Ptosis is generally caused by paralysis, damage or hypoplasia of the oculomotor nerve. Or because of acquired ptosis and genetic factors, ptosis. Light can cover some pupils, and heavy can cover all pupils. Moreover, it has a great influence on vision, and there is mechanical ptosis, which is caused by the pathological changes of eyelids themselves, leading to serious trachoma, trauma, inflammation, edema, elephantiasis and so on.