Measurement method and equipment for the customization and mounting of corrective ophtalmic lenses

Method for determining the Frankfort plane of a subject, including:

• for each eye of the subject, the determination of the position of a remarkable virtual point of the eye by applying the method according to any one of the previous claims;
• the determination of the position of the sub-orbital point of each eye by a predetermined geometric relationship with the remarkable virtual point of said eye;
• the determination of the position of the subject's tragion in at least one of the images taken during the step of determining the remarkable virtual point;
• the determination of the Frankfort plane on the basis of the position of the tragion and the sub-orbital points.

System for measuring the position of a remarkable virtual point (PRV) associated with the face of a subject wearing a corrective lens at a spatial reference point associated with the corrective lens, comprising:

• means for acquisition (2) of at least two images of all or some of the subject's face;
• a device for calculating the position of the face with respect to the image acquisition means by image processing;
• means for determining, in the images, coordinates (Xpref, Ypref) of one or more reference points associated with the face;
• characterised in that the remarkable virtual point is visible in at least one image and the position of the remarkable virtual point is associated by a predetermined geometric relationship with the coordinates of the reference point(s), and said measurement system also comprises a device for calculating at least one of the coordinates (XPRV, YPRV, ZPRV) of the remarkable virtual point (PRV) at the spatial reference point on the basis of the determined coordinates of the reference point(s) by using the geometric relationship.