The term obscuration comes from the Latin adjective obscurus, which means dark. It translates as 'darkening'. The term is used to denote a transient loss of visual perception. Such losses of visual perception typically last no longer than a few seconds. Pathophysiologically, obscuration is associated with compression of the optic nerve head perfusion, which is in turn attributed to raised intracranial pressure, as in sneezing, coughing, and straining. Etiologically, obscuration is associated primarily with papilledema and optic disc drusen. Conceptually as well as phenomenologically, obscuration should not be confused with *scieropia, *scierneuropsia, and * achromatopsia.
References
Kosmorsky, G.S., Rosenfeld, S.I., Burde, R.M. (1985). Transient monocular obscuration-? amaurosis fugax: A case report. British Journal ofOphthalmology, 69, 688-690.
Dictionary of Hallucinations. J.D. Blom. 2010.