Corneal contact lenses fabrication procedure - involves calculation of cornea curvature and radius to establish lens profile with allowance for tear film thickness

摘要

A method is used for the fabrication of a corneal contact lens (L). A reference plane (Y) is first established which contains the iris (S3). From this plane a vertical curve across the outer surface of the cornea is defined and curvature and radius determined. In a latter stage an allowance for the lacrynal film thickness is made and the characteristics of the concave face of the contact lens established to define a second curve parallel to the first. Using these parameters the lens is constructed and modified for the degree of optical corrections required by the patient.