Gas-permeable rigid contact lens for irregularly deformed cornea

摘要

The lens (L) for contact with the cornea (C) has an inner radius of curvature (R1) of its peripheral portion which is shorter than the radius (R2) of the adjacent inner face and that (Ro) of its centre.The inner peripheral portion is in the shape of a portion of a torus. Such a lens can be made to measure from the results of kerato-analysis esp. when the corneal deformation cannot be compensated fully by other means.