Manufacturing method and supplying method of spectacle lenses

1. A manufacturing method of a spectacle lens at least one of whose front and back surfaces is aspherical, comprising:

preparing a plurality of types of semifinished lens blanks that are different in base curve for each of predetermined vertex powers;

selecting one type of said semifinished lens blank among said plurality of types of said semifinished lens blanks that are prepared for the same vertex power based on considerations of optical performance and outward appearance; and

processing a back surface of the selected semifinished lens blank to form a finished lens according to a required specification for the spectacle lens.

2. The manufacturing method according to claim 1 , wherein three or more types of the semifinished lens blanks are prepared for each of said predetermined vertex powers.

3. The manufacturing method according to claim 1 , wherein any pair of said finished lenses, which are made from said semifinished lens blanks prepared for the same vertex power, satisfy the following condition (1) when SPH <0, CYL≦0 and satisfy the condition (2) when SPH>0, CYL≧0:

(1) ΔD1m(15) i +ΔD2m(15) i >ΔD1m(15) j +ΔD2m(15) j

(2) ΔD1m(15) i +ΔD2m(15) i <ΔD1m(15) j +ΔD2m(15) j

where

SHP is a spherical power (unit: diopter),

CYL is a cylindrical power (unit: diopter),

D1m(h) and D2m(h) are surface powers of the front and back surfaces (unit: diopter) at the point whose distance from the optical axis of said finished lens is h (unit: mm) in a plane that contains said optical axis,

ΔD1m(h) is a variation of surface power of the front surface and is obtained by D1m(h)−D1m(0),

ΔD2m(h) is a variation of surface power of the back surface and is obtained by D2m(h)−D2m(0), and

the subscript “i” represents the values of the finished lens that has smaller base curve and the subscript “j” represents the values of the finished lens that has larger baser curve as described by D1m(0) i <D1m(0) j .

4. The manufacturing method according to claim 1 , wherein the front surface of said finished lens is a rotationally-symmetrical aspherical surface and the back surface is selected from among a spherical surface and a toric surface.

5. The manufacturing method according to claim 1 , wherein the front surface of said finished lens is selected from among a spherical surface and a toric surface and the back surface is a rotationally-symmetrical aspherical surface.

6. The manufacturing method according to claim 1 , wherein both of the front and back surfaces of said finished lens are aspherical surfaces.

7. The manufacturing method according to claim 1 , wherein average power errors and astigmatisms of said finished lenses, which are made from said semifinished lens blanks having different base curves prepared for the same vertex power, are approximately identical within 30 degrees of visual angle.

8. The manufacturing method according to claim 1 , wherein differences of average power errors and differences of astigmatisms among said finished lenses, which are made from said semifinished lens blanks having different base curves prepared for the same vertex power, are not greater than 0.1 diopter within 30 degrees of visual angle.

9. The manufacturing method according to claim 1 , wherein one type of said semifinished lens blanks prepared for one vertex power has an approximately identical base curve with one type of said semifinished lens blanks prepared for another vertex power.

10. The manufacturing method according to claim 1 , wherein differences of base curves between one type of said semifinished lens blanks prepared for one vertex power and one type of semifinished lens blanks prepared for ether another vertex power is not greater than 0.2 diopter.

11. A manufacturing method of a spectacle lens whose at least one of whose front and back surfaces is aspherical, comprising:

dividing the entire range of available vertex power of a spectacle lens into a plurality of sections; preparing a plurality of types of semifinished lens blanks that are different in base curve for each of said sections;

determining one of said sections according to a required specification of the spectacle lens;

selecting one type of said semifinished lens blank among said plurality of types of said semifinished lens blanks that are prepared for the same sections based on considerations of optical performance and of outward appearance; and

processing a back surface of the selected semifinished lens blank to form a finished lens according to a required specification for the spectacle lens.

12. A supplying method of a spectacle lens whose at least one of whose front and back surfaces is aspherical, comprising:

preparing a plurality of types of finished lenses that are different in base curve for the same vertex power, average power errors and astigmatisms of said finished lenses being approximately identical within 30 degrees of visual angle; and

selecting one type of said finished lenses among said plurality of types of said finished lenses based on consideration of optical performance and of outward appearance and a required specification for the spectacle lens.

13. A method for manufacturing a spectacle lens, at least one of a back surface and a front surface of the spectacle lens being aspherical, the manufacturing method comprising:

preparing a plurality of types of semifinished lens blanks for each of a plurality of predetermined vertex powers, each of the plurality of types of semifinished lens blanks having a different base curve;

selecting one type of semifinished lens blanks from among said plurality of types of said semifinished lens blanks that have the same vertex power based on considerations of optical performance and aesthetics; and

processing a back surface of the selected semifinished lens blank to form a finished lens according to a required specification for the spectacle lens.