Patients with myasthenia gravis present with droopy eyelids, indicating involvement of their levator muscle. Myasthenia gravis is an acquired autoimmune disease, mostly caused by autoimmune dysfunction induced by viral infections. The lesion is located at the neuromuscular junction, and the immune abnormality causes damage to the acetylcholine receptors on the postsynaptic membrane of the neuromuscular junction, resulting in dysfunction of the transmission of the neuromuscular junction, causing generalized or partial skeletal muscle weakness. Myasthenia gravis is characterized by a marked morning lightness and pathological fatigue, with symptoms decreasing at rest and increasing after activity. Patients with drooping eyelids may have involvement of the levator muscle and may also have generalized muscle weakness or other extraocular muscle involvement. When observing a patient’s symptoms, it is important to determine the degree of ptosis, whether it is obscuring the superior pupillary margin or the superior corneal margin.