04-09-2006, 03:13 PM
Amaurosis fugax is a short-lived episode of blindness in one eye (monocular). This symptom usually develops suddenly, and many individuals describe the event as "it was as if a shade or curtain came over my eye." It is caused by a blockage or low blood flow within the main blood vessel supplying the eye. Blockages are usually due to a blood clot or plaque (small piece of cholesterol) that breaks off from a larger artery and travels upward to the brain or eye, becoming lodged in the main artery supplying the eye. Low blood flow to the eye may also result from a critical narrowing of one of the main blood vessels supplying blood to the brain and eye. The monocular blindness of amaurosis fugax is generally brief, but in rare cases it may be prolonged or permanent.