Method of designing a spectacle lens

1. A method of designing a spectacle lens having a combined refracting surface in at least one of two refracting surfaces at object and eye sides structuring the spectacle lens, the combined refracting surface having an astigmatism correcting toric surface combined with a progressive refracting surface having a distance-use area, a near-use area different in refractive power from the distance-use area and a progressive area having a refractive power progressively changing between those, the method comprising:

establishing reference lines extending in at least three of radial directions from a center point in a vicinity of a geometric center of the spectacle lens to any one of both ends of the distant-use area, the near-use area, and a center region;

establishing reference lines extending in at least one of radial directions from the center point of the spectacle lens to the other of the distant-use area and the near-use area;

determining an aspheric addition amount for a refractive power that is along each of the reference lines; and

determining an aspheric addition amount, by interpolation, for a refractive power of between the reference lines, wherein

provided that a coordinate system is defined, as viewing the combined refracting surface from front of spectacles being worn, with X-axis in a left-right direction, Y-axis in a vertical direction being a distance direction, Z-axis in a depth direction and the center point as

( x, y, z )=(0, 0, 0),

to represent a coordinate forming a basis of the combined refracting surface as z p and the aspheric addition amount as δ, then a coordinate z t of a combined refracting surface added with the aspheric addition amount is expressed as

z t =z p +δ.

2. A method of designing a spectacle lens having a combined refracting surface in at least one of two refracting surfaces at object and eve sides structuring the spectacle lens, the combined refracting surface having an astigmatism correcting toric surface combined with a progressive refracting surface having a distance-use area, a near-use area different in refractive power from the distance-use area and a progressive area having a refractive power progressively changing between those, the method comprising:

establishing reference lines extending in at least three of radial directions from a center point in a vicinity of a geometric center of the spectacle lens to any one of both ends of the distant-use area, the near-use area, and a center region;

establishing reference lines extending in at least one of radial directions from the center point of the spectacle lens to the other of the distant-use area and the near-use area;

determining an aspheric addition amount for a refractive power that is along each of the reference lines; and

determining an aspheric addition amount, by interpolation, for a refractive power of between the reference lines, wherein

provided that a coordinate system is defined, as viewing the combined refracting surface from front of spectacles being worn, with X-axis in a left-right direction, Y-axis in a vertical direction being a distance direction, Z-axis in a depth direction and the center point as

( x, y, z )=(0, 0, 0),

to represent a radial inclination forming a basis of the combined refracting surface as dz p and a radial inclination determined from the aspheric addition amount as dδ, then a radial inclination dz t of a combined refracting surface added with the aspheric addition amount is expressed as

dz t =dz p +dδ.

3. A method of designing a spectacle lens having a combined refracting surface in at least one of two refracting surfaces at object and eye sides structuring the spectacle lens, the combined refracting surface having an astigmatism correcting toric surface combined with a progressive refracting surface having a distance-use area, a near-use area different in refractive power from the distance-use area and a progressive area having a refractive power progressively changing between those, the method comprising:

establishing reference lines extending in at least three of radial directions from a center point in a vicinity of a geometric center of the spectacle lens to any one of both ends of the distant-use area, the near-use area, and a center region;

establishing reference lines extending in at least one of radial directions from the center point of the spectacle lens to the other of the distant-use area and the near-use area;

determining an aspheric addition amount for a refractive power that is along each of the reference lines; and

determining an aspheric addition amount, by interpolation, for a refractive power of between the reference lines, wherein

provided that a coordinate system is defined, as viewing the combined refracting surface from front of spectacles being worn, with X-axis in a left-right direction, Y-axis in a vertical direction being a distance direction, Z-axis in a depth direction and the center point as

( x, y, z )=(0, 0, 0),

to represent a radial curvature forming a basis of the combined refracting surface as c p and a radial curvature determined from the aspheric addition amount as cδ, then a radial curvature c t of a combined refracting surface added with the aspheric addition amount is expressed as

c t =c p +cδ.

4. A method of designing a spectacle lens having a combined refracting surface in at least one of two refracting surfaces at object and eye sides structuring the spectacle lens, the combined refracting surface having an astigmatism correcting toric surface combined with a progressive refracting surface having a distance-use area, a near-use area different in refractive power from the distance-use area and a progressive area having a refractive power progressively changing between those, the method comprising:

establishing reference lines extending in at least three of radial directions from a center point in a vicinity of a geometric center of the spectacle lens to any one of both ends of the distant-use area, the near-use area, and a center region;

establishing reference lines extending in at least one of radial directions from the center point of the spectacle lens to the other of the distant-use area and the near-use area;

determining an aspheric addition amount for a refractive power that is along each of the reference lines; and

determining an aspheric addition amount, by interpolation, for a refractive power of between the reference lines, wherein

provided that a coordinate system is defined, as viewing the combined refracting surface from front of spectacles being worn, with X-axis in a left-right direction, Y-axis in a vertical direction being a distance direction, Z-axis in a depth direction and the center point as

( x, y, z )=(0, 0, 0),

to represent a coordinate forming a basis of the combined refracting surface as z p and a Koreinich coefficient determined from the aspheric addition amount as cδ, then a coordinate z t of a combined refracting surface added with the aspheric addition amount is expressed, using b p defined in the following equation (1)

b

p

=

2

⁢

z

p

x

2

+

y

2

+

z

p

2

,

(

1

)

as the following equation (2)

z

t

=

(

b

p

+

c

⁢

⁢

δ

)

⁢

r

2

1

+

1

-

(

b

p

+

c

⁢

⁢

δ

)

2

⁢

r

2

(

2

)

where r is a distance from the center point wherein it is expressed as r=(x 2 +y 2 ) 1/2 .

5. A method of designing a spectacle lens having a combined refracting surface in at least one of two refracting surfaces at object and eye sides structuring the spectacle lens, the combined refracting surface having an astigmatism correcting toric surface combined with a progressive refracting surface having a distance-use area, a near-use area different in refractive power from the distance-use area and a progressive area having a refractive power progressively changing between those, the method comprising:

establishing reference lines extending in at least three of radial directions from a center point in a vicinity of a geometric center of the spectacle lens to any one of both ends of the distant-use area, the near-use area, and a center region;

establishing reference lines extending in at least one of radial directions from the center point of the spectacle lens to the other of the distant-use area and the near-use area;

determining an aspheric addition amount for a refractive power that is along each of the reference lines; and

determining an aspheric addition amount, by interpolation, for a refractive power of between the reference lines, wherein

provided that a coordinate system is defined, as viewing the combined refracting surface from front of spectacles being worn, with X-axis in a left-right direction, Y-axis in a vertical direction being a distance direction, Z-axis in a depth direction and the center point as

( x, y, z )=(0, 0, 0),

to represent a coordinate forming a basis of the combined refracting surface as z p and a Koreinich coefficient determined from the aspheric addition amount as kδ, wherein kδ=−e 2 , e is an eccentricity , then a coordinate z t of a combined refracting surface added with the aspheric addition amount is expressed, using b p defined in the following equation (1)

b

p

=

2

⁢

z

p

x

2

+

y

2

+

z

p

2

,

(

1

)

as the following equation (3)

[

Equation

⁢

⁢

⁢

2

]

z

t

=

b

p

⁢

r

2

1

+

1

-

(

1

+

k

⁢

⁢

δ

)

⁢

b

p

2

⁢

r

2

(

3

)

where r is a distance from the center point wherein it is expressed as r=(x 2 +y 2 ) 1/2 .

6. The method in claim 1 , wherein the combined refracting surface is provided in a refracting surface at a side closer to the eye.