Scotoma

That condition in which there is a blind or partially blind area in the visual field. Sometimesthe patient will complain of seeing dark, vanishing, cloudy spots before the eyes. Absolute S., apart of the visual field in which there is absoluteblindness.

Source: Ophthalmic Dictionary including pronunciation, derivation and definition of the words used in Optometry and Ophthalmology by James J. Lewis, Oph. D. Professor of Optometry in the Northern Illinois College of Ophthalmology and Otology, Chicago.