Patent ID: 8521318

Claim:
A method of producing an ophthalmic element, comprising: providing a model cornea, the model cornea characterized by one or more of: an aspheric profile along a first meridian of the model cornea that is different from an aspheric profile along an orthogonal second meridian of the model cornea; one or more of fifth-order, seventh-order, and ninth-order aberrations; and an asphericity of a first zone of the model cornea that is different from an asphericity of a second zone of the model cornea surrounding the first zone; providing a model ophthalmic element disposed about an optical axis having a primary meridian and an orthogonal secondary meridian, the model ophthalmic element comprising an anterior surface and an opposing posterior surface, the model ophthalmic element characterized by a higher order toric shape imposed on one of the surfaces, the higher order toric shape including a first profile disposed along the primary meridian and a second profile disposed along the secondary meridian that is different in shape from the first profile, the higher order toric shape being characterized by a profile along at least one meridian that changes with increasing radius from the optical axis raised to a power that is greater than two; providing a merit function representative of the optical performance of a system including the model cornea and the model ophthalmic element; selecting a value of a first coefficient of an equation characterizing the higher order toric shape of the model ophthalmic element; calculating a value of the merit function based on the value of the first coefficient and determining whether the value of the merit function is above a predetermined value; repeating selecting a value of the first coefficient and calculating a value of the merit function until the merit function is above the threshold value; and producing a physical ophthalmic element based on a value of the first coefficient that causes the merit function to be above the threshold value.