Prismatic contact lens

Abstract

A class of prismatic contact lenses includes a first prism zone, having a first prism and a first optical power; and a progressive prism zone, adjacent to the first prism zone, having a progressive prism that varies from the first prism to a second prism. The prismatic contact lens can further comprise a second prism zone, adjacent to the progressive prism zone, having the second prism and a second optical power. Another class of prismatic contact lenses include a first prism zone, having a first prism and a first optical power; a second prism zone, adjacent to the first prism zone, having a second prism and a second optical power; and a sharp transition between the first prism zone and the second prism zone.

1 . A prismatic contact lens, comprising:
 a first prism zone, having a first prism and a first optical power; and   a progressive prism zone, adjacent to the first prism zone, having a progressive prism that varies from the first prism to a second prism.   
     
     
         2 . The prismatic contact lens of  claim 1 , wherein:
 a prismatic power of the progressive prism varies progressively at least one of   in a radial direction, with an increasing radius, along an x-axis, along a y-axis, and along a tilted meridian, making an angle with the x-axis and the y-axis.   
     
     
         3 . The prismatic contact lens of  claim 1 , wherein:
 a refraction direction of the progressive prism varies progressively at least one of   in a radial direction, with an increasing radius, along an x-axis, along a y-axis, and along a tilted meridian, making an angle with the x-axis and the y-axis.   
     
     
         4 . The prismatic contact lens of  claim 1 , comprising:
 a second prism zone, adjacent to the progressive prism zone, having the second prism and a second optical power.   
     
     
         5 . The prismatic contact lens of  claim 4 , wherein:
 the first optical power is consistent with distance vision; and   the second optical power is consistent with near vision.   
     
     
         6 . The prismatic contact lens of  claim 4 , wherein:
 a difference between the first optical power and the second optical power is less than 0.5 D.   
     
     
         7 . The prismatic contact lens of  claim 4 , wherein:
 at least one of a prism refraction direction of the first prism, a prism refraction direction of the progressive prism, and a prism refraction direction of the second prism is tilted relative to a horizontal x-axis.   
     
     
         8 . The prismatic contact lens of  claim 1 , wherein:
 the first prism zone is a central circular region; and   the progressive prism zone includes a ring around the central circular region.   
     
     
         9 . The prismatic contact lens of  claim 8 , comprising:
 a second prism zone, including at least one of a ring and an annulus around the progressive prism zone.   
     
     
         10 . The prismatic contact lens of  claim 1 , wherein:
 the first prism zone includes an upper region of the prismatic contact lens; and   the progressive prism zone includes a lower region of the prismatic contact lens.   
     
     
         11 . The prismatic contact lens of  claim 1 , comprising:
 a second prism zone, wherein   the first prism zone includes an upper region of the prismatic contact lens;   the progressive prism zone includes a middle region of the prismatic contact lens; and   the second prism zone includes a lower region of the prismatic contact lens.   
     
     
         12 . The prismatic contact lens of  claim 1 , wherein:
 the prismatic contact lens is a multi-zone lens, including
 first prism zones, including the first prism zone, having the first prism and the first optical power, 
 progressive prism zones, including the progressive prism zone, having a progressive prism that varies from the first prism to a second prism; and 
 second prism zones, having the second prism and a second optical power. 
   
     
     
         13 . The prismatic contact lens of  claim 12 , wherein:
 the first prism zones include a central region and first prism rings;   the progressive prism zones include progressive prism rings; and   the second prism zones include second prism rings.   
     
     
         14 . The prismatic contact lens of  claim 12 , wherein:
 the first prism zones include radial first prism zone segments;   the progressive prism zones include radial progressive prism zone segments; and   the second prism zones include radial second prism zone segments.   
     
     
         15 . The prismatic contact lens of  claim 12 , wherein:
 the first prism zones include horizontal first prism zone strips;   the progressive prism zones include horizontal progressive prism zone strips; and   the second prism zones include horizontal second prism zone strips.   
     
     
         16 . The prismatic contact lens of  claim 1 , wherein:
 the progressive prism zone is asymmetrically off-center.   
     
     
         17 . The prismatic contact lens of  claim 1 , comprising:
 at least one of a peripheral tapered edge, a ballast in a lower region of the prismatic contact lens, and an orientation mark.   
     
     
         18 . The prismatic contact lens of  claim 1 , wherein:
 at least one of the first prism zone and the progressive prism zone is toric.   
     
     
         19 . A prismatic contact lens, comprising:
 a first prism zone, having a first prism and a first optical power; and   a second prism zone, adjacent to the first prism zone, having a second prism and a second optical power; and   a sharp transition between the first prism zone and the second prism zone.   
     
     
         20 . The prismatic contact lens of  claim 19 , wherein:
 at least one of a refraction direction of the first prism and a refraction direction of the second prism is different from horizontal.   
     
     
         21 . The prismatic contact lens of  claim 19 , wherein:
 the first optical power is consistent with distance vision; and   the second optical power is consistent with near vision.   
     
     
         22 . The prismatic contact lens of  claim 19 , wherein:
 the first prism zone is a central circular region; and   the second prism zone, including one of a ring and an annulus, around the central circular region.   
     
     
         23 . The prismatic contact lens of  claim 22 , wherein:
 a prismatic power of the first prism is approximately zero; and   a prismatic power of the second prism is non-zero.   
     
     
         24 . The prismatic contact lens of  claim 19 , wherein:
 the first prism zone includes an upper region of the prismatic contact lens; and   the second prism zone includes a lower region of the prismatic contact lens.   
     
     
         25 . The prismatic contact lens of  claim 19 , wherein:
 the prismatic contact lens is a multi-zone lens, including
 first prism zones, including the first prism zone, having the first prism and the first optical power; 
 second prism zones, having the second prism and the second optical power; and 
   sharp transitions, between the first prism zones from the second prism zones.   
     
     
         26 . The prismatic contact lens of  claim 25 , wherein:
 the first prism zones include a central region and first prism rings; and   the second prism zones include second prism rings.   
     
     
         27 . The prismatic contact lens of  claim 25 , wherein:
 the first prism zones include radial first prism zone segments; and   the second prism zones include radial second prism zone segments.   
     
     
         28 . The prismatic contact lens of  claim 25 , wherein:
 the first prism zones include horizontal first prism zone strips; and   the second prism zones include horizontal second prism zone strips.   
     
     
         29 . The prismatic contact lens of  claim 19 , wherein:
 at least one of the first prism zone and the second prism zone is toric.   
     
     
         30 . A method of making a prismatic contact lens, the method comprising the steps of:
 providing an injection mold, with a negative shape of a prismatic contact lens with a first prism zone, having a first prism and a first optical power; and a progressive prism zone, adjacent to the first prism zone, having a progressive prism that varies from the first prism to a second prism;   heating a soft contact lens material to a molten contact lens material;   injecting the molten contact lens material into the injection mold to create a molded contact lens;   cooling the molded contact lens by cooling the injection mold; and   removing the cooled, molded contact lens from the injection mold.   
     
     
         31 . The method of  claim 30 , the providing step further comprising:
 providing the injection mold with the negative shape of the prismatic contact lens having a second prism zone, adjacent to the progressive prism zone, having the second prism and a second optical power.