It is an entoptic phenomenon, meaning that its source lies within the eye or visual system itself.
Perception of phosphenes should not be confused with visual hallucinations, "flashbacks," and hallucinogen persisting perception disorder while entoptic phenomena can be part of them.
Investigation of the source of the blue field entoptic
Dowson 1988 "The Signs of All Times Entoptic
Phenomena," Current Anthropology 29 (3):201-245.
Pearson might have mentioned the problems presented for his thesis by the Australian case, where entoptic imagery abounds in rock-art, but trance and ASC-related shamanism is rarely observed in the ethnographic record.
Dowson, "The Signs of All Times: Entoptic Phenomena and Upper Paleolithic Art," Current Anthropology 29 (1988):201-45.
eidetic imagery, entoptic
phenomena, hallucination, synesthesia), psi experiences (e.
Additionally, some authorities have included the presence of more basic hallucinations, such as spots, flashes of light and patterns, which are not attributable to entoptic
The healthy individual may sometimes notice physiological entoptic
phenomena, particularly peripheral flashes when viewing in very low illumination.
The two entoptic
phenomena strongly associated with the macular pigment are Haidinger's brushes and Maxwell's spot, both of which are only seen under highly specific experimental conditions.
They can be particularly troublesome to elderly people, especially where the pupils are small, because the entoptic
image, which may be moving, is superimposed on the real image.
Rock art or Rorschach: Is there more to entoptics
than meets the eye?