visual illusions the same way.
There are four types of optical illusions:
- Ambiguities- Ambiguous illusions are those objects or pictures that considerably alter their appearance. More than one figure is there in ambiguous images and therefore it appears differently when looked at from different angles.
- Distortions- Distorting illusions are characterized by distortions of size, length, or curvature.
- Paradoxes- Paradox illusions are generated by objects that are paradoxical or impossible in “real life” or three dimensions but look oddly convincing and perplexing in two-dimensional drawings. Such illusions are often dependent on a cognitive misunderstanding that adjacent edges must join.
- Fictions- Fictions are when a figure is perceived even though it is not in the stimulus like the Kanizsa Triangle
Optical illusions date back to ancient Greece. The Greeks used optical illusions in their art and architecture. On temples roofs were built at a slant yet observers believed that the rooftops were curved.
Understanding optical illusions became a fascination of many philosophers:
- In 5 BC, Epicharmus said, “the mind sees and the mind hears, the rest is blind and deaf“.
- Protagoras believed the opposite, he believed optical illusions were dependent on the environment. Tricking us, not the senses.
- In 350 BC Aristotle decided both Epicharmus and Protagoras to be correct. Aristotle also believed our senses aren’t that difficult to trick.
- Plato, deciphering the trickery and ultimately the reality behind illusions is possible with the use of mind and senses.
From ancient Greek philosophers to modern-day psychologists, scientists, researchers, and artists continue to be amazed by this phenomenon we call optical illusions. Optical allusions can be fun and fascinating, but they can also tell us a great deal about the brain and perceptual system functions.