progressive ophthalmic lens, semi-finished spectacle lens model, method for making semi-finished len

专利摘要:
PROGRESSIVE OPHTHALMIC LENS The present invention relates to a progressive ophthalmic lens comprising a front surface and a rear surface, each surface having at each point an altitude, an average sphere value and a cylinder value, the front surface of the lens comprising : - a far-sighted area that has a far-sighted reference point; - a close view area that has a close view reference point; - a main meridian, where the front surface is regressive and has: - a normalized sphere gradient value of less than 7.50. 10 ^ -1 ^ mm ^ -1 ^ at any point on a central portion of the lens that includes a portion of the main meridian (32), the far-sight reference point (FV), and the approximate-view reference point (NV) ); - a normalized cylinder gradient value of less than 1.45 mm ^ -1 ^ anywhere in the central portion of the lens.
公开号:BR112013024787B1
申请号:R112013024787-8
申请日:2012-03-22
公开日:2020-10-13
发明作者:Hélène De Rossi；Jérôme Moine；Carlos Rego；Mathieu Guillot
申请人:Essilor International；
IPC主号:

专利说明:

FIELD OF INVENTION
[0001] The present invention relates to a progressive ophthalmic lens. The invention also relates to a semi-finished lens model that has a first aspherical surface and a second unfinished surface that is intended to be further machined to form a progressive ophthalmic lens. The invention also relates to a method for making such a progressive ophthalmic lens and such a semi-finished lens model. BACKGROUND OF THE INVENTION
[0002] A user may be prescribed a correction of positive or negative optical power. The ophthalmic prescription may include a prescription for potency and / or astigmatism. For presbyopic users, the value of the power correction is different for distant vision and close vision due to the difficulties of accommodation in close vision. The prescription thus comprises a power value for distant vision and an addition that represents the increase in power between the distant view and the approximate view. The addition qualifies as a prescribed addition. Ophthalmic lenses suitable for presbyopic users are multifocal lenses, the most suitable of which are progressive multifocal lenses.
[0003] The ophthalmic prescription also includes an astigmatism prescription. Such prescription is produced by the ophthalmologist in the form of a pair formed by a geometric axis value (in degrees) and an amplitude value (in diopters). The amplitude value represents the difference between the minimum and maximum power in a given direction that allows to correct a user's visual defect. According to the chosen convention, the geometric axis represents the orientation of one of the two powers in relation to a reference geometric axis and in the chosen direction of rotation. Usually, the TABO convention is used. In this convention, the geometric axis of reference is horizontal and the direction of rotation is counterclockwise for each eye, when looking at the user. A geometric axis value of + 45 ° therefore represents an obliquely oriented geometric axis that, when looking at the user, extends from the quadrant located above on the right to the quadrant located below on the left. Such an astigmatism prescription is measured in the user looking in distant view. The term «astigmatism» is used to designate the pair (amplitude, angle); although the use is not strictly correct, this term is also used to refer to the breadth of astigmatism. The person skilled in the art can understand from the context, what meaning should be considered. It is also known to the person skilled in the art that the prescribed power and astigmatism of a user are generally called the SPH sphere, CYL cylinder and geometric axis.
[0004] To obtain a progressive ophthalmic lens corresponding to a user's prescription, a semi-finished ophthalmic lens model can be supplied by a lens manufacturer. Generally, a semi-finished ophthalmic lens model comprises a first surface corresponding to an optical reference surface, for example, a progressive surface in the case of traditional progressive addition lenses and a second unfinished surface. A semi-finished lens model that has suitable optical characteristics is selected based on the user's prescription and the unfinished surface is machined and polished by a prescription laboratory in order to obtain a prescription-compliant lens. The semi-finished lens model can be produced by molding or digital flattening. The unfinished surface can be machined by digital planing.
[0005] A progressive ophthalmic lens can also be obtained by directly machining both surfaces using digital planing equipment. A tiered lens model is provided; a first aspherical surface is machined and a second aspherical surface is machined, the second aspherical surface being determined by optical optimization based on data relating to the first aspheric surface and data relating to the user. A prescription ophthalmic lens is thus obtained.
[0006] Whichever technology is used - starting with a semi-finished lens model or machining both surfaces by digital planing - precise positioning of the lens on the digital planing machine is required to ensure that the optical characteristics of the lens are met.
[0007] Document No. WO-A-2010/072749 describes a method of manufacturing an ophthalmic lens by digital flattening and identifies the problem of precise positioning of the lens member in a blocker. SUMMARY OF THE INVENTION
[0008] The invention aims to facilitate the manufacture of a progressive ophthalmic lens by maintaining the optical quality of the lens.
[0009] This objective is achieved with a progressive ophthalmic lens comprising a front surface and a rear surface, where each surface has an altitude, an average sphere value and a cylinder value at each point, the front surface being the lens comprises: - a far-sighted area that has a far-sighted reference point; - a close view area that has a close view reference point; - a main meridian, where the front surface is regressive and has: - a normalized sphere gradient value of less than 7.50.101 mm1 at any point in a central portion of the lens that includes a portion of the main meridian, the point distant vision reference point and approximate vision reference point; - a normalized cylinder gradient value of less than 1.45 mm1 at any point in the central portion of the lens.
[00010] According to one embodiment, the front surface of the lens additionally has a derivative quarter with respect to the normalized altitude value of less than 5,0.10'5 mnr2.dioptr’'1 at any point in the central portion of the lens.
[00011] The objective of the invention is also achieved with a progressive ophthalmic lens comprising a front surface and a rear surface, in which each surface has at each point, an altitude, an average sphere value and a cylinder value, being that the front surface of the lens comprises: - a remote viewing area that has a remote viewing reference point; - a close view area that has a close view reference point; - a main meridian, where the front surface is regressive and has a fourth derivative with respect to the normalized altitude value of less than 5.0.10'5 mnr2.dioptr''1 anywhere in a central portion of the lens that includes a main meridian portion, the distant view reference point and the approximate view reference point.
