Method for providing a referencing element to an optical lens member

1. A method for providing a referencing element to an optical lens member, the method comprising:

measuring a first optical surface of an optical lens member, the optical lens member comprising the first optical surface comprising a surface design associated with a first reference system including translational and rotational parameters and a second optical surface to be manufactured, the first and second optical surfaces being connected by an external periphery surface,

determining the first reference system, wherein the first reference system is determined according to the shape and orientation of the first optical surface, wherein the first reference system is unique to the first optical surface; and

adding a referencing element to the optical lens member, wherein the referencing element identifies the first reference system, the referencing element comprising at least a sub-surface element located between the first and second optical surfaces.

2. The method according to claim 1 , wherein the sub-surface referencing element comprises a plurality of sub-surface markings, the sub-surface markings defining a plane.

3. The method according to claim 1 , wherein the referencing element comprises sets of coplanar sub-surface markings, each set of markings defining a different plane.

4. The method according to claim 1 , further comprising:

arranging the referencing element so that when an optical lens is manufactured from said optical lens member, said referencing element being placed on the optical lens out of the wearer's principal visual field.

5. The method according to claim 1 , further comprising:

molding the first optical surface of the optical lens member.

6. The method according to claim 1 , further comprising:

machining the first optical surface of the optical lens member.

7. The method according to claim 1 , further comprising:

additive manufacturing the first optical surface of the optical lens member.

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

measuring a first optical surface of an optical lens member, the optical lens member comprising the first optical surface comprising a surface design associated with a first reference system including translational and rotational parameters and a second optical surface to be manufactured, the first and second optical surfaces being connected by an external periphery surface;

determining the first reference system, wherein the first reference system is determined according to the shape and orientation of the first optical surface, wherein the first reference system is unique to the first optical surface;

adding a referencing element to the optical lens member, wherein the referencing element identifies the first reference system, the referencing element comprising at least a sub-surface element located between the first and second optical surfaces;

positioning an optical lens member, so that the first face of the optical lens member is placed on a blocker associated with a blocker reference system and positioned in a blocking position with respect to the blocker reference system using the referencing element;

blocking the optical lens member on the blocker in the blocking position; and

manufacturing the second surface of the optical lens member according to surface data corresponding to the second optical surface of the optical lens to be manufactured.

9. A non-transitory computer readable medium carrying one or more sequences of instructions of a computer program which, when executed by a processor, causes the processor to perform a method, the method comprising:

controlling a sensor for measuring a first optical surface of an optical lens member, the optical lens member comprising the first optical surface comprising a surface design associated with a first reference system including translational and rotational parameters and a second optical surface to be manufactured, the first and second optical surfaces being connected by an external periphery surface,

determining the first reference system, wherein the first reference system is determined according to the shape and orientation of the first optical surface, wherein the first reference system is unique to the first optical surface, and

adding a referencing element to the optical lens member,

the referencing element identifying the first reference system, the referencing element comprising at least a sub-surface element located between the first and second optical surfaces.