Method for mounting ophthalmic lenses
AssigneeEssilor International
InventorsNathalie Bar, Bruno Decreton, Thierry Bonnin, Berangere Donetti, Gilles Le Saux
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Abstract
The invention relates to a method for fitting, in a frame, a progressive ophthalmic lens prescribed for a wearer. It proposes that only the horizontal position of the wearer's pupil be measured on the wearer. From this measurement, and from the total height of the pattern of the frame, the lens is positioned in the frame, and is then machined and fitted into the frame. The invention makes it possible, when fitting lenses, to avoid the errors brought about by the measuring of the height of the wearer's pupil with respect to the frame.
Claims12
A method for fitting, in a frame, an ophthalmic lens prescribed for a wearer, the method comprising the steps of:
- measuring the horizontal position of the wearer's pupil;
- determining the total height (B) of the pattern of the frame;
- positioning the lens in the frame according to the horizontal position measured and according to the total height (B);
- and
- trimming the lens and fitting the lens in the frame,
- wherein the positioning step involves positioning, at a distance h vertically above the lower edge of the pattern of the frame, the point of the lens through which the wearer's gaze has to pass when he has his head up and is looking at infinity, with
- h=Int(0.5B+5.5) for 31≦B≦35 (1)
- h=Int(0.5B+4.5) for 36≦B≦50 (2)
- where B is the total height of the pattern of the frame, and Int is the function for the integer part.
A method for fitting, in a frame, a progressive ophthalmic lens prescribed for a wearer, on which microetchings are embodied, the method comprising the steps of
- measuring the horizontal position of the wearer's pupil;
- determining the total height (B) of the pattern of the frame;
- positioning the lens in the frame according to the horizontal position measured and according to the total height (B);
- and
- trimming the lens and fitting the lens in the frame,
- wherein the positioning step involves positioning, at a distance h vertically above the lower edge of the pattern of the frame, the middle of the microetchings, with
- h=Int (0.5B+5.5−d) for 31≦B≦35 (3)
- h=Int (0.5B4.5−d) for 36≦B≦50 (4)
- where B is the total height of the pattern of the frame, and Int is the function for the integer part and d is the vertical distance on the lens between the middle of the microetchings and the point of the lens through which the wearer's gaze has to pass when he has his head up and is looking at infinity.
Dependencies are inferred from the claim text.