A method of producing a contact lens pair for a presbyopic patient, the lens pair comprising a first lens for a dominant eye and a second lens for a non-dominant eye, the lens pair having rotationally symmetric power profiles, the method comprising the following steps: determining the sphere prescription power Rx_sphere of the patient's eyes; determining the addition power Rx_add for providing near vision correction; determining the spherical aberration SA eye of the eyes; determining the lens fit F, being the change from nominal power of the eyes; calculating d and n; determining the contact lens pair by optimizing P(r) such that the following relationships are satisfied: D ̅ ≥ − 0.14 × Rx _ add + 0.84 N ̅ ≥ − 0.08 × Rx _ add + 0.64 Δ ̅ d = | d 1 − d 2 ̅ | ≤ 0.2 Δ ̅ n = | n 1 − n 2 ̅ | ≤ 0.2 wherein D is a mean value of a binocular weighted distance ratio for pupil diameters of about 2.5 to 6 mm, wherein the binocular weighted distance ratio is the maximum of the monocular weighted distance ratio of the dominant eye and the monocular weighted distance ratio of the non-dominant eye for a pupil diameter; wherein N is a mean value of a binocular weighted near ratio for pupil diameters of about 2.5 to 6 mm, wherein the binocular weighted near ratio is the maximum of the monocular weighted near ratio of the dominant eye and the monocular weighted near ratio of the non-dominant eye for a pupil diameter; wherein the monocular weighted distance ratio is calculated by integrating over the lens radius to give: d R = ∫ 0 R 1 − tanh 0.5 * | P r − Rx _ sphere | rdr ∫ 0 R rdr wherein the monocular weighted near ratio is calculated by integrating over the lens radius to give: n R = ∫ 0 R 1 − tanh 0.5 * | P r − Rx _ sphere − Rx _ add | rdr ∫ 0 R rdr Δ d is a mean value for a disparity at distance vision between the first and second lens for pupil diameters of about 2.5 to 6mm; Δ n is a mean value for a disparity at near vision between the first and second lens for pupil diameters of about 3.5 to about 6 mm; Rx_sphere is the sphere prescription power in diopters for the eye; Rx_add is an additional power in diopters added to a distance prescription to provide near vision correction for an individual; R is the radius of the pupil; wherein P(r) is the power of the lens plus eye given by P(r) = P CL (r) + SA eye * r 2 + F; P CL (r) is the power profile of the contact lens; SA eye is the spherical aberration of the eye; r is the radial distance from the centre of lens; and F is the lens fit. determining the sphere prescription power Rx_sphere of the patient's eyes; determining the addition power Rx_add for providing near vision correction; determining the spherical aberration SA eye of the eyes; determining the lens fit F, being the change from nominal power of the eyes; calculating d and n; determining the contact lens pair by optimizing P(r) such that the following relationships are satisfied: D ̅ ≥ − 0.14 × Rx _ add + 0.84 N ̅ ≥ − 0.08 × Rx _ add + 0.64 Δ ̅ d = | d 1 − d 2 ̅ | ≤ 0.2 Δ ̅ n = | n 1 − n 2 ̅ | ≤ 0.2 wherein D is a mean value of a binocular weighted distance ratio for pupil diameters of about 2.5 to 6 mm, wherein the binocular weighted distance ratio is the maximum of the monocular weighted distance ratio of the dominant eye and the monocular weighted distance ratio of the non-dominant eye for a pupil diameter; wherein N is a mean value of a binocular weighted near ratio for pupil diameters of about 2.5 to 6 mm, wherein the binocular weighted near ratio is the maximum of the monocular weighted near ratio of the dominant eye and the monocular weighted near ratio of the non-dominant eye for a pupil diameter; wherein the monocular weighted distance ratio is calculated by integrating over the lens radius to give: d R = ∫ 0 R 1 − tanh 0.5 * | P r − Rx _ sphere | rdr ∫ 0 R rdr wherein the monocular weighted near ratio is calculated by integrating over the lens radius to give: n R = ∫ 0 R 1 − tanh 0.5 * | P r − Rx _ sphere − Rx _ add | rdr ∫ 0 R rdr Δ d is a mean value for a disparity at distance vision between the first and second lens for pupil diameters of about 2.5 to 6mm; Δ n is a mean value for a disparity at near vision between the first and second lens for pupil diameters of about 3.5 to about 6 mm; Rx_sphere is the sphere prescription power in diopters for the eye; Rx_add is an additional power in diopters added to a distance prescription to provide near vision correction for an individual; R is the radius of the pupil; wherein P(r) is the power of the lens plus eye given by P(r) = P CL (r) + SA eye * r 2 + F; P CL (r) is the power profile of the contact lens; SA eye is the spherical aberration of the eye; r is the radial distance from the centre of lens; and F is the lens fit.