An optical illusion appears when there is a distortion of reality that is perceived through sight.
The term illusion has its origins in the Latin illusĭo . It is a concept or an image that arises through the imagination or through a deception of the senses , but that has no true reality.
Linked to the senses, an illusion is a distortion of perception . We can talk about optical illusions (the most common), olfactory illusions, auditory illusions, gustatory illusions or tactile illusions.
Optical illusion
The optical illusion leads to perceiving reality in a distorted way through sight. This distortion can be caused by physiological issues (through excessive stimulation of the eyes or brain) or cognitive issues (depending on the way we perceive the world).
Among the most significant and famous optical illusions we would have to highlight, for example, mirages . These occur as a consequence of the perception of objects that we see far away and that, when reflected on a smooth surface, give rise to a liquid surface that does not actually exist. The clearest example of mirage is the one that takes place in deserts where the circumstances to which the individual is subjected and the characteristics of the place cause the individual to see things that do not actually exist.
The hologram is another important type of optical illusion. We can say that this is the result of a photographic technique that allows the development of three-dimensional images. However, we cannot forget other illusions of this type such as irradiation , the grid illusion or the stereogram .
An illusionist uses different resources to generate the illusion that something impossible from a logical perspective is happening.
Mentalism and magic
Mental illusion, also called mentalism, is, for its part, that science or art that makes the person who develops it use suggestion , mental agility or stage magic to be able to undertake mental control, psychokinesis, clairvoyance or precognition. We can also establish that this is a branch within what is known as illusionism .
Illusionism (or magic , in colloquial language) is known as the performing art that consists of using various means to create the illusion that something impossible is happening from a logical point of view: «Last night I saw an illusionist on television who cut a half to a girl .
There are many characters who throughout history have become a reference within illusionism. However, among all of them, the Frenchman Jean Eugène Robert-Houdin , who has been described as the father of modern magic, acquires special relevance. Among the tricks that he performed throughout his career and that later became widespread, the one in which a person from the audience shot him and he not only was not injured but appeared with the bullet between his teeth stands out.
The illusion according to psychology
For psychology , illusion is a hope that has no foundations . In a symbolic sense, it can be said that an illusion is a mirage (something that seems real but is not): "I had the illusion of solving things with her but I realized that it is impossible," "I thought I could win the race." , although it was just an illusion .
It should be noted that the positive meaning of hope ( "My greatest hope is to travel to Europe to meet my grandfather again" ) only exists in the Spanish language. In other languages , the term is always related to that which lacks support.