Progressive ophthalmic lens

1. A progressive ophthalmic lens comprising:

a front surface and a rear surface, each surface having in each point an altitude, a mean sphere value, and a cylinder value,

the front surface of the lens comprising:

a far vision zone having a far vision reference point,

a near vision zone having a near vision reference point, and

a main meridian,

wherein the front surface is a regressive surface which is a continuous aspheric surface having a zone of decreasing mean sphere value connecting the far vision zone and the near vision zone and has:

a sphere gradient normalized value of less than 7.50·10 −1 mm −1 at any point in a central portion of the lens including a portion of the main meridian, the far vision reference point, and the near vision reference point, and

a cylinder gradient normalized value of less than 1.45 mm −1 at any point in the central portion of the lens.

2. The progressive ophthalmic lens according to claim 1 , wherein at least one surface comprises two micro-markings and a central point located at the center of a segment linking the two micro-markings, and

wherein the central portion of the lens is a circle of 40 mm diameter centered on the central point.

3. A semi-finished spectacle lens blank comprising:

a first regressive surface which is a continuous aspheric surface having a zone of decreasing mean sphere value connecting the far vision zone and the near vision zone, and a second unfinished surface,

the first regressive surface having in each point an altitude, a mean sphere value, and a cylinder value,

the first regressive surface comprising:

a far vision zone having a far vision reference point,

a near vision zone having a near vision reference point, and

a main meridian,

wherein the first regressive surface has a fourth derivative with respect to altitude normalized value of less than 5.0·10 −5 mm −2 ·diopter −1 at any point in at least a central portion of the blank including a portion of the main meridian, the far vision reference point, and the near vision reference point, and

wherein the first regressive surface has:

a sphere gradient normalized value of less than 7.50·10 −1 mm −1 at any point in the central portion, and

a cylinder gradient normalized value of less than 1.45 mm −1 at any point in the central portion.

4. The semi-finished spectacle lens blank of claim 3 , further comprising markings defining a position of a central point of the blank,

wherein the central portion of the blank is a circle of 40 mm diameter centered on the central point.

5. A method for manufacturing a progressive ophthalmic lens, comprising:

providing data relative to a wearer;

selecting a semi-finished lens blank according to claim 4 ;

carrying out an optical optimization of the lens based on the data relative to the wearer and on data relative to the first regressive surface of the blank; and

providing the selected semi-finished lens blank and surfacing or molding the unfinished surface of the blank according to the result of the optical optimization.

6. A method for manufacturing a progressive ophthalmic lens, the method comprising:

providing data relative to a wearer;

selecting a semi-finished lens blank according to claim 3 ;

carrying out an optical optimization of the lens based on the data relative to the wearer and on data relative to the first regressive surface of the blank; and

providing the selected semi-finished lens blank and surfacing or molding the unfinished surface of the blank according to the result of the optical optimization.

7. A set of apparatuses for manufacturing a progressive ophthalmic lens and/or a semi-finished lens blank, wherein the apparatuses are configured to execute the method according to claim 6 .

8. A computer program product comprising one or more stored sequence of instruction that is accessible to a processor and which, when executed by the processor, causes the processor to execute the method of claim 6 .

9. A semi-finished spectacle lens blank comprising:

a first regressive surface which is a continuous aspheric surface having a zone of decreasing mean sphere value connecting the far vision zone and the near vision zone, and a second unfinished surface,

the first regressive surface having in each point an altitude, a mean sphere value, and a cylinder value,

the first regressive surface comprising:

a far vision zone having a far vision reference point,

a near vision zone having a near vision reference point, and

a main meridian,

wherein the first regressive surface has:

a sphere gradient normalized value of less than 7.50·10 −1 mm −1 at any point in a central portion of the blank including a portion of the main meridian, the far vision reference point, and the near vision reference point, and

a cylinder gradient normalized value of less than 1.45 mm −1 at any point in the central portion.

10. The semi-finished spectacle lens blank of claim 9 , further comprising markings defining a position of a central point of the blank,

wherein the central portion of the blank is a circle of 40 mm diameter centered on the central point.

11. A method for manufacturing a progressive ophthalmic lens, the method comprising:

providing data relative to a wearer;

selecting a semi-finished lens blank according to claim 9 ;

carrying out an optical optimization of the lens based on the data relative to the wearer and on data relative to the first regressive surface of the blank; and

providing the selected semi-finished lens blank and surfacing or molding the unfinished surface of the blank according to the result of the optical optimization.

12. A method for manufacturing semi-finished lens blank, the method comprising:

defining a first surface and a second unfinished surface, the first surface having in each point an altitude, a mean sphere value, and a cylinder value;

defining a far vision zone having a far vision reference point, a near vision zone having a near vision reference point, a main meridian, and a central portion of the first surface including a portion of the main meridian, the far vision reference point, and the near vision reference point;

determining the first surface being a first regressive surface which is a continuous aspheric surface having a zone of decreasing mean sphere value connecting the far vision zone and the near vision zone and having:

a regression of the mean sphere value between at least a portion of the far vision zone and at least a portion of the near visions zone,

a sphere gradient normalized value of less than 7.50·10 −1 mm −1 at any point in the central portion, and

a cylinder gradient normalized value of less than 1.45 mm −1 at any point in the central portion; and

surfacing or molding the first surface.

13. A set of apparatuses for manufacturing a progressive ophthalmic lens and/or a semi-finished lens blank, wherein the apparatuses are configured to execute the method according to claim 12 .

14. A computer program product comprising one or more stored sequence, of instruction that is accessible to a processor and which, when executed by the processor, causes the processor to execute the method of claim 12 .

15. A non-transitory computer readable medium carrying out one or more sequences of instructions of the computer program product of claim 14 .

16. A method for manufacturing a progressive ophthalmic lens, comprising:

providing data relative to a wearer;

defining far vision zone having a far vision reference point, a near vision zone having a near vision reference point, and a main meridian;

defining a first surface of the lens being a first regressive surface which is a continuous aspheric surface having a zone of decreasing mean sphere value connecting the far vision zone and the near vision zone and having:

a regression of the mean sphere value between at least a portion of the far vision zone and at least a portion of the near visions zone,

a sphere gradient normalized value of less than 7.50·10 −1 mm −1 at any point in a central portion of the lens including a portion of the main meridian, the far vision reference point and the near vision reference point, and

a cylinder gradient normalized value of less than 1.45 mm −1 at any point in the central portion of the lens;

carrying out an optical optimization of the lens based on the data relative to the wearer and on data relative to the first surface of the lens;

determining a second surface of the lens according to the result of the optical optimization; and

surfacing or molding the first and second surfaces.

17. A set of apparatuses for manufacturing a progressive ophthalmic lens and/or a semi-finished lens blank, wherein the apparatuses are configured to execute the method according to claim 16 .

18. A computer program product comprising one or more stored sequence of instruction that is accessible to a processor and which, when executed by the processor, causes the processor to execute the method of claim 16 .