三维人体测量学, 　下睑特征, 　年龄, 　性别

Objective To provide comprehensive anthropometric data on the lower eyelid region among different age and gender groups of Chinese individuals through three-dimensional imaging analysis. Methods Sixty-two healthy subjects aged 20-35 and 50-65 were recruited to acquire their three-dimensional facial images. Utilizing 27 landmarks， a total of 37 lower eyelid measurement indicators were established， comprising of 21 straight lines，5 curvatures，4 angles，2 areas， and 5 ratios. The age and gender characteristics of the lower eyelid were summarized by comparing the measurement results among different age groups and gender groups. Results Compared to females， longer palpebral fissure， lower tear troughs and lidcheek junction， smaller inner and outer canthal angles， as well as a larger area and proportion of the lower eyelid region were found in males. With aging， there is a gradual reduction in the height of the palpebral fissure and inner canthal angle，accompanied by sagging of the tear trough and lid-cheek junction， enlargement of the lower eyelid area， and swelling of the lower eyelid. Conclusion The proportion of the eyebrow-eye unit occupied by the lower eyelid region is greater in males than in females. In elderly individuals， there is a noticeable sagging of the tear trough and lid-cheek junction， accompanied by swelling of the lower palpebral region. These findings can serve as a valuable reference for cosmetic procedures and oculoplastic surgery.

Three-dimensional anthropometry, Lower eyelid characteristics, Age, Gender