Multifocal diffractive ophthalmic lenses with evenly spaced echelettes

Patent metadata

Field	Value
Publication number	US-2022382075-A1
Application number	US-202217804119-A
Country	US
Kind code	A1
Filing date	May 26, 2022
Priority date	May 28, 2021
Publication date	Dec 1, 2022
Grant date	—

Abstract

Certain embodiments described herein are directed to a multifocal ophthalmic lens including a base lens having a base curvature corresponding to a base power, and a diffractive structure comprising a central zone and a plurality of annular echelettes formed on a first surface of the base lens. A radial spacing of each of the plurality of annular echelettes is constant throughout the diffractive structure.

First claim

1 . A multifocal ophthalmic lens, comprising:
a base lens having a base curvature corresponding to a base power; and a diffractive structure comprising a central zone and a plurality of annular echelettes formed on a first surface of the base lens, wherein a radial spacing of each of the plurality of annular echelettes is constant throughout the diffractive structure.

2 . The multifocal ophthalmic lens of claim 1 , wherein:
the first surface is an anterior surface of the multifocal ophthalmic lens.

3 . The multifocal ophthalmic lens of claim 1 , wherein:
the first surface is a posterior surface of the multifocal ophthalmic lens.

4 . The multifocal ophthalmic lens of claim 1 , wherein:
the constant radial spacing of the each of the plurality of annular echelettes is between 1/60 and 1/20 of a diameter of the base lens.

5 . The multifocal ophthalmic lens of claim 1 , wherein:
a sag of each of the central zone and the plurality of annular echelettes is between −1.0 and 1.0 in a unit of a design wavelength.

6 . The multifocal ophthalmic lens of claim 5 , wherein:
a phase delay of each of the central zone and the plurality of annular echelettes is between −1.0 and 1.0 in the unit of the design wavelength.

7 . The multifocal ophthalmic lens of claim 1 , wherein:
a sag of each of the central zone and the plurality of annular echelettes from the first surface of the base lens varies from an inner radius to an outer radius thereof polynomially with respect to a radial distance r from the inner radius.

8 . The multifocal ophthalmic lens of claim 1 , wherein:
a sag of the j-th echelette (j=1, 2, 3, . . . ) from the first surface of the base lens varies from an inner radius r j-1 to an outer radius r j polynomially with respect to a radial distance r from the inner radius r j-1 as

h
j

=

a
j

(

r
j

-

r

j
-
1

)

⁢

(

r

z
j

-

r

j
-
1

)

+

φ
j

,

z
j

 being a positive number greater than or equal to 1 (z j ≥1), or

h
j

=

-

a
j

(

r
j

-

r

j
-
1

)

⁢

(

r

z
j

+

r

j
-
1

)

+

φ
j

,

z
j

 being a negative number (z j <0), wherein:
the first echelette is the central zone,
the plurality of annular echelettes are j-th echelettes (j=2, 3, . . . ),
a j is a step height of the j-th echelette, and
φ j corresponds to a phase delay of the j-th echelette.

9 . The multifocal ophthalmic lens of claim 1 , wherein:
an area of the diffractive structure is between 40% and 100% of a surface area of the first surface of the base lens.

10 . A multifocal ophthalmic lens, comprising:
a base lens having a base curvature corresponding to a base power; and a diffractive structure formed on a first surface of the base lens generating a zero-order diffraction having a distance vision focal point determined by the base power, a first-order diffraction, a second-order diffraction having an intermediate vision focal point, and a third-order diffraction corresponding to a near vision focal point, wherein: diffraction efficiency of the zero-order diffraction is between 35% and 50%, diffraction efficiency of the first-order diffraction is between 3% and 10%, diffraction efficiency of the second-order diffraction is between 10% and 15%, and diffraction efficiency of the third-order diffraction is between 15% and 25%.

11 . The multifocal ophthalmic lens of claim 10 , wherein:
the first surface is an anterior surface of the multifocal ophthalmic lens, or a posterior surface of the multifocal ophthalmic lens.

12 . The multifocal ophthalmic lens of claim 10 , wherein:
the diffractive structure comprises a central zone and a plurality of annular echelettes formed on a first surface of the base lens, and the constant radial spacing of each of the plurality of annular echelettes is between 1/60 and 1/20 of a diameter of the base lens.

13 . The multifocal ophthalmic lens of claim 12 , wherein:
a sag of each of the central zone and the plurality of annular echelettes is between −1.0 and 1.0 in a unit of a design wavelength, and a phase delay of each of the central zone and the plurali

Assignees

• Alcon Inc

Inventors

• Bordbar Behzad
• Das Kamal K

Classifications

• G02C2202/20

  Diffractive and Fresnel lenses or lens portions · CPC title

• G02C7/044 Primary

  Annular configuration, e.g. pupil tuned · CPC title

• G02C7/041 Primary

  bifocal; multifocal · CPC title