[00012] According to one embodiment, at least one surface of the lens comprises two micro-markings and a central point located in the center of a segment that connects the two micro-markings, the central portion of the lens being a 40 mm diameter centralized circle at the central point.
[00013] The purpose of the invention is also achieved with a semi-finished spectacle lens model that has a first regressive surface and a second unfinished surface, the first regressive surface having, at each point, an altitude, an average sphere value and a cylinder value, in which the first regressive surface comprises a zone of distant view which has a reference point of distance view, a zone of approximate view which has a reference point of approximate view, a main meridian and in which the The first regressive surface has a fourth derivative in relation to the normalized altitude value of less than 5.0.10 5 mnr2.dioptria-1 at any point in at least one central portion of the model that includes a portion of the main meridian, the reference point wide-view and close-up reference point.
[00014] According to one embodiment, the first regressive surface additionally has: - a normalized sphere gradient value of less than 7.50.101 mm1 at any point in the central portion; and - a normalized cylinder gradient value of less than 1.45 mm1 at any point in the central portion.
[00015] The objective of the invention is also achieved with a semi-finished glasses lens model that has a first regressive surface and a second unfinished surface, the first regressive surface having, at each point, an altitude, an average sphere value and a cylinder value, in which the first regressive surface comprises a zone of distant view which has a reference point of distance view, a zone of approximate view which has a reference point of approximate view, a main meridian and in which the first regressive surface has: - a normalized sphere gradient value of less than 7.50.101 mm1 at any point in a central portion that includes a portion of the main meridian, the distant view reference point and the vision reference point approximate; and - a normalized cylinder gradient value of less than 1.45 mm1 at any point in the central portion.
[00016] According to one modality, the model has markings that define a position at a central point of the model, the central portion of the model being a 40 mm diameter circle centered at the central point.
[00017] The invention also relates to a method for manufacturing a semi-finished lens model that comprises the steps of: - defining a first surface and a second unfinished surface, the first surface having an altitude at each point, a sphere value average and a cylinder value; - define a zone of distant vision that has a reference point of distant vision, a zone of approximate views that has a reference point of approximate vision, a main meridian and a central portion of the first surface that includes a portion of the main meridian, the distant view reference point and the approximate view reference point; - determine the first surface that has: o a regression of the average sphere value between at least a portion of the distant view area and at least a portion of the approximate view area; and the fourth one derived from the normalized altitude value of less than 5.0.10'5 at any point in the central portion; - flatten or shape the first surface.
[00018] The invention additionally relates to a method for manufacturing a semi-finished lens model which comprises the steps of: - defining a first surface and a second unfinished surface, the first surface having an altitude at each point, a sphere value average and a cylinder value; - define a zone of distant vision that has a reference point of distant vision, a zone of approximate views that has a reference point of approximate vision, a main meridian and a central point of the first surface that includes a portion of the main meridian, the distant view reference point and the approximate view reference point; - determine the first surface that has: o a regression of the average sphere value between at least a portion of the distant view area and at least a portion of the approximate view area; and o a normalized sphere gradient value of less than 7.50.101 mm1 at any point in the central portion; and o a normalized cylinder gradient value of less than 1.45 mm1 at any point in the central portion; - flatten or shape the first surface.
[00019] The invention additionally relates to a method for manufacturing a progressive ophthalmic lens comprising the steps of: - providing data relating to a user, - selecting a semi-finished lens model according to the invention; - perform an optical optimization of the lens based on the data relating to the user and the data relating to the first regressive surface of the model, - supply the selected semi-finished lens model and flatten or shape the model's unfinished surface according to the result of the optical optimization.
[00020] The invention additionally relates to a method for manufacturing a progressive ophthalmic lens that comprises the steps of: - providing data relating to a user, - defining the far-sighted area that has a far-sighted reference point, an area approximate view that has a close view reference point, a main meridian, - define a first lens surface that has: o a regression of the average sphere value between at least a portion of the distant view area and at least a portion the area of approximate views; o a normalized sphere gradient value of less than 7.50.101 mm1 at any point on a central portion of the lens that includes a portion of the main meridian, the distant view reference point and the approximate view reference point; o a normalized cylinder gradient value of less than 1.45 mm1 at any point in the central portion of the lens; - perform an optical optimization of the lens based on the data relating to the user and the data relating to the first surface of the lens; - determine a second lens surface according to the result of the optical optimization; - flatten or shape the first and second surfaces.
[00021] The invention also relates to a method for making a progressive ophthalmic lens that comprises the steps of: - providing data relating to a user, - defining the far-sighted zone that has a far-sighted reference point, a zone approximate view that has a close view reference point, a main meridian, - define a first lens surface that has: o a regression of the average sphere value between at least a portion of the distant view area and at least a portion the area of approximate views; o a fourth derivative from the normalized altitude value of less than 5.0.10 5 at any point on a central portion of the lens that includes a portion of the main meridian, the distant view reference point and the view reference point approximate; - perform an optical optimization of the lens based on the data relating to the user and the data relating to the first surface of the lens; - determine a second lens surface according to the result of the optical optimization; - flatten or shape the first and second surfaces.
[00022] The invention also relates to a set of devices for making a progressive ophthalmic lens and / or a semi-finished lens model, in which the devices are adapted to perform steps of the method according to the invention.
[00023] The invention additionally relates to a computer program product that comprises one or more stored instruction sequences that is accessible to a processor and that, when executed by the processor, causes the processor to carry out the steps of the method accordingly with the invention. The invention also relates to a computer-readable medium that carries out one or more instruction sequences of the computer program product of the invention.
