Method and a machine for preparing an ophthalmic lens to be edged

A method for preparing an ophthalmic lens to be edged on the basis of a presentation lens, comprising:

• fixing a first support on one of the faces of the presentation lens, the first support having a shape that defines a first reference point,
• positioning the presentation lens by means of said first support in an optical machine that comprises an image sensor for acquiring images of the presentation lens,
• acquiring, with said image sensor, at least an image of the presentation lens,
• determining, on said acquired image, the shape of the outline of the presentation lens,
• positioning a pupillary point relative to the outline of the presentation lens,
• centering said ophthalmic lens by positioning the outline of the presentation lens relative to the ophthalmic lens so that the pupillary point is superimposed on a centering point of the ophthalmic lens, and
• fixing a second support on one of the faces of the ophthalmic lens, the second support having a shape defining a second reference point, the second support being fixed on the ophthalmic lens so that its second reference point is at a predetermined position relative to the first reference point.