What is an Optical Illusion?

While many people equate optical illusions with mirages, the fact is that the phenomenon is much broader in scope. Essentially, an optical illusion is any instance where the information gathered by the human eye is translated in the brain in such a manner that a visual illusion of some type results. An optical illusion may be utilized in a number of different applications, such as games, psychological evaluation and therapy, and the creation of art.

One of the generally accepted understandings about the visual phenomena of the optical illusion is that the brain will attempt to process visual data by relating it to the worldview of the individual. That is, the collected life experience of the individual will influence how the brain interprets the visual input that is received. An example of this understanding has to do with inkblots that are sometimes used in counseling and therapy. When asking the patient to identify the shapes that he or she sees in the ink blots, the brain calls upon past experience and knowledge to define the visual information received as some object that is familiar and therefore recognizable.

Visual illusions are also often included in games that are widely distributed. Many people have been invited to stare at what appears to be a jumble of colors or random arrangement of dots on a contrasting color background, then either look away or blink the eyes. Often, an image will appear before the eyes. As with the inkblots, the result of this activity is an optical illusion that is created by drawing on the life experience of the individual.

Even art can be the subject of a limited type of optical illusion. Depending on the background of the viewer, a painting or piece of sculpture may appear to take on elements that are not readily identified by other people. However, it is not unusual for the element to be recognized by others once the detail is pointed out and thus assimilated into the life experience stored in the brain.

An optical illusion may not have any real existence in the form of an object that can be touched. The mirage is an excellent example of this type of illusion. The combination of the desires of the individual along with any formation that the brain can interpret as being a physical manifestation of that desire will lead to the visual illusion. However, the mirage generally disappears from the field of vision when the individual attempts to physically engage the perceived image.