Method of manufacturing progressive power spectacle lens

1. A method of manufacturing a progressive power spectacle lens, comprising:

dividing available vertex powers into a plurality of vertex power groups;

forming one surface of a spectacle lens as a common surface for the vertex powers within each of the plurality of vertex power groups; and

forming an opposite surface of the spectacle lens as a progressive power surface in accordance with a desired vertex power,

wherein condition:

D 1 m i ( Y )≠ D 1 m j ( Y )

is satisfied for at least one value Y which represents a distance from a fitting point in a direction of a main meridian of the progressive power surface of the spectacle lens,

wherein D 1 m (Y) represents a surface power in a direction of a main meridian of the progressive power surface of the spectacle lens, subscripts i and j indicating the spectacle lenses having different vertex powers in the same group.

2. The method according to claim 1 , wherein condition:

D 2 m i ( Y′ )= D 2 m j ( Y′ )

is satisfied for all values of Y ′ which represents a distance on the one surface, along a line where the one surface intersects with a plane including an optical axis of the spectacle lens, from an optical axis that passes a fitting point and a center of an eyeball,

wherein D 2 m (Y′) represents a surface power of the one surface of the spectacle lens, subscripts i and j indicating the spectacle lenses having different vertex powers in the same group.

3. The method according to claim 2 ,

wherein condition:

D 2 m i ( Y′ )= D 2 m j ( Y′ )= D 2 m i (0)= D 2 m j (0)

is satisfied for all values of Y′ of each of the one surfaces.

4. The method according to claim 1 ,

wherein condition:

ASD i ( Y )> ASD j ( Y )

is satisfied for a value Y which represents a distance from a fitting point,

wherein Y≦−15 mm,

wherein P i <P j <−3.00, P i and P j representing the vertex powers at the distance reference points of spectacle lenses having different vertex powers, respectively, subscripts i and j indicating values for the spectacle lenses having different vertex powers in the same group,

wherein ASD(Y) represents the surface astigmatism defined as |D 1 m (Y)−D 1 s (Y)| at the distance Y, D 1 m (Y) representing a surface power in a direction of a main meridian of the progressive power surface of the spectacle lens, D 1 s representing a surface power in a direction perpendicular to the main meridian of the progressive power surface of the spectacle lens.

5. The method according to claim 1 ,

wherein condition:

ASD i ( Y )> ASD j ( Y )

is satisfied for a value Y which represents a distance from a fitting point,

wherein Y≦−15 mm,

wherein P i >P j >+2.00, P i and P j representing the vertex powers at the distance reference points of spectacle lenses having different vertex powers, respectively, subscripts i and j indicating values for the spectacle lenses having different vertex powers in the same group,

wherein ASD(Y) represents the surface astigmatism defined as |D 1 m (Y)−D 1 s (Y)| at the distance Y, D 1 m (Y) representing a surface power in a direction of a main meridian of the progressive power surface of the spectacle lens, D 1 s representing a surface power in a direction perpendicular to the main meridian of the progressive power surface of the spectacle lens.

6. The method according to claim 1 ,

wherein condition:

ASD i ( Y )> ASD j ( Y )

is satisfied for a value Y which represents a distance from a fitting point, subscripts i and j indicating values for the spectacle lenses having different vertex powers in the same group,

wherein Y≧5 mm,

wherein P i >P j >2.00, P 1 and P j representing the vertex powers at the distance reference points of spectacle lenses having different vertex powers, respectively,

wherein ASD(Y) represents the surface astigmatism defined as |D 1 m (Y)−D 1 s (Y)| at a distance Y from the fitting point, D 1 m (Y) representing a surface power in a direction of a main meridian of the progressive power surface of the spectacle lens, D 1 s representing a surface power in a direction perpendicular to the main meridian of the progressive power surface of the spectacle lens.

7. The method according to claim 1 ,

wherein condition:

66 APD i ( Y )>Δ APD j ( Y )

is satisfied for a value Y which represents a distance from a fitting point, subscripts i and j indicating values for the spectacle lenses having different vertex powers in the same group,

wherein Y>0 mm,

wherein P i >P j >2.00, P i and P j representing the vertex powers at the distance reference points of spectacle lenses having different vertex powers, respectively,

wherein ΔAPD(Y) represents a change of mean surface power APD(Y), the mean surface power APD(Y) being defined by (D 1 m (Y)+D 1 s (Y))/2, D 1 m (Y) representing a surface power in a direction of a main meridian of the progressive power surface of the spectacle lens, D 1 s representing a surface power in a direction perpendicular to the main meridian of the progressive power surface of the spectacle lens, the change of mean surface power being defined such that ΔAPD(Y)=|APD(Y)−APD(0)|.

8. The method according to claim 1 , wherein the spectacle lens has a front surface on an object side and a back surface on a eye side, and wherein the front surface is formed as the common surfaces for respective vertex power groups.

9. The method according to claim 1 , wherein the common surface is a spherical surface.

10. The method according to claim 1 , wherein distributions of at least one of astigmatism and mean power of spectacle lenses within a same group and having different vertex powers are substantially similar to each other.

