Patent ID: 8360580

Claim:
A method of measuring a position, in a horizontal direction of the sagittal plane (PSAG), of a remarkable point (CROD, CROG) of an eye (OD, OG) of a subject in a frame of reference (O,X,Y,Z) associated with the head of said subject, the method comprising the steps of: S1) arranging the subject's head in a first relative posture (O 1 ,X 1 ,Y 1 ,Z 1 ) relative to the entry pupil ( 95 ) of a single image capture appliance ( 90 ) placed facing the subject's face; S2) in said first relative posture, using the single image capture appliance ( 90 ) to capture, at a first point in time, a first plane image of the eye; S3) in said first image, identifying the image of a first predetermined reference point (RCG 1 , RCD 1 ) of the eye; S4) arranging the subject's head in a second relative posture (O 2 ,X 2 ,Y 2 ,Z 2 ) relative to the entry pupil ( 95 ) of the image capture appliance ( 90 ), the second relative posture being distinct from the first relative posture (O 1 ,X 1 ,Y 1 ,Z 1 ); S5) in the second relative posture, using the single image capture appliance ( 90 ) to capture, at a second point in time, a second plane image of the eye, the first and second points in time being different; S6) in said second image, identifying the image of a second predetermined reference point (RCG 2 , RCD 2 ) of the eye; and S9) calculating said position of the remarkable point (CROD, CROG) of the eye as a function exclusively of the first and second plane images of the first and second reference points (RCG 1 , RCD 1 , RCG 2 , RCD 2 ) of the eye provided by said single image capture appliance ( 90 ), and of first and second values (APIV 1 , APIV 2 ) of a posture parameter (APIV) associated respectively with the first and second relative postures, wherein said values of the posture parameter (APIV) are calculated using the following steps: placing a position-identification element ( 60 , 70 , 80 ; 700 ; 800 ) on the head of the subject, said element having at least one known geometrical characteristic; for each of the first and second plane images captured in each relative posture by means of the image capture appliance incorporating a plane image of the position-identification element ( 60 , 70 , 80 ; 700 ; 800 ), processing said image to measure a geometrical characteristic depending on the known geometrical characteristic of the position-identification element; and calculating the different values of the posture parameter (APIV) for the different postures as a function of said measured geometrical characteristic of the captured image of the position-identification element and of the known geometrical characteristic of the position-identification element.