Upper eyelid feeling unable to open may be caused by palsy of the motor nerve, myasthenia gravis, eye inflammation and so on. 1. If an adult suddenly develops ptosis, it may be due to ocular trauma or intraocular swelling compressing the motor nerve palsy, resulting in damage to the levator muscle and weakness of the upper eyelid. 2. Autoimmune abnormalities due to environment, infection, etc. Autoantibodies attack neuromuscular junction receptors, affecting neuromuscular conduction, thus causing generalized myasthenia gravis, which involves the eye manifested as eyelid weakness and inability to open. 3. Bacterial infections leading to keratitis, conjunctivitis, and inflammation of the eyelids such as blepharitis, causing redness, swelling and pain of the upper eyelid, pressure on the surface of the eye, can also lead to difficulties in opening the upper eyelid. When the upper eyelid can not be opened for a long time, it is recommended to go to the regular hospital for examination, to clarify the cause of the disease, for the cause of the treatment, so as not to delay the condition.