eye deviation [AS, eage + L, deviare, to turn aside] , 1. a movement of one or both eyes, singly or jointly, from the median line or from the original direction of fixation. Manifest deviation is the number of degrees by which the visual axis of one eye deviates from that of the other in cases of squint, when both eyes are open. 2. (in strabismus) the departure of the foveal line of sight of one eye from the point of fixation.
