phantom vision

   The term phantom vision is indebted to the Greek noun phantasma, which means ghost or spectre. It was introduced in or shortly before 1969 by the American neurologist Robert Cohn (d. 2006) to denote an illusory or hallucinated visual sensation occurring after unilateral or bilateral eyeball enucleation. The seven individuals originally reported by Cohn had all suffered from traumatic enucleation due to explosives. The visual sensations they reported were described by him as follows: "In each case the individuals indicated that they had transient experience of visual sensations in the absent eye. Some disclosed the feeling that they were actually seeing normally with the ablated eye; but this was always accompanied by a subsequent feeling of 'strangeness or craziness'." Cohn's notion of phantom vision is analogous to that of the *phantom limb. The phenomena described by him include * unformed and * formed visual hallucinations, *photopsia, * Eigengrau (i.e. idioreti-nal light), and a condition reminiscent of the *Anton-Babinski syndrome (i.e. denial of blindness). However, Cohn's subjects differed from individuals with the Anton-Babinski syndrome in that they were not persistent in their belief that they could actually see with their enucleated eyes. As to the pathophysiology of phantom vision, Cohn postulated an association with peripheral rather than central irritative effects. The occurrence of visual percepts during periods of mental relaxation was interpreted by him as a sign "that the patients responded to normally subliminal stimuli." Conceptually and phenomeno-logically, phantom vision is related to *Charles Bonnet syndrome.

   References

   Cohn, R. (1971). Phantom vision. Archives of Neurology, 25, 468-471.