[00024] The distant view reference point (resp. The approximate view reference point) can be, for example, a control point. More generally, the distant view reference point (resp. The close view reference point) can be any other point on the front surface in the distant view area (resp. In the close view area).
[00025] Since ball and cylinder variations (also called sphere and cylinder gradients) and / or ball and cylinder acceleration variations are controlled on the front surface of the progressive ophthalmic lens according to the invention, it is possible to guarantee improved technical feasibility of machining with a digital flattening machine on the rear surface while maintaining the optical quality of the lens.
[00026] The additional attributes and advantages of the invention will appear from the following description of embodiments of the invention, given as non-limiting examples, with reference to the attached drawings listed below in this document. BRIEF DESCRIPTION OF THE DRAWINGS - Figures 1 to 5 are a mean sphere graph along the meridian, a mean sphere map, a cylinder map, a sphere gradient map and a cylinder gradient map, respectively, of a front surface of a semi-finished lens model, according to a first comparative example; - Figures 6 to 10 are a mean sphere graph along the meridian, a mean sphere map, a cylinder map, a sphere gradient map and a cylinder gradient map, respectively, of a front surface of a semi-finished lens model, according to a second comparative example; - Figures 11 to 15 are a mean sphere graph along the meridian, a mean sphere map, a cylinder map, a sphere gradient map and a cylinder gradient map, respectively, of a front surface of a semi-finished lens model, according to a first embodiment of the invention; - Figures 16 to 20 are an average sphere graph along the meridian, an average sphere map, a cylinder map, a sphere gradient map and a cylinder gradient map, respectively, of a front surface of a semi-finished lens model, according to a second embodiment of the invention; - Figures 21 to 25 are a mean sphere graph along the meridian, a mean sphere map, a cylinder map, a sphere gradient map and a cylinder gradient map, respectively, of a front surface of a semi-finished lens model, according to a third embodiment of the invention; - Figures 26 to 40 provide optical analyzes of the nominal performances of the considered lenses; - Figures 41 to 45 are an average sphere graph along the meridian, an average sphere map, a cylinder map, a sphere gradient map and a cylinder gradient map, respectively, of a rear surface when the semi-finished lens model of Figures 1 to 5 is used; - Figures 46 to 50 are an average sphere graph along the meridian, an average sphere map, a cylinder map, a sphere gradient map and a cylinder gradient map, respectively, of a rear surface when the semi-finished lens model of Figures 6 to 10 is used; - Figures 51 to 55 are a mean sphere graph along the meridian, a mean sphere map, a cylinder map, a sphere gradient map and a cylinder gradient map, respectively, of a rear surface when the semi-finished lens model of Figures 11 to 15 is used; - Figures 56 to 60 are an average sphere graph along the meridian, an average sphere map, a cylinder map, a sphere gradient map and a cylinder gradient map, respectively, of a rear surface when the semi-finished lens model of Figures 16 to 20 is used; - Figures 61 to 65 are a mean sphere graph along the meridian, a mean sphere map, a cylinder map, a sphere gradient map and a cylinder gradient map, respectively, of a rear surface when the semi-finished lens model of Figures 21 to 25 is used; Figures 66 to 68 provide an optical analysis of the performance of the lens according to the first comparative example when the positioning defect occurs; Figures 69 to 71 provide optical analysis of the performance of the lens according to the third embodiment of the invention when the positioning defect occurs; - Figures 72 to 77 compared the optical analysis of nominal performances and the optical analysis of performances when positioning defects occur; - Figure 78 is a graph showing the maximum deviation from the nominal performances for each lens considered; - Figures 79 and 80 show the defined reference in relation to the micro marks, for a surface that bears micro marks and for a surface that does not bear the micro marks, respectively; Figure 81 is a schematic illustration of a progressive multifocal lens; Figure 82 is a perspective view of a lens model to be positioned on a blocker; Figure 83 is a flow chart of the steps of a method of manufacturing a lens according to the invention.
[00027] It can be seen that the elements in the figures are illustrated for simplicity and clarity and were not necessarily drawn to scale. For example, the dimensions of some of the elements in the Figures can be exaggerated in relation to the other elements to help improve the understanding of the modalities of the present invention. DETAILED DESCRIPTION OF PREFERENTIAL MODALITIES
[00028] A progressive lens comprises two aspherical surfaces not rotationally symmetrical to, for example, however, without limitation, progressive surface, regressive surface, toric or aoric surfaces.
[00029] As is known, each point on an aspheric surface has an altitude of z. For each point on the surface, a minimum CURVmin curvature is given by the formula:
where Rmax is the maximum local radius of curvature, expressed in meters and CURVmin is expressed in diopters.
[00030] Similarly, a maximum CURVmax curvature can be defined at any point on an aspherical surface by the formula:
where Rmin is the minimum local radius of curvature, expressed in meters and CURVmax is expressed in diopters.
[00031] It can be seen that when the surface is spherically located, the minimum local radius of curvature Rmin and the maximum local radius of curvature Rmax are the same and, consequently, the minimum and maximum curvature CURVmin and CURVmax are also identical.
[00032] From these expressions of the minimum and maximum curvatures CURVmin and CURVmax, the minimum and maximum spheres classified SPHmin and SPHmax can be deduced according to the type of surface considered.
[00033] When the surface considered is the objective lateral surface - also called the frontal surface, the expressions are as follows:
where n is the index of the lens constituent material.
[00034] If the surface considered is a lateral eyeball surface - also called the rear surface, the expressions are as follows:
where n is the index of the lens constituent material.
