Process for controlling a lens manufacturing process

1. A process for controlling a spectacle lens manufacturing process comprising the steps of:

a) manufacturing a master lens according to a manufacturing process using a manufacturing device,

b) measuring by using at least a measuring device at least one parameter of the master lens of step a),

c) recording the value of the parameter,

d) repeating regularly step a) to c) and checking the evolution of the parameter over time,

wherein the evolution of at least one parameter of the manufacturing device used during the lens manufacturing process is checked over time and the evolution over time of at least one parameter of the master lens is related with the evolution over time of the at least one parameter of the manufacturing device.

2. The process according to claim 1 , wherein the master lens has a different geometrical and/or optical parameter and/or made of a different material than the lenses to be manufactured during the manufacturing process.

3. The process according to claim 1 or 2 , wherein at least one of the measured parameters of the master lens is an optical parameter.

4. The process according to claim 1 or 2 , wherein the master lens is a progressive addition lens and wherein at least one of the measured parameters of the master lens is an optical and/or a geometrical parameter.

5. The process according to claim 4 , wherein said at least one of the measured parameters of the master lens is a parameter in the far and/or the near vision zone.

6. The process according to claim 1 , wherein the optical parameter is measured using a frontofocometer.

7. The process according to claim 1 , wherein the optical parameter is measured using an optical mapping device.

8. The process according to claim 1 , comprising the step of providing to the manufacturing device a digital file including the master lens design.

9. The process according to claim 1 , comprising a feedback loop between the process for controlling a lens and the manufacturing device using the evolution of the at least one measured parameter of the master lens.

10. The process according to claim 1 , wherein a reference master lens is provided or manufactured and at least one measuring device is checked over time by measuring at least one parameter of the reference master lens.

11. The process according to claim 10 , wherein the master lenses manufactured when repeating regularly step a) to c) have the same design as the reference master lens.

12. The process according to claim 10 or 11 , wherein the at least one parameter measured on the master lens is the same as the at least one parameter measured on the reference master lens.

13. The process according to claim 10 , wherein step d) further comprises checking the evolution of the measured at least one parameter of the reference master lens.

14. Manufacturing process for manufacturing a spectacle lens using a manufacturing device comprising the steps of:

providing a lens blank,

blocking the lens blank,

surfacing at least one surface of the lens blank,

wherein the manufacturing process is checked by a process according to claim 1 .

15. The process according to claim 1 or 14 , wherein the process includes a progressive lens surfacing process.

16. The process according to claim 15 , wherein the lens surfacing process is a digital surfacing process.

17. The process according to claim 1 or 14 , wherein the process comprises a feedback loop between the process for controlling a lens and the manufacturing device using the evolution of the at least one physical parameter of the regularly manufactured master lenses.

18. A computer program product for a data-processing device, the computer program product comprising a set of instructions which, when loaded into the data-processing device, causes the device to perform all of the steps of the processes as claimed in claim 1 or 14 .