External hallucination

Deliriants by Anonymous DEL user - This image represents the sinister external hallucinations commonly induced by deliriants.

An external hallucination is defined as the perception of a visual hallucination which displays itself seamlessly into the external environment as if it were actually happening.^[1][2] This is in stark contrast to internal hallucinations, such as dreams, that occur exclusively within an imagined environment and can typically only be viewed with closed eyes.

This effect is capable of manifesting itself across the 4 different levels of intensity described below:

1. Fleeting hallucinations - At the lowest level, external hallucinations generally consist of movement within the peripheral vision and ill-defined, fleeting hallucinations which disappear once a person double takes.
2. Vaguely defined hallucinations - At this level, the hallucinations are visible within one's direct line of sight, but are not fully defined in their appearance. This means that, although visible, they do not look completely detailed and are often extremely blurry or semi-translucent with little, if any, colour.^[2]
3. Partially defined hallucinations - At this level, the hallucinations become distinct enough in their detail and vividness to extend beyond transparent, colourless, or blurry manifestations. However, they still remain unconvincing and do not quite live up to the detail of everyday life.
4. Fully defined hallucinations - At this level, the hallucinations have become completely realistic and will rarely disappear simply because a person double takes. They are now capable of a completely convincing and photorealistic appearance and their behaviour becomes far more lifelike. Additionally, they may become numerous enough to fully engulf the entirety of the person's environment.^[2]

Alongside a specific levelling system, there are also certain environmental factors that directly alter both the likelihood of external hallucinations manifesting themselves and the level of detail of which they are rendered with. For example, the more unfamiliar with the external environment a person is, the more likely it is that this effect will manifest itself. Cluttered areas tend to produce more external hallucinations and the amount of light within a room is inversely proportional to the intensity of them, with less light leading to significantly more hallucinations and more light leading to fewer, although more detailed, hallucinations.

The content within these external hallucinations can be further broken down into four distinct subcomponents. These are described and documented within their own dedicated articles, each of which are listed below:

• Autonomous entities
• Object activation
• Perspective hallucination
• Scenarios and plots
• Settings, sceneries, and landscapes
• Shadow people

It is worth noting that the content, style, and general behaviour of an external hallucination is often largely dependent on the emotional state of the person experiencing it. For example, a person who is emotionally stable and generally happy will usually be more prone to experiencing neutral, interesting, or positive hallucinations. In contrast, however, a person who is emotionally unstable and generally unhappy will usually be more prone to experiencing sinister, fear-inducing, and negative hallucinations.

External hallucinations are often accompanied by other coinciding effects such as delirium, internal hallucinations and delusions. They are most commonly induced under the influence of heavy dosages of deliriant compounds, such as DPH, datura, and benzydamine. However, they can also occur less commonly under the influence of psychedelics, dissociatives, stimulant psychosis, and sleep deprivation.