Pseudo-accommodative IOL having diffractive zones with varying areas

• US 7,441,894 B2
• Filed: 02/09/2006
• Issued: 10/28/2008
• Est. Priority Date: 02/09/2006
• Status: Active Grant

• Current Assignee: Alcon Incorporated
• Original Assignee: Alcon Manufacturing Limited (Alcon Incorporated)
• Inventors: Zhang, Xiaoxiao, Hong, Xin, VanNoy, Steve
• Primary Examiner(s): Collins; Darryl J
• Application Number:
  US11/350,497
• Publication Number:
  US 20070182921A1
• Time in Patent Office: 992 Days
• Field of Search: 351/161, 351/164, 351/168, 623/6.24, 623/6.27, 623/6.3, 623/6.31
• US Class Current: 351/168
• CPC Class Codes: A61F 2/1618 Multifocal lenses
• CPC Class Codes: A61F 2/1654 Diffractive lenses
• CPC Class Codes: A61F 2002/1699 Additional features not otherwise provided for
• CPC Class Codes: A61F 2250/0014 having different values of a given property or geometrical feature, e.g. mechanical property or material property, at different locations within the same prosthesis
• CPC Class Codes: G02C 2202/20 Diffractive and Fresnel lenses or lens portions

Abstract

In one aspect of the invention, a trifocal ophthalmic lens is disclosed that includes an optic having at least one optical surface, and a plurality of diffractive zones that are disposed on a portion of that surface about an optical axis of the optic. At least two of those diffractive zones have different areas so as to cause broadening of optical energy profiles at a near and a far foci of the diffractive zones for generating an intermediate focus.

Claims

1. A multifocal ophthalmic lens, comprising;

an optic having at least one optical surface; and

a plurality of diffractive zones disposed about an optical axis of the optic, at least two of said diffractive zones having different areas so as to cause broadening of optical energy profiles at a near and a far foci of said diffractive zones for generating an intermediate focus, wherein the diffractive zones comprise annular zones characterized by a radius (r_i) from the optical axis, wherein a square of the radius of a zone is defined by the following relation;

r_i²=(2i+1)λ

ƒ

+g(i),

wherein i denotes a zone number, r_i² denotes a square radius of that zone, ƒ

denotes an add power of the near focus relative to the far focus, λ

denotes a design wavelength, and g(i) denotes a non-constant function of i.

2. The multifocal lens of claim 1, wherein g(i) is defined by the following relation:

g(i)=(ai²+bi)ƒ

,

wherein

i denotes the zone number,

a and b are two adjustable parameters, and

ƒ

denotes the focal length of the near focus.

3. The multifocal lens of claim 2, wherein said adjustable parameter a is in a range of about 0.1 λ

to about 0.3 λ

.

4. The multifocal lens of claim 3, wherein said adjustable parameter b is in a range of about 1.5 λ

to about 2.5 λ

.