Multifocal diffractive ophthalmic lens using suppressed diffractive order
AssigneeAlcon Inc.
InventorsMYOUNG-TAEK CHOI, XIN HONG, YUEAI LIU
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Abstract
A multifocal ophthalmic lens includes an ophthalmic lens and a diffractive element. The ophthalmic lens has a base curvature corresponding to a base power. The diffractive element produces constructive interference in at least four consecutive diffractive orders corresponding a range of vision between near and distance vision. The constructive interference produces a near focus, a distance focus corresponding to the base power of the ophthalmic lens, and an intermediate focus between the near focus and the distance focus. A diffraction efficiency of at least one of the diffractive orders is suppressed to less than ten percent.
Claims18
An intraocular lens, comprising:
- an ophthalmic lens having a base curvature corresponding to a base power;
- and
- a diffractive profile disposed on at least one of the anterior surface and the posterior surface, the diffractive profile comprising a plurality of annular zones configured to produce constructive interference in at least four consecutive diffractive orders corresponding a range of vision;
- wherein:
- the constructive interference produces a near focus, a distance focus corresponding to the base power of the intraocular lens, and an intermediate focus, each corresponding to a different one of the four consecutive diffractive orders;
- and
- a lowest diffractive order of the consecutive diffractive orders corresponds to the distance focus;
- and
- a diffraction efficiency of the lowest diffractive order is greater than a diffraction efficiency of any other of the consecutive diffractive orders.
An intraocular lens, comprising:
- an ophthalmic lens having a base curvature corresponding to a base power;
- and
- a diffractive profile disposed on at least one of the anterior surface and the posterior surface, the diffractive profile comprising a plurality of annular zones configured to produce constructive interference in at least four consecutive diffractive orders corresponding a range of vision;
- wherein:
- the constructive interference produces a near focus, a distance focus corresponding to the base power of the intraocular lens, a near-intermediate focus, and a far-intermediate focus, each corresponding to a different one of the four consecutive diffractive orders;
- the near focus, the near-intermediate focus, and the far-intermediate focus each correspond to a different add power relative to a the base power;
- a first add power corresponding to the far-intermediate focus is less than one half of a third add power corresponding to the near focus;
- and
- a second add power corresponding to the near-intermediate focus is greater than one half of the third add power corresponding to the near focus.
Dependencies are inferred from the claim text.