Marcus Gunn described for the first time a syndrome consisting of unilateral, congenital ptosis and rapid, exaggerated elevation of the ptotic eyelid on movement of the mandible to the contralateral side. The clinical findings and management of 2 patients with Macus Gunn phenomenon had been reviewed. Preoperative measurement of ptotic amount, levator function by Berke's method, and marginal limbal distance were evaluated. The amount of winking of the upper eyelid on primary gaze was graded on a scale from I to III. The operation was performed two patients under local anesthesia, one by unilateral levator resection, one by orbicularis oculi muscle flap. As a result, the correction of blepharoptosis was possible without severe complicatoins.
  However, moderate degree of jaw-winking, slight undercorrection, transient lagophthalmos was inevitable.
  The management of patients with Marcus Gunn phenomenon is a challenging endeavor. Therefore, a comprehensive medical and ophthalmological evaluation of the patient and a detailed history are mandatory before undertaking the successful treatment of patients with this syndrome.