Also known as unformed visual hallucination and unformed vision. All three terms are used to denote a visual hallucination depicting an amorphous shape or image. The term unformed hallucination derives from a classification of hallucinations that uses phenomenological form as a guiding principle. It is used in opposition to the term * formed hallucination. Although it is traditionally used with regard to the visual modality, the term unformed hallucination also applies to an auditory hallucination consisting of static noise (i.e. *tinnitus).
References
Ey, H. (1973). Traité des hallucinations. Tome 1. Paris: Masson et Cie., Éditeurs.
Dictionary of Hallucinations. J.D. Blom. 2010.