“…The pathogenesis of lid lag in thyroid-associated ophthalmopathy may be due to the mechanical limitation of the levator muscle resulting from infiltration and shortening. Transient eyelid lag has been reported in myasthenia gravis patients [6,7] suggesting that transient eyelid lag in myasthenia gravis could result from transient levator palpebrae muscle contracture, myotonia, or posttetanic facilitation. However, these cases exhibited eyelid lag lasting only for a few seconds, and therefore, cause of eyelid lag in these cases seems significantly different from that in our patient who exhibited eyelid lag for 2 months.…”