11. A method of manufacturing a progressive power spectacle lens, comprising:

dividing available vertex powers into a plurality of vertex power groups;

forming one surface of a spectacle lens as a common surface for the vertex powers within each of the plurality of vertex power groups; and

forming an opposite surface of the spectacle lens as a progressive power surface in accordance with a desired vertex power,

wherein condition:

D 1 m i ( Y )− D 1 s j ( Y )≠ D 1 m j ( Y )−D 1 s j ( Y )

is satisfied for at least one value Y, Y representing a distance from a fitting point,

wherein D 1 m (Y) represents a surface power in a direction of a main meridian of the progressive power surface of the spectacle lens, subscripts i and j indicating the spectacle lenses having different vertex powers in the same group, and

wherein D 1 s (Y) represents a surface power, in the direction perpendicular to the main meridian.

12. The method according to claim 11 , wherein condition:

D 2 m i ( Y′ )= D 2 m j ( Y′ )

is satisfied for a value Y′ which represents a distance on the one surface, along a line where the one surface intersects with a plane including an optical axis of the spectacle lens, from an optical axis that passes a fitting point and a center of an eyeball,

wherein D 2 m (Y′) represents a surface power of the one surface of the spectacle lens, subscripts i and j indicating the spectacle lenses having different vertex powers in the same group.

13. The method according to claim 12 ,

wherein condition:

D 2 m i ( Y′ )= D 2 m j ( Y′ )= D 2 m i (0)= D 2 m j (0)

is satisfied for at least one value Y′ of each of the one surfaces.

14. The method according to claim 11 ,

wherein condition:

ASD i ( Y )> ASD j ( Y )

is satisfied for a value Y which represents a distance from a fitting point,

wherein Y≦−5 mm,

wherein P i <P j <−3.00, P i and P j representing the vertex powers at the distance reference points of spectacle lenses having different vertex powers, respectively, subscripts i and j indicating values for the spectacle lenses having different vertex powers in the same group,

wherein ASD(Y) represents the surface astigmatism defined as |D 1 m (Y)−D 1 s (Y)| at the distance Y, D 1 m (Y) representing a surface power in a direction of a main meridian of the progressive power surface of the spectacle lens, D 1 s representing a surface power in a direction perpendicular to the main meridian of the progressive power surface of the spectacle lens.

15. The method according to claim 11 ,

wherein condition:

ASD i ( Y )> ASD j ( Y )

is satisfied for a value Y which represents a distance from a fitting point,

wherein Y≦−15 mm,

wherein P i >P j >=2.00, P i and P j representing the vertex powers at the distance reference points of spectacle lenses having different vertex powers, respectively, subscripts i and j indicating values for the spectacle lenses having different vertex powers in the same group,

wherein ASD(Y) represents the surface astigmatism defined as |D 1 m (Y)−D 1 s (Y)| at the distance Y, D 1 m (Y) representing a surface power in a direction of a main meridian of the progressive power surface of the spectacle lens, D 1 s representing a surface power in a direction perpendicular to the main meridian of the progressive power surface of the spectacle lens.

16. The method according to claim 11 ,

wherein condition:

ASD i ( Y )> ASD j ( Y )

is satisfied for a value Y which represents a distance from a fitting point, subscripts i and j indicating values for the spectacle lenses having different vertex powers in the same group,

wherein Y≧5 mm,

wherein P i >P j >+2.00, P i and P j representing the vertex powers at the distance reference points of spectacle lenses having different vertex powers, respectively,

wherein ASD(Y) represents the surface astigmatism defined as |D 1 m (Y)−D 1 s (Y)| at a distance Y from the fitting point, D 1 m (Y) representing a surface power in a direction of a main meridian of the progressive power surface of the spectacle lens, D 1 s representing a surface power in a direction perpendicular to the main meridian of the progressive power surface of the spectacle lens.

17. The method according to claim 11 ,

wherein condition:

Δ APD i ( Y )>Δ APD j ( Y )

is satisfied for a value Y which represents a distance from a fitting point, subscripts i and j indicating values for the spectacle lenses having different vertex powers in the same group,

wherein Y>0 mm,

wherein P i >P j >+2.00, P i and P j representing the vertex powers at the distance reference points of spectacle lenses having different vertex powers, respectively,

wherein ΔAPD(Y) represents a change of mean surface power APD(Y), the mean surface power APD(Y) being defined by (D 1 m (Y)+D 1 s (Y))/2, D 1 m (Y) representing a surface power in a direction of a main meridian of the progressive power surface of the spectacle lens, D 1 s representing a surface power in a direction perpendicular to the main meridian of the progressive power surface of the spectacle lens, the change of mean surface power being defined such that ΔAPD(Y)=|APD(Y)−APD(0)|.

18. The method according claim 11 , wherein the spectacle lens has a front surface on an object side and a back surface on a eye side, and wherein the front surface is formed as the common surfaces for respective vertex power groups.

19. The method according to claim 11 , wherein the common surface is a spherical surface.

20. The method according to claim 11 , wherein distributions of at least one of astigmatism and mean power of spectacle lenses within a same group and having different vertex powers are substantially similar to each other.