Lines between the eyebrows (frown lines) and lines jutting from the corner of the eyes (crows feet) are believed to develop because of small muscle contractions.

• 面部肌肉收缩在眼眉(皱眉线)和眼睛(鱼尾纹)的外侧之间的皱痕是由于小肌肉收缩造成的。