Patent ID: 7625086

Claim:
A method for designing a multifocal contact lens pair, comprising the steps of: (a.) providing a first lens design for a dominant eye of a lens wearer and a first lens design for a non-dominant eye of the lens wearer; (b.) selecting a first weighting function that is a function of a first neural contrast sensitivity function for application to the dominant eye lens design and a second weighting function that is a function of a second neural contrast sensitivity function for application to the non-dominant eye lens design; (c.) using the first weighting function for the first lens design and the second weighting function for the second lens design in a performance prediction models for each of the first and second lens design, wherein the performance predictive model correlates measured performance for two or more lens designs with predicted performance for each of the first and second lens designs; and (d.) using the results obtained in step (c.) to optimize the first and second lens design; wherein step (c) further comprises: (i) calculating a predicted visual performance using the prediction model by first calculating a weighted area of an optical transfer function according to the following equation: WA OTF = ∫ m ⁢ ⁢ i ⁢ ⁢ n ma ⁢ ⁢ x ⁢ OTF ⁡ ( v , D , V ) × [ object ⁢ ⁢ contrast × NCSF ⁡ ( v , D , V , L ) ] N ⁢ ⁢ ⅆ v wherein: max and min define a frequency range over which the integration is performed; OTF is the optical transfer function calculated for the lens design at a retinal plane; v is a spatial frequency expressed as line pairs or cycles per degree of subtended angle at a fovea; D is a pupil diameter in millimeters; V is a vergence; object contrast is a value between 0 and 1 that represents a contrast of an object being viewed; NCSF is the neural contrast sensitivity function; L is a luminance of a room expressed in candelas/m 2 ; and N is an exponent with a value from 1 to −2 and (ii) correlating the WA OTF to a measured visual performance of the two or more lenses.