Apparatus, accessory, and method for determining the diameter of a lens to be mounted onto a glasses frame, or for controlling the mounting of a glasses lens onto a glasses frame

An electronic tablet accessory for determining the diameter of a lens intended to be mounted in a spectacle frame or for checking the mounting of a lens in a spectacle frame, said accessory comprising:

• a fixing device intended to be fixed on an electronic tablet having a flat screen;
• and
• a spectacle frame support linked mechanically to the fixing device, the spectacle frame support being suitable for holding said spectacle frame in a fixed position in the vicinity of the flat screen,
• the fixing device and the spectacle frame support having at least one opening between a rim of said frame in said fixed position, and the surface of the flat screen, when the fixing device is fixed on the electronic tablet, said opening being suitable for allowing an operator to view a graphical image displayed on the flat screen of the tablet by projection through said opening, so as to determine the diameter of a lens intended to be mounted in a rim of said spectacle frame or to check the mounting of a lens in said spectacle frame.

A procedure for checking the mounting of at least one ophthalmic compensation lens in a spectacle frame, said lens comprising at least one physical marking, the checking procedure comprising the following steps:

• recording at least one digital image comprising at least one graphical reference marker representative of a face-on view of the ophthalmic compensation lens and/or of the patient intended to wear the ophthalmic compensation lens mounted in said frame;
• digital processing of said image, suitable for deforming the graphical image displayed one half-image at a time, respectively right or left, as a function of the distance L from the sagittal plane of the frame generating a projected image;
• displaying said projected image on a digital tablet screen;
• positioning the frame comprising said at least one ophthalmic compensation lens, a face of the lens being placed on the surface of the screen of the tablet;
• and
• aligning said frame in relation to the projected image displayed on the screen so as to allow a visual check of the position of the at least one physical marking by projection in relation to the position of the at least one corresponding graphical reference marker in the projected image displayed on the screen.