What is "scintillating scotoma"

n. a localized area of diminished vision edged by shimmering colored lights; in many people it indicates the onset of migraine [syn: flittering scotoma]

Scintillating scotoma, also called visual migraine, is the most common visual aura preceding migraine and was first described by 19th-century physician Hubert Airy (1838–1903). It either precedes a migraine headache or can occur acephalgically (without headache). It is often confused with ocular migraine, which originates in the eyeball or socket.