Ocular ptosis, or drooping of the upper eyelid, has diverse etiologies, including neurologic and non-neurologic causes. Aponeurotic ptosis is a common cause in the elderly and traumatic or mechanical causes can affect any age, mimicking a neurologic cause. The neurologic causes are diverse but especially arise peripherally from pathologies affecting the nerve, neuromuscular junction, and muscles. The choice of treatment depends on the particular cause, but surgical intervention can also be an option in appropriately selected neurological patients whose ptosis remains embarrassing despite the best medical treatment. Myasthenia gravis, an autoimmune disorder targeting the neuromuscular junction, is a significant cause of ocular ptosis. The treatment is mainly by symptomatic and immunosuppressive medications, but surgical interventions, such as blepharoplasty, may be considered in some cases of socially embarrassing ptosis.