Patent ID: 7097302

Claim:
A rigid gas permeable (RGP) contact lens for wearing on a post-transplant cornea of a patient's eye, where the post-transplant cornea has a corneal astigmatism of at least 3.0 diopters, an annular surgical junction with a median diameter of about 8 mm and a region of traumatized tissue extending radially outward from the surgical junction, the contact lens comprising: a lens body formed of a rigid gas permeable material having an anterior surface adapted to face away from the post-transplant cornea, a posterior surface adapted to face toward the post-transplant cornea, and an overall diameter within the range from about 9.5 mm to about 10.4 mm; the posterior surface having a circular optical zone disposed in its center spanning the region of traumatized tissue, an annular secondary zone coupled to the optical zone and extending radially therefrom across the region of traumatized tissue, and an annular peripheral zone coupled to the secondary zone and extending radially therefrom; the optical zone having a diameter within the range from about 7.7 mm to about 8.9 mm, and having a spherical, rearwardly concave curvature with a constant radius of curvature within the range from about 7.3 mm to about 8.2 mm; the secondary zone having a radial width on each side of the optical zone within the range from about 0.2 mm to about 0.3 mm, and having an aspheric, rearwardly concave curvature with a radius of curvature that varies continuously as it transitions between the optical zone and the peripheral zone; and the peripheral zone having a radial width on each side of the secondary zone within the range from about 0.3 mm to about 0.5 mm, and having a spherical, rearwardly concave curvature with a constant radius of curvature within the range from about 11.0 mm to about 13.0 mm; wherein, when the tens is positioned on the post-transplant cornea such that the peripheral zone is disposed radially outside the region of traumatized tissue, the peripheral zone will adhere to the cornea with a relatively thin tear film while a relatively thick tear film will be trapped between the optical zone and the cornea and maintained by sealing action of the secondary zone.