Also known as ocular spectra. The two terms were introduced as synonyms in 1847 by the British surgeon Walter Cooper Dendy (17941871), denoting a subclass of'ghosts of the mind's eye', which itself constitutes a subclass of what Dendy calls "phantoms or ghosts. The notion of illusive perception can be seen as an equivalent of the later notion of "personification (i.e. a " compound hallucination depicting a human being). Dendy uses the term illusive perception in opposition to the term "illusive conception.
References
Dendy, W.C. (1847). The philosophy of mystery. New York, NY: Harper & Brothers.
Dictionary of Hallucinations. J.D. Blom. 2010.