Contact lenses

Abstract

A contact lens having a rotational stabilization mechanism thereon, such as prism ballast, and a thickness profile that reduces the torque imparted on the lens by the action of the eyelids, especially for stabilizing toric lenses. The prism ballast is provided on one or more portions of the anterior face of the lens such that the lens body has a uniform thickness of within 10% along horizontal cross-sections. The anterior face of the lens may be segregated into a peripheral zone, an inner zone circumscribed by the peripheral zone, and a central optic zone. The prism ballast portion is provided within the inner zone, which may be further subdivided into a superior portion, an intermediate portion proximate the optic zone, and an inferior portion. The ballast portion increases in thickness along a superior-inferior line parallel to a vertical meridian, and has a substantially uniform thickness perpendicular thereto. The peripheral zone may be tapered, and have a rounded edge. The rate of thickness change across any portion of the peripheral zone is less than about 250 μm/mm.

1 . A contact lens, comprising: 
 an anterior surface, a posterior surface, a peripheral edge, and a thickness defined as a distance between the anterior surface and the posterior surface;    a toric optic zone;    a second zone circumscribing the toric optic zone, the second zone comprising a region of maximum thickness along a 225 degree meridian of the contact lens,    wherein along the 225 degree meridian, the distance between the region of maximum thickness and the peripheral edge is less than about 1.4 mm.    
   
   
       2 . The contact lens of  claim 1  which is a fully molded contact lens.  
   
   
       3 . The contact lens of  claim 1  which is a soft contact lens.  
   
   
       4 . The contact lens of  claim 3 , further comprising a hydrophilic material.  
   
   
       5 . The contact lens of  claim 3  which is made from a hydroxyethylmethacrylate.  
   
   
       6 . The contact lens of  claim 1  which is a silicone hydrogel contact lens.  
   
   
       7 . The contact lens of  claim 6 , wherein the peripheral edge comprises a rounded edge surface.  
   
   
       8 . The contact lens of  claim 1  which is a rotationally stabilized contact lens.  
   
   
       9 . The contact lens of  claim 8  which is a contact lens selected from the group consisting of prism ballasted contact lenses, periballasted contact lenses, and dynamically stabilized contact lenses.  
   
   
       10 . The contact lens of  claim 8 , wherein the second zone further comprises a midsection of the contact lens having a greater thickness relative to a superior section and an inferior section of the second zone.  
   
   
       11 . The contact lens of  claim 1 , wherein the second zone further comprises a second region of maximum thickness along a 270 degree meridian, and along the 270 degree meridian, the distance between the second region of maximum thickness and the peripheral edge is less than about 2.1 mm.  
   
   
       12 . The contact lens of  claim 1 , wherein the second zone further comprises a second region of maximum thickness along a 180 degree meridian, and along the 180 degree meridian, the distance between the second region of maximum thickness and the peripheral edge is less than about 1.3 mm.  
   
   
       13 . The contact lens of  claim 1 , wherein the second zone further comprises a second region of maximum thickness along a 270 degree meridian, and a third region of maximum thickness along a 180 degree meridian, and along the 270 degree meridian, the distance between the second region of maximum thickness and the peripheral edge is less than about 2.1 mm, and along the 180 degree meridian, the distance between the third region of maximum thickness and the peripheral edge is less than about 1.3 mm.  
   
   
       14 . The contact lens of  claim 1 , wherein the second zone comprises at least one region having a substantially uniform horizontal thickness.  
   
   
       15 . The contact lens of  claim 1 , wherein, along the 225 degree meridian, a rate of change of thickness from the region of maximum thickness to the peripheral edge is less than about 250 μm/mm.  
   
   
       16 . The contact lens of  claim 15 , wherein, along the 225 degree meridian, a rate of change of thickness from the region of maximum thickness to the peripheral edge is less than about 200 μm/mm.  
   
   
       17 . The contact lens of  claim 1 , wherein the maximum thickness along the 225 degree meridian of the lens is between about 200-400 μm.  
   
   
       18 . The contact lens of  claim 17 , wherein the maximum thickness along the 225 degree meridian of the lens is between about 250-350 μm.  
   
   
       19 . A contact lens, comprising: 
 a silicone hydrogel lens body comprising an anterior surface, a posterior surface, a peripheral edge, and a thickness defined as a distance between the anterior surface and the posterior surface;    a toric optic zone;    a second zone circumscribing the toric optic zone, the second zone comprising a region of maximum thickness along a 180 degree meridian of the contact lens,    wherein along the 180 degree meridian, the distance between the region of maximum thickness and the peripheral edge is less than about 1.3 mm.    
   
   
       20 . The contact lens of  claim 19  which is a fully molded contact lens.  
   
   
       21 . The contact lens of  claim 19 , wherein the peripheral edge comprises a rounded edge surface.  
   
   
       22 . The contact lens of  claim 19  which is a rotationally stabilized contact lens.  
   
   
       23 . The contact lens of  claim 22  which is a contact lens selected from the group consisting of prism ballasted contact lenses, periballasted contact lenses, and dynamically stabilized contact lenses.  
   
   
       24 . The contact lens of  claim 22 , wherein the second zone further comprises a midsection of the contact lens having a greater thickness relative to a superior section and an inferior section of the second zone.  
   
   
       25 . The contact lens of  claim 19 , wherein the second zone further comprises a second region of maximum thickness along a 270 degree meridian, and along the 270 degree meridian, the distance between the second region of maximum thickness and the peripheral edge is less than about 2.1 mm.  
   
