Because of the inextricable link between the eyes and headaches, ophthalmologists are often the first physicians to evaluate patients with headaches, eye pain, and headache-associated visual disturbances. Although ophthalmic causes are sometimes diagnosed, eye pain and visual disturbances are often neurologic in origin. Many primary headache disorders have ophthalmic features, and secondary causes of headache frequently involve the visual system. Both afferent and efferent symptoms and signs are associated with headache disorders. Moreover, the frontal or retro-orbital pain of some primary ophthalmic conditions may be mistaken for a headache disorder, particularly if the ophthalmologic examination is normal. This article reviews common ocular conditions that are associated with head pain, and some secondary causes of headache with neuro--ophthalmic manifestations.