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US 12,109,107 B2Granted
Multifocal ophthalmic lens having chromatic aberration correction
AssigneeAlcon Inc.
InventorsXin Hong, Xin Wei
Life of this patent
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Abstract
An ophthalmic lens includes an optic comprising an anterior surface, a posterior surface, and an optical axis. At least one of the anterior surface and the posterior surface has a surface profile including a base curvature, a refractive region having the base curvature, and a diffractive region comprising a diffractive profile including a plurality of diffractive steps. At least a portion of the diffractive profile constitutes a combination of a base diffractive profile defining multiple foci for the ophthalmic lens and an achromatizing structure that reduces longitudinal chromatic aberrations.
Claims6
An ophthalmic lens, comprising:
- an optic comprising a surface profile including a base curvature and a diffractive profile comprising a 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;
- and
- an achromatizing structure that reduces longitudinal chromatic aberrations;
- and
- the surface profile is defined as follows:
- Sag
- achromatized_multifocal
- =
- Sag
-
- (
- r
- )
- +
- g
-
- (
- r
- )
- ;
- 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;
- r3, r1′ and r2′ denote junction points on the surface profile;
- 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.
88 more elements
Dependencies are inferred from the claim text.