Eyelid split nevus: This is also known as a mirror image nevus or a pair of kissing nevi because the upper and lower eyelid lesions are basically the same in size and color, and the eyelid and nest of nevus cells develop and fuse together at the same time during the eighth week of embryonic life. Treatment: Surgical removal and blepharoplasty. Due to the special structural shape of the eyelid, treatment of eyelid and lid margin masses is surgically difficult. After the swelling is removed, the five layers of the eyelid structure need to be finely aligned in layers according to the anatomy of the eyelid. This creates a beautiful, smooth eye curve, otherwise the incidence of post-operative complications such as angular deformity or inverted eyelashes is also greater and requires fine pre-operative design and intra-operative manipulation by an experienced specialist to minimize the risks.