UNIVERSAL CONTACT LENS POSTERIOR SURFACE CONSTRUCTION

摘要

The carrier region extending beyond the optical portion of a contact lens overlying the cornea of an eye can be modeled in one universal shape that will fit all eyes. That shape is characterized by a curve of radius of curvature versus distance from the High point which is substantially linear with a first slope below a 10mm diameter of the eye as projected onto a plane perpendicular to the optical axis, is substantially linear above 10mm with a second slope which is substantially greater than the first slope, and which has an inflection point in the vicinity of approximately 10mm. Preferably the first linear portion has a radius of curvature of approximately 7.6 mm at a diameter of about 7mm, with a slope of about.13 (the first slope) and a radius of curvature of about 9mm at a diameter of 12mm, with a slope of about.45 (the second slope).