The eyelid is formed when the levator muscle is attached to the upper edge of the eyelid plate and some fibers are attached to the upper lid skin at the crease of the eyelid through the orbital septum and orbicularis muscle. 2. The advantages of double eyelids (1) The eyelid fissure is long and wide, in line with aesthetic proportions, while the single lid fissure is short and unattractive. (2) The eyelids give a sense of vitality, while single lids often have sagging upper lid skin, giving a sense of lethargy. (3) Most eyelids are thin and both eyes are flexible and shiny, while single-lidded people have swollen upper lids and appear bulky, fatigued and sleepy. (4) The eyelashes are long and dense, upright or upturned, looking beautiful and moving; while single-lid eyelashes are short and small, and sagging, showing both eyes bland and lifeless. 3. Indications for double eyelid surgery (1) Single-lidded people. (2) One eye with a single lid and the other eye with a double lid. (3) Double eyelids with different widths and asymmetries in both eyes. (4) Narrower heavy eyes that require widening. (5) Multiple folds in the heavy lids with unattractive appearance. (6) Loose skin on the upper eyelid with a “triangle eye”, “eight-eyed” or “squinting eye” appearance. (7) Those who want to modify their eyelids after blepharoplasty because they are unattractive and unsatisfactory. (4) Contraindications to double eyelid surgery and all subsequent cosmetic surgery (1) Severe liver, kidney, heart and brain diseases, pregnant women and patients with severe blood disorders. (2) Women who are in menstrual period. (3) Those with psychiatric disorders, psychological disorders or excessive or unrealistic demands. (5) Those with obvious scarring. (6) Those who have skin inflammation lesions at the operation site. 5, double eyelid surgery methods (1) buried wire method Advantages: suitable for young people, mainly those with non-loose upper lid skin, not much fat and thin eyelids, light surgical swelling, little injury and fast recovery. Disadvantages: Easy to cause adhesion failure and not suitable for swollen eyes. (2) Incision method Advantages: wide range of indications, good surgical results, ability to cut away skin and fat, long lasting effect of blepharoplasty. Disadvantages: It takes 1-3 months to recover naturally (depending on the individual’s physical condition). (3) Korean 3-point minimally invasive method Advantages: wide range of indications, excellent surgical results, short recovery period, natural recovery, and long-lasting blepharoplasty effect. Disadvantages: Not suitable for people with thick eyelids and more fat in the eyelids.