Optical Illusions: The Trick of the Eye

Optical illusions are defined as being perceived images that are different from reality. This is caused by the eye obtaining information that is processed by the brain that gives a perception that does not match the physical measurement of the physical source. All in all, there are three different types of optical illusions: literal optical illusions, physiological illusions, and cognitive illusions.

Literal optical illusions deal with the creation of images that are different from the things that make them. For example, in a picture, you might see three birds that are flying, but the three birds that are flying might form a smile or a triangular shape. Hence, what you see is valid, but there is also another image that has been created along with the physical image that you see. Sometimes, these type of illusions are easily recognized because they are well known and easy to find. An example of a literal optical illusion is below which is of a man and upside down it appears to be a princess:

Physiological optical illusions are effects on the eyes and the brain due to excessive stimulation from lights, color, size, tilt, movement,etc. An example of this is when you see a grid illusion where the lines are horizontal and vertical lines are white and the squares are black.This effect helps to produce black dots at all of the intersections of the white lines. Another example could be if you see two different patterns of colors, where one pattern seems to be moving even though it is not. An example of a physiological optical illusion is below of yellow and blue alternating colors that are crescent shaped heading in alternating directions in a circle causing your mind to think that the circles that you see are moving.

Cognitive illusions are defined as being unconscious inferences. These illusions can be divided up into distorting illusions, fiction illusions, paradox illusions, etc. Distorting illusions are images that deal with distortions of size, length, and position. Fiction illusions are images that we perceive, even though it is not the stimulus. Paradox illusions are images that are impossible such as never ending or continuous stairs. An example of a cognitive illusion is below, which shows staircases that seem to be coming from all directions that you can go up and down.

An opinion of mine on why we are fascinated with optical illusions is because we boggle at things that we don't understand. Our natural reactions to such phenomenon varies depending on how we receive the information and how we interpret it ourselves. Thus, meaning that some people might see optical illusions as being cool and strange, while others might see optical illusions as being weird and not normal. Everyone seems to have their own interpretation of optical illusions based on their own feelings and perception. Therefore, the majority of us would classify optical illusions as being along the lines of something that we can't explain as to why the eyes perceives the information the way that it does.

If you stare at the black cross above, you will slowly notice that all of the purple circles will disappear.

Do you seen an elderly couple gazing into each others eyes, two people sitting down while one plays the guitar, or both ?

Do you see a partially bitten apple, Steve Jobs side portrait, or both ?

Do you see a skull, a woman holding a basket over her head, or both ?

References

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