The child was an 11-year-old male. When orthokeratology lens was fitted, corneal abnormalities were found for 1 day, and I went to the Department of Keratology, Beijing Tongren Eye Center, Beijing Tongren Hospital affiliated to Capital Medical University. Eye examination: visual acuity was 0.6 for the right eye and 0.8 for the left eye; There are many small patches of opacity in the elastic layer of the posterior cornea of the left eye, mainly distributed in the peripheral part of the cornea; Vesicles can be seen inside the opacified area, and the vesicles are more obvious after dilating the pupil by retinal reflection illumination (Quintessence Picture 1In a); A "double track" sign can be seen in the right eye (Quintessence Picture 1In B). Ocular examination of the father of the child: Scattered small patches of opacity were seen in the elastic layer of the posterior cornea of both eyes, and no "double track" sign was seen. OVOL2, COL8A2, ZEB1 and GRHL2 gene tests in children and their fathers were negative. Clinical diagnosis of the child: polymorphic corneal dystrophy in the posterior part of both eyes; Refractive error in both eyes.