Voyeurism may be considered in two ways. The Canadian Oxford Dictionary defines a voyeur as "a person who derives sexual gratification from the covert observation of others as they undress or engage in sexual activity."
Voyeurism may also refer to a sexual disorder or paraphilia. Voyeurism paraphilia is characterized by :
Many individuals include voyeuristic fantasy or behaviour in a repertoire of sexual fantasies. It is only when these fantasies become a focus for an extended period of time (six months or more) and cause distress or impairment in one's life that this would be diagnosable as a paraphilia.[1]
The voyeurism paraphilia often accompanies other personality disorders such as exhibitionism.[2] According to some psychiatric studies, 20% of people involved in voyeurism will go on to commit more serious sexual assault offences.[3]
[1] The American Psychiatric Association's Diagnostic and Statistical Manual on Mental Disorders quoted in Meg S. Kaplan and Richard B. Krueger, "Voyeurism: Psychopathology and Theory" in Sexual Deviance: Theory, Assessment and Treatment (New York: The Guilford Press, 1997), pp. 297-310, at p. 297.
[2] Hanson, R. Karl and Andrew J.R. Harris, "Voyeurism: Assessment and Treatment," in Sexual Deviance: Theory, Assessment and Treatment (New York: The Guilford Press, 1997), pp. 311-331, at pages 313 and 314.
[3] Ibid.