[00035] As is known, an average SPH average sphere at any point on an aspheric surface can also be defined by the formula:
- A CYL cylinder is also defined by the formula

[00036] The characteristics of any complex face of the lens can be expressed by means of local medium spheres and cylinders. A surface can be considered as aspherical in a localized way when the cylinder is at least 0.25 diopters.
[00037] Whenever a lens is characterized in reference to one of its aspherical surfaces, a reference is defined in relation to the micromarkings as shown in figures 79 and 80, for a surface that bears micromarkings and for a surface that does not bear the micromarkings respectively .
[00038] Progressive lenses comprise micro markings that were considered mandatory by a harmonized ISO 8990-2 standard. Temporary markings can also be applied to the surface of the lens, indicating positions of control points on the lens, such as a control point for distant vision, a control point for close-up vision, a prism reference point and a cross fit by example. If the temporary markings are absent or have been erased, it is always possible for a knowledgeable person to position the control points on the lens using an assembly graphic and permanent micro marks. The lens manufacturer must guarantee prescription at checkpoints.
[00039] Micro-markings also make it possible to set the frame for both surfaces of the lens.
[00040] Figure 79 shows the reference for the surface that bears the micro marks. The center of the surface (x = 0, y = 0) is the point on the surface at which the normal N to the surface intersects the center of the segment that connects the two micromarks. MG is the unitary collinear vector defined by the two micromarkings. The vector Z of the referential is equal to the unit normal (Z = N); the vector Y of the referential is equal to the vector product of Z by MG; the vector X of the referential is equal to the vector product of Y by Z. {X, Y, Z} thus forming a direct orthonormal trihedral. The center of the frame is the center of the surface x = 0 mm, y = 0 mm. The X geometric axis is the horizontal geometric axis and the Y geometric axis is the vertical geometric axis.
[00041] Figure 80 shows the reference for the surface opposite the surface that bears the micro-markings. The center of this second surface (x = 0, y = 0) is the point at which the normal N that intersects the center of the segment connecting two micro-markings on the first surface intersects the second surface. The second surface frame is constructed in the same way as the first surface frame, that is, the vector Z is equal to the unitary normal of the second surface; the vector Y is equal to the product vector of Z by MG; the vector X is equal to the vector product of Y by Z. As for the first surface, the geometric axis X is the horizontal geometric axis and the geometric axis Y is the vertical geometric axis. The center of the surface reference is also x = 0 mm, y = 0 mm.
[00042] Similarly, in a semi-finished lens model, the ISO 10322-2 standard requires micro-markings to be applied. The center of the aspherical surface of a semi-finished lens model can therefore be determined as well as a reference as described above.
[00043] In addition, a progressive multifocal lens can also be defined by optical characteristics, taking into account the situation of the person wearing the lenses. Reference may be made to the documents of EP-A-0 927 377, EP-A-0 990 939 or WO-A-2010/100528 which define, for example, a lens with optical characteristics.
[00044] As you know, it is possible to define an optical power of sight and astigmatism, in each direction of view.
[00045] Possible definitions of optical power and astigmatism of the lens, under the conditions of use, can be calculated as explained in the article by B. Bourdoncle et al., Entitled "Ray tracing through progressive ophthalmic lens", 1990 International Design Conference of Lens, DT Moore ed., Proc. Soc. Photo. Opt. Instrum. Eng. The conditions of use can be calculated from a radius tracing program, for a given lens. In addition, optical power and astigmatism can be calculated so that the prescription is met for a user who wears his glasses under the conditions of use. Optical power and astigmatism can also be measured using a front-focus meter.
[00046] Values in optical terms can be expressed for looking directions. The directions of looking are generally given by their degree of lowering and azimuth in a frame whose origin is the center of the eye's rotation. When the lens is mounted on the front of the eye, a point called a cross fit is placed before the pupil or before the eye's pivot center Q 'of the eye for a primary look direction. The primary look direction corresponds to the situation where a user is looking straight ahead. In the chosen frame, the crosshair thus corresponds to a lowering angle α of 0o and an azimuth angle β of 0o whatever the surface of the lens on which the crosshair is positioned - rear surface or front surface.
[00047] In the rest of the description, terms such as "top", "bottom", "horizontal", "vertical", "above", "below", or other words that indicate the relative position can be used. These terms must be understood in the conditions of use of the lens. Notably, the "upper" part of the lens corresponds to a negative angle of lowering α <0 ° and the "lower" part of the lens corresponds to a positive angle of lowering α> 0 °. Similarly, the "upper" part of the lens surface - or a semi-finished lens model - corresponds to a positive value along the Y axis and preferably to a value along the Y axis above the y_value on the cross fitting and the "bottom" part of a lens surface - or a semi-finished lens model - corresponds to a negative value along the Y axis in the frame as defined above in relation to Figures 79 and 80 and preferably a value along the Y geometric axis lower than the y_value on the docking cross.
[00048] The areas of visual field seen through a lens are schematically illustrated in figure 81. The lens comprises a wide viewing area 26 located at the top of the lens, an approximate viewing area 28 located at the bottom of the lens and a intermediate zone 30 located at the bottom of the lens between the remote viewing zone 26 and the approximate viewing zone 28. The lens also has a main meridian 32 that passes through the three zones and defines a nasal side and a temporal side. Typically, the far view zone 26 includes a PV far view control point and the close view zone 28 includes a NV close view control point. When a lens surface is considered, the wide viewing area and the close viewing area can be defined as the projection of the zones defined above on the surface. When the surface of a lens or a semi-finished model of a lens is considered, the zone of far view, respectively, the zone of close view, can be defined as the zones that contribute to the zone of far field of view, respectively, the zone field of view when the lens is used.
