Editing Hallucination (section)

===Visual===
{{main|Visual hallucination}}
{{see also|Pareidolia|Palinopsia}}

A ''visual hallucination'' is "the perception of an external visual stimulus where none exists".<ref>{{cite web| vauthors = Pelak V |title=Approach to the patient with visual hallucinations|url=http://www.uptodate.com/contents/approach-to-the-patient-with-visual-hallucinations|website=www.uptodate.com|access-date=2014-08-25|url-status=live|archive-url=https://web.archive.org/web/20140826120056/http://www.uptodate.com/contents/approach-to-the-patient-with-visual-hallucinations|archive-date=2014-08-26}}</ref> A separate but related phenomenon is a ''visual illusion'', which is a distortion of a real external stimulus. Visual hallucinations are classified as simple or complex:
* ''Simple visual hallucinations'' (SVH) are also referred to as non-formed visual hallucinations and elementary visual hallucinations. These terms refer to lights, colors, geometric shapes, and indiscrete objects. These can be further subdivided into [[phosphene]]s which are SVH without structure, and [[photopsia]]s which are SVH with geometric structures.
* ''Complex visual hallucinations'' (CVH) are also referred to as formed visual hallucinations. CVHs are clear, lifelike images or scenes such as people, animals, objects, places, etc.

For example, one may report hallucinating a giraffe. A simple visual hallucination is an amorphous figure that may have a similar shape or color to a giraffe (''looks like'' a giraffe), while a complex visual hallucination is a discrete, lifelike image that ''is'', unmistakably, a giraffe.