[Gas permeable contact lenses in the management of problem cases and in prolonged wearing time].

The continuous improvement of contact lenses (copolymers with high gas permeability) makes better care possible in problem cases. They can also be used for continuous wear. The present authors report upon 104 cases in which a contact lens made of P3, was tested. This is a hard, flexible contact lens with a DK value of 33, which is produced without additional treatment of the surface.