[00049] For the purpose of the invention, the meridian line 32 of a progressive lens is defined as follows: for each lowering of the view from an angle α = cn between the look direction corresponding to the fitting cross and a look direction which is in the approximate vision zone, the direction of looking (ai, βi) is examined for which the local residual astigmatism is minimal. In this way, all the viewing directions defined in this way form the meridian line of the ergorama ocular lens system. The lens meridian line represents the location of a user's average looking directions when the user is looking from distant to close view. The meridian line 32 of a lens surface can be defined as follows: each look direction (α, β) that belongs to the optical lens meridian line intersects the surface at a point (x, y). The meridian line of the surface is the set of points corresponding to the viewing directions of the lens meridian line. The meridian line 32 of an aspherical surface of the lens - or an aspheric surface of a semi-finished lens model - can also be defined as follows: for each line y between the center of the surface reference (x = 0 mm; y = 0 mm) and the bottom of the surface, the point (x, y) is examined for which the local cylinder is minimal.
[00050] As shown in figure 81, meridian 32 separates the lens into a nasal area and a temporal area. As expected, the nasal area is the area of the lens that is between the meridian and the user's nose while the temporal area is the area that is between the meridian and the user's temple.
[00051] The invention is based on a study of the depositor of the distortion. Notably, the depositor established that a frontal regressive surface increases the optical distortion in peripheral vision in the final lens. The depositor noted that the more regressive the front surface was, the better the distortion was compensated.
[00052] By "regressive surface" is represented a continuous aspheric surface that has a zone of distant vision, a zone of approximate vision and a zone of decreasing average sphere value that connects zones of distant vision and approximate vision. By "progressive surface" is represented a continuous aspherical surface that has a zone of distant vision, a zone of approximate vision and a zone of increasing mean sphere value that connects the zones of distant vision and approximate vision.
[00053] The "addition of a surface" can be defined as the variation of the mean sphere between the approximate vision reference point (NV) that belongs to the approximate vision zone and the distant vision reference point (FV) that belongs to to the far-sighted area. Reference points can be, for example, but without limitation, control points. The addition of the surface can be expressed as: Addsurface = Medium SPH (NV) —SPH medium (FV); If Addsurface> 0, the surface is a progressive surface; If Addsurface <0, the surface is a regressive surface.
[00054] When the distant view reference point and the approximate view reference point are selected in the distant and approximate vision zones, so that the absolute value of the surface addition is maximized, that addition value will be called the value maximum surface addition.
[00055] The regressive surface of the lens model according to the invention has an average sphere value in at least a portion of the distant view zone which is greater than the average sphere value in at least a portion of the view zone approximate.
[00056] However, when the front surface is regressive, that is, the average sphere value in at least a portion of the distance viewing area is greater than the average sphere value in at least a portion of the approximate viewing area. , the rear surface needs to have an even greater addition to obtain a positive power addition on the final lens. For a progressive lens suitable for a prescription of 2 prescribed addition diopters, if the front surface has a negative addition of about 3 diopters for example, the rear surface must have a positive addition of about 5 diopters to ensure an added power positive of about 2 diopters the lens.
[00057] Such a strong variation of sphere on the rear surface will also induce a strong variation of cylinder. Strong ball and cylinder variations increase complexity when machining the surface.
[00058] In fact, when machining a lens surface, a grinding step is first carried out in which the material is removed from the lens surface to bring the surface as close as possible to the requested geometry to obtain the desired surface characteristics. Then a polishing step is carried out to obtain a transparent surface while preserving the geometry obtained after grinding.
[00059] During the grinding step, the ball and cylinder gradients will impact the acceleration of the machining equipment. The stronger the gradients are, the more intense is the acceleration, which can cause the degradation of the surface obtained after grinding and, therefore, the degradation of optical performance.
[00060] During the polishing step, gradients tend to be filtered. Whenever the values of gradients vary sharply, the polishing step will slow down this variation, which can cause the degradation of the surface obtained after polishing, noticeably along the meridian line.
[00061] In addition, high sphere and cylinder gradients and strong gradient variations will make surfaces very sensitive to positioning relative to each other. Positioning errors between both surfaces are caused by a manufacturing process, for example, when the lens model is positioned in a blocker of a digital planing machine to create the second surface of the unfinished surface.
[00062] Figure 82 illustrates the positioning of a lens model 10 in a reference frame of a lens locking device 20 of a digital planing machine.
[00063] The reference frame of the lens model 10 in the blocker 20 can be defined by: - translations Tx θ TY in a horizontal plane XY with values Tx, TY, defining the deviation from the center point O of the lens model along the X and Y directions, respectively, in the horizontal plane; - Tz translation along a vertical Z axis, - Rz orientation of the lens model around the vertical Z axis, - RY orientation of the lens model around the horizontal Y geometric axis, - Rx orientation of the lens model in around the horizontal geometric axis X.
[00064] An error in the positioning of the lens model, that is, a translation and / or rotation, will cause the flatness of a second surface to deviate from the first surface and the optical performances of the final lens will not be compatible with the nominal performances (nominal performances which are the theoretical performances of the lens considering no manufacturing error). A method of compensating for the positioning error when manufacturing the lens is described in patent document No. WO-A- 2010/072749. However, whenever a surface has a rigid design, that is, high sphere and cylinder gradients and strong gradient variations, even a slight positioning error will result in greater optical divergence between the optical performance of the lens and the nominal performance.
[00065] Therefore, the invention proposes a semi-finished lens model with a regressive surface that has a very soft design. Such a mild design will ensure that the gradients do not change too drastically. In this way, when the model's unfinished surface will be machined to fulfill a local optical design and the user's prescription, the values and variations of sphere and cylinder gradients will also be better controlled.
[00066] The invention also proposes a progressive lens with a frontal regressive surface that has a very soft design. The following is a detailed description of a first regressive surface of a semi-finished lens model. In addition, the following description could be given in similar terms for the front regressive surface of a progressive lens.
