Contact lens for correcting myopia and/or astigmatism

Abstract

The present invention provides a myopia and/or astigmatism-correcting contact lens for correcting myopia and/or astigmatism based on the alteration in the shape of a patient's cornea. The myopia and/or astigmatism-correcting contact lens comprises a pressure zone having a first surface defined by the inner surface of the contact lens located on the side of the patient's cornea and positioned at the center of the contact lens. The first surface is formed in a concave shape having a curvature less than that of the central surface of the patient's cornea. The contact lens further includes a relief zone having a concave-shaped second surface defined by the inner surface of the contact lens located on the side of the patient's cornea and positioned at the periphery of the pressure zone, and an anchor zone having a concave-shaped third surface defined by the inner surface of the contact lens on the side of the patient's cornea and positioned at the periphery of the relief zone. The first surface has a curvature determined based on the shape of the patient's cornea to induce a specific desired alteration in the shape of the patient's cornea. Further, each of the curvatures of the first, second and third surfaces is arranged to satisfy the following formulas, RC=BC+ 7.0˜9.0 D ( diopter ), and AC=BC+ 2.0˜4.0 D where BC is the curvature of the first surface, RC is the curvature of the second surface, and AC is the curvature of the third surface.

What is claimed is:  
     
         1 . A myopia and/or astigmatism-correcting contact lens for correcting myopia and/or astigmatism based on the alteration in the shape of a patient's cornea, said myopia and/or astigmatism-correcting contact lens comprising; 
 a pressure zone having a first surface defined by the inner surface of said contact lens located on the side of the patient's cornea and positioned at the center of said contact lens, said first surface being formed in a concave shape having a curvature less than that of the central surface of the patient's cornea;    a relief zone having a second surface defined by the inner surface of said contact lens located on the side of the patient's cornea and positioned at the periphery of said pressure zone, said second surface being formed in a concave shape; and    an anchor zone having a third surface defined by the inner surface of said contact lens on the side of the patient's cornea and positioned at the periphery of said relief zone, said third surface being formed in a concave shape,wherein    said first surface has a curvature determined based on the shape of the patient's cornea to induce a specific desired alteration in the shape of the patient's cornea, and    each of the curvatures of said first, second and third surfaces is arranged to satisfy the following formulas,     RC=BC+ 7.0˜9.0  D  ( diopter ),  and   AC=BC+ 2.0˜4.0  D     where BC is the curvature of the first surface, RC is the curvature of the second surface, and AC is the curvature of the third surface.    
     
     
         2 . A myopia and/or astigmatism-correcting contact lens as defined in  claim 1 , wherein each of the curvatures of said first, second and third surfaces is arranged to satisfy the following formulas, 
         RC=BC+ 7.5˜8.5  D, and   AC=BC+ 2.5˜3.5  D   
     
     
         3 . A myopia and/or astigmatism-correcting contact lens as defined in  claim 1 , wherein each of the curvatures of said first, second and third surfaces is arranged to satisfy the following formulas, 
         RC=BC+about  8.0  D, and   AC=BC+about  3.0  D   
     
     
         4 . A myopia and/or astigmatism-correcting contact lens as defined in either one of  claim 1 , which has a diameter ranging from about 9.0 to about 11.0 mm.  
     
     
         5 . A myopia and/or astigmatism-correcting contact lens as defined in either one of  claim 1 , which has a diameter ranging from about 9.5 to about 10.5 mm.  
     
     
         6 . A myopia and/or astigmatism-correcting contact lens as defined in either one of  claim 1 , which has a diameter of about 10 mm.  
     
     
         7 . A myopia and/or astigmatism-correcting contact lens for correcting myopia and/or astigmatism based on the alteration in the shape of a patient's cornea, said myopia and/or astigmatism-correcting contact lens comprising; 
 a pressure zone having a first surface defined by the inner surface of said contact lens located on the side of a patient's cornea and positioned at the center of said contact lens, said first surface being formed in a concave shape having a curvature less than that of the central surface of the patient's cornea;    a relief zone having a second surface defined by the inner surface of said contact lens located on the side of the patient's cornea and positioned at the periphery of said pressure zone, said second surface being formed in a concave shape;    a first anchor zone having a third surface defined by the inner surface of said contact lens on the side of the patient's cornea and positioned at the periphery of said relief zone, said third surface being formed in a concave shape; and    a second anchor zone having a fourth surface defined by the inner surface of said contact lens on the side of the patient's cornea and positioned at the periphery of said first anchor zone, said fourth surface being formed in a concave shape, wherein    said first surface has a curvature determined based on the shape of the patient's cornea to induce a specific desired alteration in the shape of the patient's cornea, and    each of the curvatures of said first, second, third and fourth surfaces is arranged to satisfy the following formulas,     RC=BC+ 11.00-13.0  D   AC  1 =BC+ 3.0-5.0  D, and   AC  2 =BC+ 4.0-6.0  D      where BC is the curvature of the first surface, RC is the curvature of the second surface, AC  1  is the curvature of the third surface, and AC  2  is the curvature of the fourth surface.    
     
