With the popularity of corneal contact lenses, the incidence of resulting keratoconus is increasing each year. Because the interaction between the lens and the corneal surface in the case of wearing corneal contact lenses interferes with the physiological activity of normal corneal tissue. It mainly causes corneal hypoxia, hypercapnia, instability of the tear film, mechanical damage, and acute inflammation. About 90% of the oxygen supply to the cornea is obtained from the atmospheric environment. The current corneal contact lenses, regardless of the material, will reduce the oxygen content of the cornea by 8% to 15%. Long-term wearers mainly cause a series of eye symptoms caused by chronic corneal hypoxia, hypercapnia and inflammation. The clinical manifestations of corneal contact lens keratitis caused by wearing keratocontact lenses are: 1. superficial punctate keratopathy: due to hypoxia and hypercapnia resulting in reduced metabolic rate of corneal epithelium, reduced oxygen uptake, reduced ion pump function and enzymatic activity, epithelial morphological changes, microcystic vesicles, corneal neovascularization and corneal hypoesthesia are common. Corneal epithelial microvesicles are the prominent manifestation of epithelial growth abnormalities caused by chronic corneal hypoxia. Microcystic vesicles disappear after removal of corneal contact lenses and generally do not affect visual acuity. Due to hypoxia and inflammation, punctate, linear, bowed and diffuse clouding of the corneal epithelium is seen. Corneal neovascularization is also mainly caused by contact lens-induced corneal hypoxia, excess lactic acid, and softening of the corneal stroma. Commonly seen in overnight lens wearers. 2, abnormalities in the corneal stroma: there can be acute inflammatory manifestations such as corneal stromal softening, streaks and folds in the corneal stroma and corneal edema. And long-term wearers (several years) can appear corneal stromal thinning. 3, abnormalities of the corneal endothelium: long-term chronic hypoxia interferes with the stability of corneal endothelial cells, and the morphology and number of endothelial cells decline. 4, corneal contact lens-induced infection: long-term wear lenses make changes to the eye surface, local resistance, coupled with the contamination of the lens itself, the operation of inadvertent scratching of the corneal epithelium, prompting the attachment and proliferation of microorganisms, triggering infection. Treatment principles: corneal lesions caused by corneal contact lenses, once found, the contact lenses should be removed immediately, using antibiotic drops frequent eye dots to prevent infection. If corneal neovascularization occurs then apply glucocorticoids or non-steroidal anti-inflammatory drugs. If the corneal endothelium has changed and the number has decreased significantly, it should be changed to wearing frame glasses. For corneal infection that has been caused, treat as infectious keratitis.