Aura (symptom)
Negative scotoma: an area of partial or total blindness.  Usually it is followed by a scintillating scotoma, but the negative scotoma may be surrounded by a scintillating scotoma. A negative scotoma may be either be an absolute scotoma and may seem like a blank spot where the person can not see any light, or a relative scotoma in which some light may be seen but less than normal, the scotoma  may be blurry as if looking through thick plastic. Negative scotomas are usually not noticed by a person and are found by an eye or ophthalmic examination.