Entoptic
"The entoptic phenomena in darkness favoured the occurrence of hallucinations."
- Collected Papers on Analytical Psychology by C. G. Jung
entoptic /ɛnˈtɒptɪk/
adjective (of visual sensation) resulting from structures within the eye itself
Etymology: ento- + optic
ento: word-forming element used chiefly in biology and meaning "within, inside, inner," from Greek ento-
optic: from Middle French optique, obtique (c. 1300) and directly from Medieval Latin opticus "of sight or seeing," from Greek optikos "of or having to do with sight," from optos "seen, visible," related to ops "eye,".