In patients with large or small eyes, the clinical symptoms are usually accompanied by a sunken eye socket, resulting in a small or large eye. In 1/3 of patients with large or small eyes, the ptosis is caused by an injury, including a car accident, or an injury to the levator muscle during eyelid surgery. In the other 2/3 of cases, the eyelid muscle degenerates or regresses due to disease, including congenital underdevelopment of the levator muscle and acquired weakness of the levator muscle fascia, causing the upper and lower eyelid fissures to vary in width, resulting in large and small eyes. Usually, the eyelid muscle repair surgery or eyelid fascial crease surgery is used to correct this condition. When performing an eyelid surgery, it is important to identify the thin levator muscle before performing the crease correction surgery. Typically, if there is a 0.1 cm difference in the size of the two eyes, the correction must be 4 times larger, meaning that the folds of the levator muscle must be raised to 0.4 cm, but it will take at least one to two months after the surgery for the two eyes to balance.