Ptosis can be caused by mechanical factors, decreased muscle strength and congenital ptosis. 1. Mechanical factors: Because of edema or mass growth in the upper eyelid, possibly due to excessive fat accumulation, the levator muscle is unable to withstand it, so that ptosis occurs. 2. Muscle weakness: The first symptom of muscle weakness, or myasthenia gravis, is ptosis of the upper eyelid. 3. Congenital ptosis: Ptosis is mainly due to dysplasia of the nucleus accumbens or the levator ani muscle, and is either autosomal dominant or recessive. There are other reasons for ptosis, patients should go to the hospital in time for appropriate examination when ptosis occurs, to clarify the cause of the disease and actively cooperate with the doctor’s treatment.