Spurious sanguineous lacrimation.

Sanguineous lacrimation is an unusual clinical entity that may be caused by a wide spectrum of abnormalities. Disorders of the conjunctiva or of the blood clotting mechanism are the most common underlying problems. This paper describes a bizarre case in which a 16-year-old girl used food colouring to simulate blood in the tears. The appropriate steps in the investigation of a patient's complaint of bloody tears are reviewed.