Multifocal ophthalmic lens having chromatic aberration correction

An ophthalmic lens, comprising

• an optic comprising an anterior surface, a posterior surface, and an optical axis, at least one of the anterior surface and the posterior surface having a surface profile including:
• a base curvature;
• a refractive region having the base curvature;
• a diffractive region comprising a diffractive profile comprising plurality of diffractive steps, at least a portion of the diffractive profile being a combination of:
• a base diffractive profile defining multiple foci for the ophthalmic lens;
• an achromatizing structure that reduces longitudinal chromatic aberrations;
• and
• the surface profile is defined as follows:
• Sagachromatized_multifocal=Sag(r)+g(r);
• Sag(r)=Zbase(r) 0≤r≤r1;
• Sag(r)=Zbase(r)+Fdiffractive(r,T)+Δ′1 r1<r≤r1′;
• Sag(r)=Z′base(r)+Fdiffractive(r,T)+Δ1″ r1′<r≤r2′;
• Sag(r)=Zbase(r)+Fdiffractive(r,T)+Δ1′″ r2′<r≤r2;
• Sag(r)=Zbase(r)+Δ2′ r2<r≤r3;
• g
• ⁡
• (
• r
• )
• =
• 0
• 0
• ≤
• r
• ≤
• r
• 1
• ′
• ;
• g
• ⁡
• (
• r
• )
• =
• h
• ×
• (
• r
• 2
• T
• g
• -
• ⌊
• r
• 2
• T
• g
• ⌋
• )
• r
• 1
• ′
• <
• r
• ≤
• r
• 2
• ′
• ;
• g
• ⁡
• (
• r
• )
• =
• 0
• r
• 2
• ′
• <
• r
• ≤
• r
• 3
• ;
• wherein:
• Sag(r) defines the surface profile of the ophthalmic lens excluding the achromatizing structure;
• g(r) defines the achromatizing structure;
• r denotes a radial distance from the optical axis;
• Zbase(r) denotes the base curvature;
• Z′base(r) denotes a modified base curvature that takes into account a focus shift caused by the achromatizing structure;
• Fdiffractive defines the base diffractive structure;
• T denotes the period in r2 space for the base diffractive structure;
• r1, r2, r3, r1′ and r2′ denote junction points on the surface profile;
• and
• Δ1′, Δ1″, Δ1′″, and Δ2′ are constants;
• Tg denotes a period in r2 space of the achromatizing structure;
• └ ┘ denotes a floor function, wherein └x┘=max{m∈z|m≤x} is a set of integers;
• and
• h denotes a step height.