×

Toric optic for ophthalmic use

  • US 8,521,318 B2
  • Filed: 08/31/2012
  • Issued: 08/27/2013
  • Est. Priority Date: 02/25/2010
  • Status: Active Grant
First Claim
Patent Images

1. 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.

View all claims
  • 2 Assignments
Timeline View
Assignment View
    ×
    ×