Open fan double eyelid is a more common type of double eyelid surgery, generally starting from the inner canthus of the upper eyelid skin fold or near the inner canthus and gradually moving upward away from the lid margin, from narrow to wide, like a folding fan opening, also known as wide tail type. Simply put, open fan double eyelids are those where the width of the inner eyelid is smaller than the width of the outer eyelid, and are suitable for candidates with a moderate distance between the eyebrows and the eyes and thin upper eyelids. Because the eyelids are thinner, the upper part of the eyelids will be more natural and have a more radiant look, which is widely appreciated by young women in their 20s and 30s. Scalloped double eyelids require a higher level of operation from the surgeon. For the inner corner of the eyes, the surgeon needs to handle and grasp more precisely. If not handled properly, the candidate may become an inner double eyelid after surgery, making it difficult to achieve the desired cosmetic effect. Therefore, candidates need to have a more careful consideration of the hospital, the doctor’s qualification and the doctor’s aesthetic level before surgery, and should not blindly undergo double eyelid surgery.