Double eyelid surgery, also known as blepharoplasty, is the surgical alteration of the skin and subcutaneous tissues of the upper eyelid to turn the original single eyelid into double eyelid or to improve the appearance of an undesirable heavy eyelid. It is indicated for: 1. healthy, mentally normal monolids who actively request surgery without contraindications; 2. monolids with bloated upper eyelids (commonly known as blister eyes); 3. monolids with medial canthus; 4. mild upper face entropion; 5. mild upper face ptosis (combined with upper eyelid muscle shortening); 6. loose, sagging upper face skin that affects the visual field. Mostly seen in the elderly; 7. One single and one double in both eyes, single lid side can be operated. Or both eyes have different widths of creases and different sizes of lid fissures; 8. Internal double or hidden double where the heavy lids are not obvious when the eyes are open. The age at which blepharoplasty should be performed is usually not too early, because eyelids change a lot in early childhood, sometimes single and sometimes double, so it is better to wait until around puberty before considering surgery. Pre-operative preparation: 1. If you have conjunctivitis, blepharitis, or severe trachoma, you must be cured before surgery. If there is inflammation around the eye, surgery should be postponed. Antimicrobial eye drops should be administered twice a day before surgery. 2. For patients with a history of bleeding tendency, platelets and blood clotting time should be checked. 3.Middle-aged and elderly patients should have their blood pressure measured and electrocardiogram done if necessary, and if there are mild abnormalities, symptomatic medication should be administered before surgery. 4.Avoid menstrual period to perform surgery. 5.Pre-pregnancy (third trimester) or late pregnancy (third trimester) surgery should be suspended. 6. Stop taking steroids and anticoagulants such as aspirin 7-10 days prior to surgery. There are dozens of surgical methods for blepharoplasty, but they can be summarized into three categories: 1. Incisional lid fixation It is the oldest method of blepharoplasty because it regulates and changes the tissue structure at all levels of the upper lid and can address many of the complex problems that exist in the eye face, such as lax upper lid skin, eyelash entropion, upper lid bloating, sagging orbital fat, septum laxity, and bulging outer upper face margin. The result is a solid and long-lasting heavy face with deep creases and a three-dimensional appearance. The disadvantage is that the procedure is complex, requiring familiarity with eyelid anatomy and a solid base of plastic surgery practice. After surgery, the scar of the incision line is more obvious within 3-6 months, gradually fading with time, edema can often be detected one month after surgery, but by 2 months or more after surgery, more already looks natural. 2. The buried wire method is suitable for young people with large lid fissures, thin eyelids, no bloating, no laxity of the eyelid skin, normal tension, and no canthus. The advantages are that it is simple to perform and easy to master. The ligature is fixed between the upper eyelid dermis and the anterior or superior edge of the face plate, resulting in a natural-looking crease. There is no incision and the post-operative tissue reaction is minimal and does not interfere with work, making it easy to accept. If the beginner does not master the technique properly, the original method can be used or the incision method can be used to make up for the failure without leaving any sequelae. The disadvantage is that the upper lid crease can easily become shallow and narrow. The upper lid crease can disappear if the case is not properly selected or if the technique is not well mastered. The knot can be easily loosened, leading to surgical failure. The nodes are too shallow and can easily become exposed or form small cysts. Case selection is narrower than with the incision method. If the upper lid is mildly bloated and the patient is adamant about the buried wire procedure, a small incision can be made in the outer 1/3 of the upper lid crease to remove the orbital fat. 3. Sutures (also known as penetrating sutures) are suitable for those with large lid fissures, thin faces, no bloating, no laxity or mild laxity of the upper lid skin and no medial canthus. The advantage is that it is simple to perform and easy for beginners to master. No incisions are made and there are no visible scars after surgery, making it easy for the patient to accept. The disadvantage is that because the entire eyelid tissue is ligated and lymphatic flow is impaired, postoperative reliance on tissue response to the sutures results in an oblique fibrous adhesion between the levator aponeurosis and the skin at the upper edge of the lid, but often the fibers formed are not uniform. Once the scar has relaxed, the crease becomes shallow or disappears. In many cases, the crease is often too high and difficult to lower. If the ligature is too high, it can restrict the mobility of the levator and Muller muscles, resulting in ptosis, eye fatigue, and difficulty in opening the eyes. It is not possible to remove loose upper lid skin and orbital fat at the same time.