Oxygen permeability

Oxygen permeability (OP) is a parameter of a contact lens. OP expresses the ability of the lens to let oxygen reach the eye by diffusion. Another parameter is the transmissibility level (abbreviated DK/t), the Dk per thickness of the lens, and is generally more used. In soft contact lenses, it is dependent on the thickness of the lens and the material of the lens, especially concerning the water content.