Process implemented by computer means for controlling an ophthalmic lens manufacturing process, characterized in that it comprises: (i) a step of determining at least six position parameters defining the relative position of a manufactured derivable surface of said lens relative to a reference surface, wherein said step of determining at least six position parameters comprises: - a nominal surface providing step during which a nominal surface expressed in a nominal frame of reference and corresponding to the theoretical derivable surface to be manufactured with the nominal value of the position parameters defining the relative position of the nominal surface relative to the reference surface is provided, - a measured surface providing step during which a measured surface of the manufactured derivable surface expressed in the nominal frame of reference is provided, - a deformation surface providing step during which at least one deformation surface defined by at least one adjustable deformation parameter is provided, - a composed surface determining step during which a composed surface is determined by adding the measured surface and the deformation surface, - a parameters determining step during which the position parameters and at least one deformation parameter are determined by minimizing the difference between the nominal surface and the composed surface, and in that at further comprises: (ii) an error surface determining step during which the error surface corresponding to the difference between the measured surface positioned relative to the reference surface by using the six position parameters and the nominal surface is determined, (iii) a controlling step during which the error surface is controlled. (i) a step of determining at least six position parameters defining the relative position of a manufactured derivable surface of said lens relative to a reference surface, wherein said step of determining at least six position parameters comprises: - a nominal surface providing step during which a nominal surface expressed in a nominal frame of reference and corresponding to the theoretical derivable surface to be manufactured with the nominal value of the position parameters defining the relative position of the nominal surface relative to the reference surface is provided, - a measured surface providing step during which a measured surface of the manufactured derivable surface expressed in the nominal frame of reference is provided, - a deformation surface providing step during which at least one deformation surface defined by at least one adjustable deformation parameter is provided, - a composed surface determining step during which a composed surface is determined by adding the measured surface and the deformation surface, - a parameters determining step during which the position parameters and at least one deformation parameter are determined by minimizing the difference between the nominal surface and the composed surface, and in that at further comprises: - a nominal surface providing step during which a nominal surface expressed in a nominal frame of reference and corresponding to the theoretical derivable surface to be manufactured with the nominal value of the position parameters defining the relative position of the nominal surface relative to the reference surface is provided, - a measured surface providing step during which a measured surface of the manufactured derivable surface expressed in the nominal frame of reference is provided, - a deformation surface providing step during which at least one deformation surface defined by at least one adjustable deformation parameter is provided, - a composed surface determining step during which a composed surface is determined by adding the measured surface and the deformation surface, - a parameters determining step during which the position parameters and at least one deformation parameter are determined by minimizing the difference between the nominal surface and the composed surface, (ii) an error surface determining step during which the error surface corresponding to the difference between the measured surface positioned relative to the reference surface by using the six position parameters and the nominal surface is determined, (iii) a controlling step during which the error surface is controlled.