ENTOPTIC PHENOMENA

Entoptics (from the Greek, meaning “within vision”), also known as phosphenes, are complex and diverse luminous geometric images derived from the human central nervous system, produced specifically within the optic cortex and characteristic of certainaltered states of consciousness, including shamanistictrances. Links between entoptics, altered consciousness, and shamanisms have been explored in a number of visual culture studies. Entoptics have been vociferously debated inrock artresearch in particular, due to their use in aneuropsychological modelproposed by theSouthern Africanrock art researchersDavid LewisWilliamsandThomas Dowsonin order to establish the origins of some rock art imagery in altered-consciousness and related shamanistic practices.