Primary cone cornea is considered an autosomal recessive disorder that occurs during the growth spurt with a hemispherical dilated cornea and a corneal curvature of up to 50 D. In the early stages, it can be corrected with normal glasses, but as the disease progresses, normal glasses are no longer effective. However, since the introduction of RGP glasses, some patients with early detection of cone-shaped corneas have been able to control their condition by wearing these lenses. RGP lenses are the safest and most reliable way to treat cone-shaped corneas, as recognized by the world’s leading ophthalmologists. The Chinese name for RGP is rigid oxygen permeable contact lenses. As you can understand from the name, it is rigid, not soft like normal contact lenses, so the visual effect of RGP will not fluctuate like soft lenses. The biggest advantage of RGP lies in its high oxygen permeability system. The best soft lenses have an oxygen permeability coefficient (DK value) of just over 20, while RGPs have a minimum of 36, which determines how much oxygen the cornea can receive through the lens. This factor determines how much oxygen is available to the cornea through the lens. In addition, the RGP has a certain degree of mobility in the cornea, which allows different parts of the cornea to receive oxygen alternately and directly. The absence of oxygen in the cornea prevents many of the complications associated with soft lens wear. Long-term clinical practice has proved that for the same person and the same eye cornea, wearing general spherical lenses and RGP glasses compared, RGP glasses for astigmatism correction effect is far better than spherical lenses. Moreover, for patients with irregular astigmatism such as cone corneas, it is very difficult to correct with normal hydrogel lenses, and RGP lenses are the best choice for them. Because RGP has many diagnostic lenses with complex curved parameters for such patients, thus making lenses with special efficacy for cone corneas and ensuring comfort after wearing them.