Fig. 18. Electro-oculographic recording in patient with unplanned disinsertion of the superior rectus muscle. Upward (U) saccades are moderately reduced in speed, whereas downward (D) saccades are normal. Upper tracing: eye position; lower tracing: peak velocity. (Rosenbaum AL, Metz HS: Diagnosis of lost or slipped muscles by saccadic velocity measurements. Am J Ophthalmol 77:215, 1974. Published with permission from the American Journal of Ophthalmology. Copyright by the Ophthalmic Publishing Company)