The red reflex.

Eliciting the red reflex is a useful clinical test that can be easily performed in the pediatric emergency room. A direct ophthalmoscope is the only tool needed to perform this test. The test is non-invasive, making it a quick screening tool for even the most apprehensive child. A normal red reflex can rule out intraocular pathology; an abnormal reflex can indicate need for urgent ophthalmologic referral. The differential diagnoses for an absent (or black) reflex; an abnormally sized, shaped or positioned reflex; leukocoria; as well as a non-homogenous reflex are listed.