[As yet unknown sign in internuclear ophthalmoplegia: unilateral eyelid retraction occuring during abduction or adduction of the eye bulb].

The author presents 2 cases of internuclear ophthalmoplegia with unilateral upper lid retraction and widening of the palpebral fissure of the adducted eye with a simultaneous narrowing of the palpebral fissure of the other eye. In the 3rd case of internuclear ophthalmoplegia with paralysis of the lateral rectus muscle, the sign of upper lid retraction was present in the adduced eye.