There are many reasons why the eyelids may not close properly, as follows: 1. Congenital eyelid closure is common, and is caused by eyelid dysplasia at birth. 2. Neurological causes, such as facial nerve palsy, hemiplegia, facial palsy, and post-operative general anesthesia patients, may have this symptom, which is sleeping with the eyes open. 3. 3. traumatic eyelid defects, where trauma causes a defect in the upper or lower eyelid, can create the sensation of sleeping with the eyes open. 4. medical causes, such as double eyelid surgery, ptosis correction surgery, and some people want to open their eyes wider for beauty, which causes the sensation of sleeping with the eyes open. Mild cases of this symptom do not need to be treated, while severe cases tend to cause exposure keratitis and require medication or surgery.