Method of manufacturing an optical lens

1. A method of manufacturing an optical lens, the method comprising:

a lens member providing step during which a lens member comprising a first surface and a first reference system identified by engraved markings on the first surface are provided;

a surface data providing step during which surface data corresponding to a second surface of the optical lens to be manufactured are provided;

a second markings providing step during which second markings are provided on the lens member defining a second reference system;

a marking positioning error providing step during which a marking positioning error between the second markings and the engraved markings is provided;

taping step during which an adhesive tape is provided on the first surface of the lens member; and

a manufacturing step during which the second surface of the optical lens is manufactured according to the surface data and the marking positioning error such that the relative position of the first and second surfaces is respected.

2. Method according to claim 1 , wherein the second markings are provided on the first surface of the lens member.

3. Method according to claim 1 , wherein the second markings are surface markings, for example printed on the first surface of the lens member.

4. Method according to claim 1 , wherein the manufacturing step comprises:

a blocker providing step during which a blocker with a blocker reference system is provided; and

a blocking step during which the lens member is blocked on the blocker in a blocking position, the blocking position being determined with respect to the blocker reference system so as to compensate the marking positioning error.

5. Method according to claim 1 , wherein the manufacturing step comprises:

a blocker providing step during which a blocker with a blocker reference system is provided;

a blocking step during which the lens member is blocked on a blocker in a blocking position; and

a configuration step during which the operational parameters of a lens machining tool are configured according to the marking positioning error such that the relative position of the first and second surfaces is respected.

6. Method according to claim 4 , wherein the manufacturing step comprises:

a blocker providing step during which a blocker is provided with the blocker reference system;

a blocking step during which the lens member is blocked on a blocker in a blocking position;

a comparing step during which the blocking positioning error between the second reference system and the blocker reference system is determined; and

a configuration step during which the operational parameters of a lens machining tool are configured according to the blocking positioning error such that the relative position of the first and second surfaces is respected.

7. A method according to claim 6 , comprising viewing the second markings through the lens member and wherein the refractive properties of the lens member are taken into account when determining the positioning of the second markings.

8. A method according to claim 1 , wherein after the manufacturing step, the method further comprises a further marking step during which further markings are engraved on the manufactured second surface according at least to the marking positioning error.

9. A method according to claim 1 , wherein the second markings are removed after the second surface is manufactured.

10. 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 data processing device to perform the method of claim 1 .

11. A computer-readable medium having computer-executable instructions to enable a computer system to perform the method of claim 1 .