     
         8 . A myopia and/or astigmatism-correcting contact lens as defined in  claim 7 , wherein each of the curvatures of said first, second, third and fourth surfaces is arranged to satisfy the following formulas, 
         RC=BC+ 11.5-12.5  D,   AC  1 =BC+ 3.5-4.5  D and   AC  2 =BC+ 4.5-5.5  D   
     
     
         9 . A myopia and/or astigmatism-correcting contact lens as defined in  claim 7 , wherein each of the curvatures of said first, second, third and fourth surfaces is arranged to satisfy the following formulas, 
         RC=BC+about  12  D,   AC  1 =BC+about  4  D, and   AC  2 =BC+about  5  D   
     
     
         10 . A myopia and/or astigmatism-correcting contact lens as defined in  claim 7 , which has a diameter ranging from about 9.6 to about 11.6 mm.  
     
     
         11 . A myopia and/or astigmatism-correcting contact lens as defined in  claim 7 , which has a diameter ranging from about 10.1 to about 11.6 mm.  
     
     
         12 . A myopia and/or astigmatism-correcting contact lens as defined in  claim 7 , which has a diameter ranging from about 10.6 to about 11.2 mm.  
     
     
         13 . A myopia and/or astigmatism-correcting contact lens as defined in  claim 7 , which has a diameter of either one of about 10.2, 10.4, 10.6, 10.8, and 11.0 mm.  
     
     
         14 . A myopia and/or astigmatism-correcting contact lens for correcting myopia and/or astigmatism based on the alteration in the shape of a patient's cornea, said myopia and/or astigmatism-correcting contact lens comprising; 
 a pressure zone having a first surface defined by the inner surface of said contact lens located on the side of a patient's cornea and positioned at the center of said contact lens, said first surface being formed in a concave shape having a curvature less than that of the central surface of the patient's cornea;    a relief zone having a second surface defined by the inner surface of said contact lens located on the side of the patient's cornea and positioned at the periphery of said pressure zone, said second surface being formed in a concave shape;    a first anchor zone having a third surface defined by the inner surface of said contact lens on the side of the patient's cornea and positioned at the periphery of said relief zone, said third surface being formed in a concave shape; and    a second anchor zone having a fourth surface defined by the inner surface of said contact lens on the side of the patient's cornea and positioned at the periphery of said first anchor zone, said fourth surface being formed in a concave shape, wherein    said first surface has a curvature determined based on the shape of the patient's cornea to induce a specific desired alteration in the shape of the patient's cornea, and    each of the curvatures of said first, second, third and fourth surfaces is arranged to satisfy the following formulas,     RC=BC+ 12.5-14.5  D,   AC  1 =BC+ 3.0-5.0  D, and   AC  2= BC+ 4.0-6.0  D      where BC is the curvature of the first surface, RC is the curvature of the second surface, AC  1  is the curvature of the third surface, and AC  2  is the curvature of the fourth surface.    
     
     
         15 . A myopia and/or astigmatism-correcting contact lens as defined in  claim 14 , wherein each of the curvatures of said first, second, third and fourth surfaces is arranged to satisfy the following formulas, 
         RC=BC+ 13.0-14.0  D,   AC  1 =BC+ 3.5-4.5  D, and   AC  2 =BC+ 4.5-5.5  D   
     
     
         16 . A myopia and/or astigmatism-correcting contact lens as defined in  claim 14 , wherein each of the curvatures of said first, second, third and fourth surfaces is arranged to satisfy the following formulas, 
         RC=BC+about  13.5  D,   AC  1 =BC+about  4  D, and   AC  2 =BC+about  5  D   
     
     
         17 . A myopia and/or astigmatism-correcting contact lens as defined in  claim 14 , which has a diameter ranging from about 9.6 to about 11.6 mm.  
     
     
         18 . A myopia and/or astigmatism-correcting contact lens as defined in  claim 14 , which has a diameter ranging from about 10.1 to about 11.6 mm.  
     
     
         19 . A myopia and/or astigmatism-correcting contact lens as defined in  claim 14 , which has a diameter ranging from about 10.6 to about 11.2 mm.  
     
     
         20 . A myopia and/or astigmatism-correcting contact lens as defined in  claim 14 , which has a diameter of either one of about 10.2, 10.4, 10.6, 10.8, and 11.0 mm.