As a transparent avascular tissue located at the front of the eyeball,the cornea is an important barrier to external damage.Both epithelial and endothelial cells of the cornea harbor primary cilia,which sense changes in the external environment and regulate intracellular signaling pathways.Accumulating evidence suggests that the primary cilium regulates corneal development in several ways,including participation in corneal epithelial stratification and maintenance of corneal endothelial cell morphology.In addition,the primary cilium has been implicated in the pathogenesis of several corneal diseases.In this review,we discuss recent findings that demonstrate the critical role of the primary cilium in corneal development.We also discuss the link between ciliary dysfunction and corneal diseases,which suggests that the primary cilium could be targeted to treat these diseases.