[00067] As explained earlier, an aspherical surface can be defined in a localized way by the cylinder and the middle sphere.
[00068] Sphere and cylinder gradients can also be defined. The gradient is conventionally defined as the vector whose coordinates along this geometric axis are respectively equal to the partial derivatives of the middle sphere (respectively cylinder) along this geometric axis and, although this is an inappropriate use of language, the norm of gradient vector is called the gradient, that is:

[00069] The sphere and cylinder gradients are representative of local variations in the sphere and cylinder. The sphere gradient is smaller as the surface addition is low or slow, that is, it is not sudden. However, a progressive or regressive surface necessarily has a non-zero sphere gradient.
[00070] The cylinder is representative of how much the local surface deviates from a spherical surface. Sphere variations cause the need for cylinder variations and the cylinder cannot be zero across the lens surface.
[00071] A fourth derivative in relation to altitude z can also be defined at each point on the aspheric surface. Such a fourth derivative can be expressed as follows:

[00072] The fourth derivative D4 is representative of how quickly the gradient values change, that is, the acceleration of the sphere and cylinder variations.
[00073] The invention proposes to control the value of the fourth derivative D4 on the first surface of the lens model. Such control will thus contribute to significantly reduce the possible degradation of the surface during the polishing step when machining the second surface of the lens and also when machining that first surface if the digital flattening technique is used as explained in more detail below.
[00074] This quantity is controlled, at least in a central portion of the first surface of the lens model. This central portion includes a portion of the main meridian, a reference point in the far view area and a reference point in the approximate view area. The reference points can be the control points defined above, but any other reference points can be chosen. For example, the D4 value is controlled within a 40 mm diameter circle - that is, within a 20 mm radius around the center of the lens model; this takes into account regions excluded at the edge of a lens that are used infrequently by the lens wearer. The optical performances of the lens are typically considered within a central portion for viewing directions comprised within a cone of +/- 400 aperture centered at the center of the eye's rotation. The invention also proposes to normalize the value of the fourth derivative, to obtain an amount that is not a function of the addition of the surface. The normalization factor involves the addition value.
[00075] Notably, the invention proposes to adjust a limit value to the fourth derivative D4 when determining the regressive surface of the semi-finished lens model. More specifically, the normalized value of the fourth derivative D4 is limited to 5.0.10 5 mm'2.dioptr''1 at least in the central portion of the lens model and is preferably limited to 3.5.10'5mm'2.dioptr''1 of model.
[00076] The maximum value of the fourth derivative D4 that is located along the meridian line of the aspherical surface of the lens model, the normalized value of the fourth derivative D4 can be limited to 5.0.10 5 mm'2.dioptr''1 - and more preferably limited to 3.5.10-5 mnr2.dioptria'1 - in a portion of the lens model delimited by the +/- 5 mm meridian line. However, the value of the fourth derivative D4 cannot be null in that central portion and a minimum value of 1.0.10 6 mirP.dioptria'1 should be expected. This normalization factor is equal to the maximum value of the addition of the surface.
[00077] The invention also proposes to control the value of the sphere and cylinder gradients on the first surface of the lens model. Such control will thus contribute to significantly reduce the possible degradation of the surface during the grinding step when machining the second surface of the lens and also when machining that first surface if the digital flattening technique is used.
[00078] The sphere and cylinder gradients are controlled, at least in a central portion of the first surface of the lens model. For example, sphere and cylinder gradients are controlled within the 40 mm diameter circle defined above. The limit values of sphere and cylinder gradients can be normalized to obtain an amount that is not a function of the addition of the surface.
[00079] Notably, the invention proposes to adjust a limit value to the sphere gradient when determining the regressive surface of the semi-finished lens model. More specifically, the normalized value of the sphere gradient is limited to 7.50.10'1 mm1 at least in the central portion of the lens model and is preferably limited to 6.50.101 mm1 in the central portion of the model. However, the value of the sphere gradient cannot be null in that central portion and a minimum value of 1.0.10’2 mm1 should be expected. This normalization factor is equal to the maximum value of the addition of the surface.
[00080] In addition, the invention also proposes to adjust a limit value to the cylinder gradient when determining the regressive surface of the semi-finished lens model. More specifically, the normalized value of the cylinder gradient is limited to 1.45 mm1 at least in the central portion of the lens model and, preferably, it is limited to 1.25 mm1 in the central portion of the model. However, the value of the sphere gradient cannot be null in that central portion and a minimum value of 1.0.10’2 mm1 should be expected. This normalization factor is equal to the maximum value of the addition of the surface.
[00081] Next, an orthonormal coordinate system can be used in which the geometric axis x corresponds to the horizontal geometric axis of the lens and the geometric axis y to the vertical geometric axis; the center O of the reference frame is the geometric center of the lens model surface as defined in relation to figures 79 and 80. In the description that follows, the geometric axes are graduated in millimeters.
[00082] FIG. 1 to 25 are illustrations of surfaces of semi-finished lens models, that is, front surfaces of the final lenses. FIG. 1 to 5 and 6 to 10 are illustrations of surfaces according to the comparative examples outside the scope of the invention and FIG. 11 to 15 and 16 to 20 and 21 to 25 are illustrations of surfaces according to three examples of the invention. In the following, reference will be made to Lens 1 and Lens 2 for the two comparative examples and reference will be made to Lens 3, Lens 4 and Lens 5 for the three examples of the invention.
[00083] The five examples are given for a lens for a user whose prescription would be optical power prescribed in 0 diopter distance vision, astigmatism prescribed in 0 diopter distance vision and prescribed addition of 2.5 diopters for 60 half-finished lens models mm in diameter. The average sphere value at the control point for distant vision is 4.72 diopters.
