Fig. 11. Electro-oculographic recording of vertical saccades in a patient with an orbital floor fracture. Upward (U) saccades are rapid, whereas downward (D) saccades are slow, indicating inferior rectus weakness. Upper tracing: eye position; lower tracing: peak velocity. (Metz HS, Scott WE, Madson E et al: Saccadic velocity and active force studies in blowout fractures of the orbit. Am J Ophthalmol 78:665, 1974. Published with permission from the American Journal of Ophthalmology. Copyright by the Ophthalmic Publishing Company)