How an Eye Exam Can Save your Life. Hollenhorst plaques are white, Cholesterol plaques found in retinal (eye) blood vessels. They often cause a phenomenon, Amaurosis Fugax, which is a transient monocular loss of vision lasting from seconds to minutes. Many describe it as a curtain coming across their vision. The presence of Hollenhorst plaques can increase the risk of Strokes and Carotid... READ MORE