 Mechanical ptosis can also occur due to scarring tissue restricting the patient's eyelid excursion or it could have potentially created a mass that are weighing down the patient's lid.Another mechanism can be explained due to the disturbance of the oculomotor nerve causing the levator palpebrae to weaken results in the eyelid being droopy.Ptosis can also occur in a patient with brain tumors due to the pressure of the third nerve or also known as the sympathetic nerve on the brain stem, causing the eyelid to droop.