[00084] FIG. 1 is a graph of variation of the average sphere relative to the average sphere value of the control point of view distant along the meridian for the surface of the first comparative example. The geometric axis X is graduated in diopters and the values of geometric axis y in mm. The remote view control point has a geometry axis x value of 0 mm, a geometry axis y value of 8 mm on the surface and has a sphere of 4.72 diopters and a cylinder of 0.02 diopters. The close view control point has a geometry axis x value of 3 mm, a geometry axis y value of -14 mm on the surface and has a sphere of 2.20 diopters and a cylinder of 0.04 diopters. The nominal surface addition is -2.52 diopters, calculated as the difference between the mean spheres at the control points.
[00085] FIG. 6 is a graph of variation of the mean sphere relative to the mean sphere value of the remote control point of view along the meridian for the surface of the second comparative example. The geometric axis X is graduated in diopters and the values of geometric axis y in mm. The remote view control point has a geometry axis x value of 0 mm, a geometry axis y value of 8 mm on the surface and has a sphere of 4.72 diopters and a cylinder of 0.02 diopters. The close view control point has a geometric axis x value of 3 mm, a geometric axis y value of -14 mm on the surface and has a sphere of 2.20 diopters and a cylinder of 0.06 diopters. The nominal surface addition is -2.52 diopters, calculated as the difference between the mean spheres at the control points.
[00086] FIG. 11 is an average sphere graph along the meridian towards the surface according to a first example of the invention. The geometric axis X is graduated in diopters and the values of geometric axis y in mm. The remote view control point has a geometry axis x value of 0 mm, a geometry axis y value of 8 mm on the surface and has a sphere of 4.72 diopters and a cylinder of 0.07 diopters. The close view control point has a geometry axis x value of 3 mm, a geometry axis y value of -14 mm on the surface and has a sphere of 2.20 diopters and a cylinder of 0.08 diopters. The nominal surface addition is -2.51 diopters, calculated as the difference between the average spheres at the control points.
[00087] FIG. 16 is a graph of average sphere along the meridian towards the surface according to a second example of the invention. The geometric axis X is graduated in diopters and the values of geometric axis y in mm. The remote view control point has a geometry axis x value of 0 mm, a geometry axis y value of 8 mm on the surface and has a sphere of 4.72 diopters and a cylinder of 0.07 diopters. The close view control point has a geometry axis x value of 3 mm, a geometry axis y value of -14 mm on the surface and has a sphere of 2.20 diopters and a cylinder of 0.08 diopters. The nominal surface addition is -2.51 diopters, calculated as the difference between the average spheres at the control points.
[00088] FIG. 21 is a mean sphere graph along the meridian towards the surface according to a third example of the invention. The geometric axis X is graduated in diopters and the values of geometric axis y in mm. The remote view control point has a geometry axis x value of 0 mm, a geometry axis y value of 8 mm on the surface and has a sphere of 4.71 diopters and a cylinder of 0.10 diopters. The close view control point has a geometric axis x value of 3 mm, a geometric axis y value of -14 mm on the surface and has a 2.21 diopter sphere and a 0.10 diopter cylinder. The nominal surface addition is -2.50 diopters, calculated as the difference between the average spheres at the control points.
[00089] It can be seen from the comparison of FIG. 1 and 6 to FIG. 11, 16 and 21 that the regression value is approximately the same for all surfaces, but the variations in sphere in proximity to the control points are less strong on the surfaces according to the invention. More specifically, the marked variation of sphere and cylinder located close to the control points was softened on the surfaces according to the invention, notably for the example of Lens 5. The maximum value of the fourth derivative D4 defined above is representative of these marked variations ball and cylinder. D4 is directly linked to the acceleration of the ball and cylinder. When adjusting a threshold value for D4 on at least a central portion of the surface that includes a portion of the meridian, 0 approximate vision control point and 0 distant vision control point, the areas of the meridian where the accelerations of the middle sphere the strongest are smoothed.
[00090] FIG. 2, 7, 12, 17 and 22 are maps showing the variation of the mean sphere relative to the mean sphere value of the far-sight control point for the front surfaces of Lens 1, Lens 2, Lens 3, Lens 4 and Lens 5 respectively. These maps show the projection of the surface on the plane (x, y); the reference frame (x, y) defined above as well as the main meridian will be recognized. Control points for distant and close view have respective coordinates of (0; 8) and (3; -14).
[00091] In FIG. 2, 7, 12, 17 and 22, the isosphere lines, in other words, the lines joining points that have the same mean sphere value can be seen. It can be seen that the sphere gradients are much smaller, that is, the isosphere lines are more separated, on the surfaces according to the invention in comparison to the surfaces of the comparative examples.
[00092] FIG. 3, 8, 13, 18 and 23 are cylinder maps for the front surfaces of Lens 1, Lens 2, Lens 3, Lens 4 and Lens 5 respectively; the same graphic conventions and indications as those of FIG. 2, 7, 12, 17 and 22 are used, which simply show the cylinder in place of the sphere in this drawing. It can be seen that the cylinder gradients are much smaller, that is, the isocylinder lines are more separated, on the surfaces according to the invention in comparison to the surfaces of the comparative examples.
[00093] FIG. 4, 9, 14, 19 and 24 are sphere gradient maps for the front surfaces of Lens 1, Lens 2, Lens 3, Lens 4 and Lens 5 respectively. These maps confirm that the sphere gradients of the surfaces according to the invention are much smaller than the sphere gradients of surfaces of comparative examples that have a rigid design. Remarkably, the normalized sphere gradient to the nominal surface addition is less than 7.50.10'1 mm1 at any point in the 40 mm circle centered at the center point O for the surfaces of the invention - note that the maps show the non-normalized values of sphere gradients.
