Orthokeratology lenses are made of highly oxygen-permeable polymer materials. Different varieties of different companies may use different materials, but they all need to meet the physical and chemical requirements of high oxygen permeability, appropriate elasticity, toughness, sufficient surface wetness, and surface hardness. Materials such as glass or plain plexiglass are not oxygen permeable and cannot be used to make orthokeratology lenses.
Orthokeratology is a physical treatment process, which acts on the corneal epithelium, only rearranges the distribution of corneal epithelial cells, and then changes the curvature of the cornea; therefore, it does not cause substantial changes to the physiological structure and performance of the cornea.
Within 30 days after you stop wearing it, the distribution of corneal epithelium and the curvature of the cornea will return to their original state, so there will be no sequelae.