   
       26 . The contact lens of  claim 19 , wherein the second zone further comprises a second region of maximum thickness along a 225 degree meridian, and along the 225 degree meridian, the distance between the second region of maximum thickness and the peripheral edge is less than about 1.8 mm.  
   
   
       27 . The contact lens of  claim 19 , wherein the second zone comprises at least one region having a substantially uniform horizontal thickness.  
   
   
       28 . The contact lens of  claim 19 , wherein, along any meridian, a rate of change of thickness from the region of maximum thickness to the peripheral edge is less than about 250 μm/mm.  
   
   
       29 . The contact lens of  claim 28 , wherein the rate of change of thickness is less than about 200 μm/mm.  
   
   
       30 . A contact lens, comprising: 
 a rotationally stabilized silicone-hydrogel contact lens body comprising a centrally located optic zone surrounding an optical axis of the lens body, and an optic circumscribing zone comprising at least one region having a substantially uniform horizontal thickness effective in rotationally stabilizing the lens body about the optical axis of the lens body when placed on an eye of an individual.    
   
   
       31 . The contact lens of  claim 30 , wherein the lens body further comprises a ballast.  
   
   
       32 . The contact lens of  claim 30 , wherein the lens body includes a midsection having a greater thickness relative to a superior section and an inferior section of the lens body.  
   
   
       33 . The contact lens of  claim 30 , wherein the lens body has a maximum thickness at a region located between the optic zone and an inferior edge of the lens body.  
   
   
       34 . The contact lens of  claim 30 , wherein the lens body is non-axisymmetric.  
   
   
       35 . The contact lens of  claim 30  which is a toric contact lens.  
   
   
       36 . The contact lens of  claim 30 , wherein, along a 225° meridian, the distance between the optic circumscribing zone and the peripheral edge is less than about 1.8 mm.  
   
   
       37 . A contact lens, comprising: 
 a non-axisymmetric lens body comprising an anterior surface; a posterior surface; a peripheral edge; an optic zone; and a ballast having a ballast periphery,    wherein along a 225 degree meridian of the lens body, the distance between the ballast periphery and the peripheral edge is less than about 1.4 mm.    
   
   
       38 . The contact lens of  claim 37  which is a fully molded contact lens.  
   
   
       39 . The contact lens of  claim 37  which is a soft contact lens.  
   
   
       40 . The contact lens of  claim 39 , further comprising a hydrophilic material.  
   
   
       41 . The contact lens of  claim 39  which is made from a hydroxyethylmethacrylate.  
   
   
       42 . The contact lens of  claim 37  which is a silicone hydrogel contact lens.  
   
   
       43 . The contact lens of  claim 42 , wherein the peripheral edge comprises a rounded edge surface.  
   
   
       44 . The contact lens of  claim 37  which is a contact lens selected from the group consisting of prism ballasted contact lenses, periballasted contact lenses, and dynamically stabilized contact lenses.  
   
   
       45 . The contact lens of  claim 37 , wherein, along a 270 degree meridian of the lens body, the distance between the ballast periphery and the peripheral edge is less than about 2.1 mm.  
   
   
       46 . The contact lens of  claim 37 , wherein, along a 180 degree meridian of the lens body, the distance between the ballast periphery and the peripheral edge is less than about 1.3 mm.  
   
   
       47 . The contact lens of  claim 37 , wherein the lens body further comprises a second zone circumscribing the optic zone and comprising at least one region having a substantially uniform horizontal thickness.  
   
   
       48 . The contact lens of  claim 37 , wherein, along the 225 degree meridian, a rate of change of thickness from the ballast periphery to the peripheral edge is less than about 250 μm/mm.  
   
   
       49 . The contact lens of  claim 48 , wherein the rate of change of thickness is less than about 200 μm/mm.  
   
   
       50 . The contact lens of  claim 37 , wherein the maximum thickness along the 225 degree meridian of the lens body is between about 200-400 μm.  
   
   
       51 . The contact lens of  claim 50 , wherein the maximum thickness along the 225 degree meridian of the lens body is between about 250-350 μm.  
   
   
       52 . A contact lens, comprising: 
 a non-axisymmetric silicone hydrogel lens body comprising an anterior surface; a posterior surface; a peripheral edge; an optic zone; and a ballast having a ballast periphery,    wherein along the 180 degree meridian, the distance between the ballast periphery the peripheral edge is less than about 1.3 mm.    
   
   
       53 . The contact lens of  claim 52  which is a fully molded contact lens.  
   
   
       54 . The contact lens of  claim 52 , wherein the peripheral edge comprises a rounded edge surface.  
   
   
       55 . The contact lens of  claim 52  which is a contact lens selected from the group consisting of prism ballasted contact lenses, periballasted contact lenses, and dynamically stabilized contact lenses.  
   
   
       56 . The contact lens of  claim 52 , wherein along a 270 degree meridian of the lens body, the distance between the ballast periphery and the peripheral edge is less than about 2.1 mm.  
   
   
       57 . The contact lens of  claim 52 , wherein along a 225 degree meridian of the lens body, the distance between the ballast periphery and the peripheral edge is less than about 1.8 mm.  
   
   
       58 . The contact lens of  claim 52 , wherein the lens body further comprises a second zone circumscribing the optic zone and comprising at least one region having a substantially uniform horizontal thickness.  
   
   
       59 . The contact lens of  claim 52 , wherein, along any meridian, a rate of change of thickness from the ballast periphery to the peripheral edge is less than about 250 μm/mm.  
   
   
       60 . The contact lens of  claim 59 , wherein the rate of change of thickness is less than about 200 μm/mm.