Cone-shaped cornea refers to the developmental abnormality of cone-like protrusion of the cornea and thinning of the corneal stroma in the hemiprotrusion area, which usually manifests as follows: 1. central or paracentral cone expansion of the cornea, 2. cone shape varies as round or oval, 3. thinning of the corneal stroma is most obvious at the tip of the cone, 4. severe irregular astigmatism, high myopia, and severe vision loss. Our hospital encountered a patient with severe cone cornea successfully RGP correction case to share with you. Case: XX patient, male, 25 years old, found vision loss for six months, diagnosed cone cornea disposal RGP fitting treatment. The topographic map of the right eye shows the following characteristics: the cone shows a “crater”-like change, the curvature around the “crater” is higher and steepest ≥ 80D, “crater “In this case, a cone lens with a steeper base arc should be used. Topography of the left eye shows characteristics: papillary cone cornea at the bottom Steepest curvature ≥ 70 D, again requiring a cone lens with the steepest base arc. Due to the high corneal curvature of the patient, which is a severe conical cornea, we used the “three-point contact” design of the conical lens for correction. The main feature is that the central part of the lens is in light contact with the top of the cone, with a small amount of fluorescein in the central part of the lens on the periphery of the cone, and the peripheral part of the lens has a suitable edge to ensure sufficient tear exchange under the lens. The lens is well positioned centrally, with a suitable degree of mobility, without friction on the corneal apex, and with good corrected visual acuity, tolerated by the patient. This fitting relationship improves the stability of the lens and increases the comfort of wearing the lens, while effectively ensuring good tear exchange under the lens, allowing the RGP to maintain good mobility while reducing direct contact with the weak corneal cone apex, reducing complications and improving patient safety. The right eye was tried on a total of three times to determine the parameters. In the first trial, the BC5.0 parameter with a flatter base arc showed clear fluorescence staining of the cone apex, slightly wider peripheral edge warping and poor stability, and the lens was flat, so the lens was tightened. Choose the base arc parameters similar to the level of the lens BC4.9 observation, found that the cone top contact area is still clear side warp slightly wide lens slightly flat, again tightened. Again, ЫBC4.8 showed that the fitted lens was in slight contact with the cone apex, with a little fluorescence in the center of the paracentesis within the ideal range, but the edge warp was <0.2, which was not conducive to the exchange of tears under the lens, so the custom-made lens was raised on the basis of the edge warp of the previous trial lens. The result: OD KONE 4.7 -34.75D 8.5 A18 BCVA 0.6 The left eye was treated with a lens with a base arc of 5.4, and the edge warp was reduced because the edge was slightly wider than 0.7. The central area of the corneal contact lens was in slight contact with the corneal apex with a few tears and a tear collection in the paracentral area Within the accepted range, the lens was in slight contact with the cornea, with ideal wide spread of the marginal arc and ideal warp height at the edge, with normal tear exchange. The result: OS KONE 5.4 -26.25D 8.5 A18 BCVA 0.5 The patient had good results with the custom-made lenses, and the naked vision of both eyes reached the expected result. Since this patient has a severe cone cornea, we would like to emphasize his regular review and advise him that he should not wear the lenses at night overnight.