Multifocal diffractive ophthalmic lens using suppressed diffractive order

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.

What is claimed is: 
     
         1 . 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.   
     
     
         2 . The intraocular lens of  claim 1 , wherein a diffraction efficiency of at least one of the diffractive orders is suppressed to less than ten percent. 
     
     
         3 . The intraocular lens of  claim 2 , wherein at least a portion of the energy associated with the suppressed diffractive order is redistributed to one or more of the near focus, the intermediate focus, and the distance focus. 
     
     
         4 . The intraocular lens of  claim 1 , wherein the four consecutive diffractive orders include a lowest diffractive order, a highest diffractive order, and two intermediate diffractive orders; and
 the at least one suppressed diffractive order is one of the two intermediate diffractive orders.   
     
     
         5 . The intraocular lens of  claim 1 , wherein the four consecutive diffractive orders include at least two of the following diffractive orders: −4, −3, −2, −1, 0, +1, +2 and +3. 
     
     
         6 . The intraocular lens of  claim 1 , wherein the distance focus corresponds to a 0th diffractive order. 
     
     
         7 . The intraocular lens of  claim 1 , wherein the distance focus corresponds to a diffractive order other than the 0th order. 
     
     
         8 . The intraocular lens of  claim 1 , wherein the three-zone diffractive structure includes repeating sets of diffractive steps. 
     
     
         9 . The intraocular lens of  claim 1 , wherein the near focus corresponds to vision at 40 cm, and the intermediate focus corresponds to vision at 60 cm. 
     
     
         10 . 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.   
     
     
         11 . The intraocular lens of  claim 10 , wherein
 the four consecutive diffractive orders include a lowest diffractive order, a highest diffractive order, and two intermediate diffractive orders; and   at least one of the consecutive diffractive orders is suppressed.   
     
     
         12 . The intraocular lens of  claim 11 , wherein
 the four consecutive diffractive orders include a lowest diffractive order, a highest diffractive order, and two intermediate diffractive orders; and   the at least one suppressed diffractive order is one of the two intermediate diffractive orders.   
     
     
         13 . The intraocular lens of  claim 12 , wherein at least a portion of energy associated with the at least one suppressed diffractive order is redistributed to one or more of the near focus, the intermediate focus, and the distance focus. 
     
     
         14 . The intraocular lens of  claim 10 , wherein
 the four consecutive diffractive orders include a lowest diffractive order, a highest diffractive order, and two intermediate diffractive orders; and   a diffraction efficiency of the lowest diffractive order is greater than a diffraction efficiency of any other of the consecutive diffractive orders.   
     
     
         15 . The intraocular lens of  claim 10 , wherein the four consecutive diffractive orders include at least two of the following diffractive orders: −4, −3, −2, −1, 0, +1, +2 and +3. 
     
     
         16 . The intraocular lens of  claim 10 , wherein the distance focus corresponds to a 0th diffractive order. 
     
     
         17 . The intraocular lens of  claim 10 , wherein the distance focus corresponds to a diffractive order other than the 0 th  order. 
     
     
         18 . The intraocular lens of  claim 10 , wherein the plurality of annular zones comprises a plurality of repeating diffractive steps.