Brightness alteration

Brightness alteration is a distortion or change in the intensity of perceived brightness comprising a person's vision. This usually results in the person's vision becoming dimmer or darker, [1] [2] [3] but could also potentially result in it becoming lighter and more vivid [2] [4] depending on the person's environment and substances they have consumed.

Brightness alteration can be accompanied by the coinciding effects of pupil dilation or constriction and photophobia. It is most commonly induced under the influence of moderate dosages of hallucinogenic compounds, such as psychedelics, dissociatives, and deliriants.


  1. Kleinman, J. E., Gillin, J. C., & Wyatt, R. J. (1977). A comparison of the phenomenology of hallucinogens and schizophrenia from some autobiographical accounts. Schizophrenia Bulletin, 3(4), 562. |
  2. [1][2]
    Fischer, R., Hill, R. M., & Warshay, D. (1969). Effects of the psychodysleptic drug psilocybin on visual perception. Changes in brightness preference. Experientia, 25(2), 166-169. |
  3. Abraham, H. D., & Wolf, E. (1988). Visual function in past users of LSD: Psychophysical findings. Journal of Abnormal Psychology, 97(4), 443. |
  4. Baggott, M. J., Coyle, J. R., Erowid, E., Erowid, F., & Robertson, L. C. (2011). Abnormal visual experiences in individuals with histories of hallucinogen use: a Web-based questionnaire. Drug & Alcohol Dependence, 114(1), 63-64. |




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