Ptosis with weakness of orbicularis- oculi is an early feature of-
Fisher syndrome
Myasthenia gravis
Eaten lambert syndrome
Thyrotoxicosis
Myasthenia gravis is a major cause of ptosis & diplopia. The distribution of muscle weakness has a characteristic pattern. The cranial muscles particularly the lids and extraocular muscles are often involved early in the course of MG, and diplopia and ptosis are common initial complaints.