The term kalopsia comes from the Greek words kalos (beautiful) and opsis (seeing). It is used to denote the aesthetic overrating of sensory, illusory, and hallucinatory phenomena, in the sense that these are perceived as beautiful, friendly, and/or comforting. As indicated by the German-American biological psychologist and philosopher Heinrich Klüver (1897-1979), the * geometric hallucinations occurring in the context of mescaline intoxication tend to be quite indiscriminately described as beautiful. It is this kind of indiscriminate positive valuation which is covered by the term kalopsia. The term is used in opposition to * kakopsia (i.e. seeing things as ugly, sinister and/or menacing).
References
Critchley, M. (1939). Visual and auditory hallucinations. British Medical Journal, 2, 634-639.
Critchley, M. (1949). Metamorphopsia of central origin. Transactions ofthe Ophthalmologic Society of the UK, 69, 111-121.
Klüver, H. (1966). Mescal and Mechanisms of hallucinations. Chicago, IL: University of Chicago Press.
Dictionary of Hallucinations. J.D. Blom. 2010.