Difference Between Illusion and Hallucinations

Difference Between Illusion and Hallucinations | Illusion is a wrong perception or perception in a wrong way of the real object. On the other hand, hallucination
is a wrong perception in the absence of any object. Both illusions and hallucinations are perceptual disturbances.

So, in the case of hallucinationno object is present, but the person who perceives there is some object, but in case illusionthe person perceives an object differently than it actually is.

when there is hallucination, a person is seen in complete darkness or hears some sounds when there is no sound at all. However, in illusionthere are some external stimuli that must be seen or heard, but the impression received by the person concerned is misinterpreted.

This post will help you understand the basic difference between illusion and hallucination.

Definition of Illusion

When a person misperceives an object in a way that is not the same as the quality of the actual object, it is called an illusion. Therefore, in illusion, we mistakenly perceive one object for another. Illusions can also be referred to as misperceptions.

Thus, the misperceptions arising from the misinterpretation of the information gathered by the sense organs are considered as illusions. Furthermore, the false perception of real external stimuli generally occurs when the basic level of sensory stimulation i.e. consciousness is low.

One should not confuse between illusion and dream, and also between illusion and imagination, because in case of illusion, perceived stimuli are present but in case of dream, no object is present in reality. On the other hand, in the case of imagination, the perceived object is the creation of the person’s mind, which is not an illusion.

Illusion Type

Illusion of Size: In this type of illusion, the person has a wrong perception of the size of the object. It basically depends on how far or near the object is.
Long Illusion: This is also known as the Muller-Lyer Illusion. In this case, the two lines are similar but still, the bottom line is considered by the person to be longer. Furthermore, it is caused as a result of our interpretation of the angle at the end of the line.
Illusion of Perspective: Another name for this illusion is the Ponzo illusion. In this case, even when two parts or objects are identical in shape and size, one appears larger than the other, which is the result of misleading perspective clues. This happens when we rush to add a third dimension to the stimulus, namely depth. And the reason behind the appearance of one larger form is that it appears far away.
Illusion of Curvature: In this illusion, even when the two horizontal lines are straight and parallel to each other, they appear curved. Furthermore, it may be difficult to see them as they really are, i.e. straight and parallel to each other, due to our eye movements and possible exaggeration of acute angles.
Horizontal or Vertical Illusions: Even when the horizontal and vertical lines are the same length, the vertical lines are considered longer. This is the result of our field of vision being generally a horizontal ellipse. In vertical line perception, upright eye movements produce more muscle tension than horizontal movement, in horizontal line perception.
Illusions of Movement: When we see an object moving when we see it, which is not at all moving, such an illusion is called the illusion of movement.

Cause of Illusion

There are several causes of illusions, these are:
Confusion
Eye Movement
Tendency to Wholeness
Perspective
Prejudice
Emotion
habit
Stimulus Contrast
Sense Organ Defect
Imperfect Insulation

Definition of Hallucinations

When a person experiences a false sensory perception, in the absence of an actual external stimulus or object, it is called a hallucination. It should be noted that hallucinations are usually experienced in the real outside world, and not in the mind of the person concerned.

In this way, hallucinations differ from imagination. It’s an experience that seems to happen without an outside source. It is an alleged perception of something, which does not really exist.

Hallucination Criteria

To be labeled a hallucination, it must meet the following criteria:

Perception must take place in the absence of a stimulus (object).
It must be as clear (real) as the real perception.
It has to happen in an external and objective space.
It must be under the willful control of a person.

Types of Hallucinations

There are five types of hallucinations, namely:

Auditory Hallucinations: This happens when a person hears some voice or sound, telling him to do something.
Visual Hallucinations: Occurs when someone says that he can see someone or talk to someone, who is not there.
Olfactory Hallucinations: A form of hallucination in which a person smells a smell that is not there.
Gustatory Hallucinations: Symbolized by the tongue, identified with a taste that is not related to the food consumed. This can result in a refusal to eat.
Tactile Hallucinations: Tactile hallucinations are when a person complains of insects crawling on their body when in fact there is nothing.

After we have discussed the meaning and types of the two, now we will discuss the difference between illusion and hallucination: