Patent Document ID: 9110312
Application ID: 13499882
Patent Status: 1

Claim One:
1. A method for measuring the position of a remarkable virtual point (PRV) that is either the eye's center of rotation (CRO) or a point of which the distance with respect to the edge of the cornea is known of a subject wearing corrective lenses in a spatial reference point associated with the subject's head, in which said method comprises: a step of acquiring at least two images of all or some of the face of the subject by image acquisition means having an optical center, the images being acquired in situations corresponding to distinct angles of vision/head, the subject looking at a focal point (PF) generated by a device and, in one image at most among said at least two images, the direction of the gaze passes, through the optical center of the image acquisition means; a step of estimating the position of the face with respect to the image acquisition means by processing said at least two images; a step of determining, in the said at least two images, coordinates (Xpref, Ypref) of one or more reference points formed by corneal reflection caused by an external lighting source or by the pupil center; characterized in, that the remarkable virtual point is visible at most in the one image at most in which the direction of the gaze passes through the optical center of image acquisition means and the position of the remarkable virtual point is associated by a predetermined geometric relationship with the coordinates of the reference point(s) according to a geometric modeling of the eye focusing on a target, which modeling is three-dimensional or projected onto the plane of the at least two images, said measurement method also comprises a step of 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 coordinates determined for the reference point(s) by using the geometric relationship.