The hallmark of Duane's syndrome is retraction of the eyeball during attempted adduction, caused by simultaneous contraction of the internal and external rectus muscles.
The horizontal deviation varies in the primary position of the eyes, downward or upward gaze, regardless of whether the strabismus is concomitant or paralytic.
Nystagmus is a severe form of oculomotor disorders, manifested in spontaneous oscillatory movements of the eyes and accompanied by a significant decrease in visual acuity - low vision. The development of nystagmus can be caused by the influence of central or local factors.
One of the most frequently occurring sensory disturbances in unilateral strabismus is amblyopia, i.e. functional reduction of vision of the eye due to its inactivity, disuse.
