The setting-sun phenomenon is an ophthalmologic sign in young children resulting from upward-gaze paresis. In this condition, the eyes appear driven downward, the sclera may be seen between the upper eyelid and the iris, and part of the lower pupil may be covered by the lower eyelid. Pathogenesis of this sign is not well understood, but it seems to be related to aqueductal distention with compression of periaqueductal structures secondary to increased intracranial pressure.> However, it can also be transiently elicited in healthy infants up to 7 months of age by changes of position or removal of light (benign setting-sun phenomenon). The benign form might represent immaturity of the reflex systems controlling eye movements.> When persistent, this sign is one of the most frequent markers of elevated intracranial pressure, appearing in 40% of children with hydrocephalus (of any cause) and in 13% of patients with ventriculoperitoneal shunt dysfunction. It is an earlier sign of hydrocephalus than enlarged head circumference, full fontanelle, separation of sutures, irritability or vomiting. Consequently, this sign is a valuable early warning of an entity requiring prompt neuroimaging and urgent surgical intervention.">