Conjugacy of eyelid movements in vertical eye saccades.

Purpose. To examine the conjugacy of lid saccades in normal subjects.Methods. Saccades of both upper eyelids were recorded simultaneously by means of small,lightweight, magnetic search coils, fixed on each lid. Subjects then made vertical eye saccadesbetween fixed targets. The associated eye saccades were recorded simultaneously by meansof magnetic search coils. The authors further examined whether the position of the lid coilsaffected the recordings.Results. Lid saccades were not as conjugate as their associated eye saccades. Nonconjugacy oflid saccades averaged approximately 8% of the target amplitude, irrespective of saccadicdirection. By contrast, nonconjugacy of the associated eye saccades averaged approximately1% of the target amplitude. Coil position significantly (P < 0.05) affected the recordings.Conclusions. Lid saccades are not as conjugate as their associated eye saccades. Coil positionis critical for the recordings of lid saccades. Invest Ophthalmo 1995l Vi 36:2686-2694;s Sci. .15ecker and Fuchs