The best age for double eyelid surgery is adulthood. Usually, cosmetic surgery is performed on mature individuals. Due to the development of the human body, the development of the eyes does not stop until adulthood, when the anatomical functions of the eyes are well developed and the postoperative results are stable, with no functional effects, so the age for double eyelid surgery should, in principle, meet the requirement of at least 18 years of age. Nowadays, the demand for cosmetic results is gradually becoming younger and younger, and some candidates may ask for double eyelid surgery when they are 16 or 17 years old. In this case, an individual analysis should be made with the doctor’s judgment and advice. If the patient is relatively mature and has a stable facial condition, and if the individual or the parents are more eager to have the surgery, the double eyelid surgery can be carried out with the parents’ signature and approval. For older patients, if there is a more pronounced sagging of the skin under the eyes, double eyelid surgery can be performed to remove the excess sagging skin in order to achieve a rejuvenating effect.