Cone keratoconus is a common dilated corneal disease. Cone cornea is an eye disease characterized by a dilated, centrally thinned cornea that protrudes forward in a conical shape. It often results in highly irregular myopic astigmatism, and in advanced stages, acute corneal edema, scarring, and significant vision loss. It mostly develops in adolescence, usually anterior and posterior to both eyes, and progresses slowly. Therefore, if one eye is diagnosed with cone keratoconus, then if the other eye has myopia and astigmatism, the possibility of cone keratoconus is considered. The etiology is unknown, and more scholars believe that the disease is autosomal recessive. Histologically, there is a decrease in the number of fibrous laminae in the cone, but the diameter of collagen fibers has not changed, so it is thought that the fibrous laminae may not be bonded enough to each other, and the laminae may slip away from each other, resulting in thinning. Genetic and allergic diseases are also possible triggers. It can lead to severe irregular astigmatism and high myopia with severe loss of vision. Depending on the progression of the disease, it can be corrected by glasses alone in the early stages of the disease. When the corneal surface becomes irregularly astigmatic, contact lenses should be required. Currently, it is usually corrected by RGP (a kind of contact lens), but RGP cannot stop the progression of the disease, and corneal transplantation is needed when RGP cannot be worn or corrects poor vision.