[00094] FIG. 5, 10, 15, 20 and 25 are cylinder gradient maps for the front surfaces of Lens 1, Lens 2, Lens 3, Lens 4 and Lens 5 respectively. These maps confirm that the surface cylinder gradients according to the invention are much smaller than the surface cylinder gradients of comparative examples that have a rigid design. Notably, the cylinder gradient is less than 1.45 mm1 at any point in the 40 mm circle centered at the center point O for the surfaces of the invention - note that the maps show the non-normalized values of sphere gradients .
[00095] It can also be seen that the isogradient lines in FIG. 14 to 15, 19 to 20, 24 to 25 are much more widely spaced, less close to each other, in the central portion of the lens as compared to FIG. 4 to 5 and 9 to 10. The variation of gradients on the front surfaces of Lens 3, Lens 4 and Lens 5 is much less than the variation of gradients on the front surface of Lens 1 and Lens 2. This indicates that the fourth derivative D4 it has low values on the surfaces of the invention as compared to the surfaces of the comparative examples.
[00096] In addition, the maximum value of D4 in the remote viewing zone is located close to the remote viewing control point, that is, at least 4 mm above the center of the surface along the y axis and preferably at least 8 mm above the center of the surface along the y-axis. In addition, the maximum value of D4 in the approximate vision zone is located below the approximate vision control point, that is, at least 8 mm below the center of the surface and preferably at least 14 mm below the center of the surface. As a consequence, the gradient variations will be smaller in the central portion of the first surface of the semi-finished lens model. In addition, the maximum D4 value of the calculated rear surface will also be less and the flattening will be more accurate.
[00097] Table I below summarizes the normalized maximum values of fourth derivative D4, 0 sphere gradient and 0 cylinder gradient for the front surfaces of the considered lenses.

[00098] FIG. 26 to 40 are optical analyzes of the nominal performance of the considered lenses. Nominal performances are defined according to the best selected commitments that result from the distribution of optical failures in the lens. A target optical function is then defined to be used during optical optimization when defining the surface characteristics of the lens. The manufactured lens finally obtained may have optical performances that deviate slightly from the nominal performances, due, notably, to the machining limitations and positioning defects.
[00099] FIG. 26, 29, 32, 35, 38 represent nominal power along the main meridian for Lenses 1, Lens 2, Lens 3, Lens 4 and Lens 5 respectively. The optical addition is 2.69 diopters for Lens 1 and Lens 2; 2.67 diopters for Lens 3; 2.66 diopters for Lens 4 and Lens 5, with no power at the control point of far vision. It is immediately evident that the optical performances along the meridian are the same for all lenses.
[000100] FIG. 27, 30, 33, 36 and 39 show the rated power perceived by the user with Lenses 1, Lens 2, Lens 3, Lens 4 and Lens 5 respectively. Figures 28, 31,34, 37 and 40 show the resulting astigmatism for Lenses 1, Lens 2, Lens 3, Lens 4 and Lens 5 respectively. It is immediately evident that the optical performances are substantially the same for all lenses.
[000101] The use of a semi-finished lens model according to the invention allows for easier lens fabrication by maintaining the optical performance of the lens as it will now be explained.
[000102] FIG. 41 to 65 are illustrations of a second lens surface manufactured from the lens models of FIG. 1 to 25, that is, the rear surfaces of the lenses considered Lens 1, Lens 2, Lens 3, Lens 4 and Lens 5.
[000103] FIG. 41, 46, 51, 56 and 61 are graphs of mean sphere variation along the meridian for the rear surfaces of Lens 1, Lens 2, Lens 3, Lens 4 and Lens 5 respectively. The nominal surface power progression is 4.76 diopters for Lens 1 and Lens 2, 4.77 diopters for Lens 3, Lens 4 and Lens 5, calculated as the difference between the mean spheres at the control points.
[000104] It can be seen from the comparison of FIG. 41 and 46 to FIG. 51, 56 and 61 that the marked variations of ball and cylinder at the control points are milder, notably in FIG. 56 and 61. The manufacture of the second surface will therefore be easier.
[000105] FIG. 42, 47, 52, 57 and 62 are maps showing the variation of the mean sphere relative to the mean sphere value of the far-sight control point for the rear surfaces of Lens 1, Lens 2, Lens 3, Lens 4 and Lens 5 respectively. FIG. 43, 48, 53, 58 and 63 are maps showing the cylinder for the rear surfaces of Lens 1, Lens 2, Lens 3, Lens 4 and Lens 5 respectively. FIG. 44, 49, 54, 59 and 64 are maps showing the sphere gradients for the rear surfaces of Lens 1, Lens 2, Lens 3, Lens 4 and Lens 5 respectively and FIG. 45, 50, 55, 60 and 65 are maps showing cylinder gradients for the rear surfaces of Lens 1, Lens 2, Lens 3, Lens 4 and Lens 5 respectively.
[000106] It can be seen that when a lens model that has a first surface according to the invention is used, the sphere and cylinder gradients are smaller on the second surface as compared to using a lens model that has a first surface according to the comparative examples. It can also be seen that the isogradient lines in FIG. 54 to 55, 59 to 60, 64 to 65 are more widely spaced, less close to each other, in the central portion of the lens as compared to FIG. 44 to 45 and 49 to 50. This indicates that the fourth derivative D4 has lower values on the rear surfaces of lenses that have a front surface according to the invention as compared to the rear surfaces of lenses that have a front surface according to the examples comparative.
[000107] Table II below summarizes the maximum normalized values of the fourth derivative D4, sphere gradient and cylinder gradient for the rear surfaces of the considered lenses.

[000108] Due to the control of ball and cylinder gradients on the front surface, the ball and cylinder gradients can be reduced on the rear surface and the accelerations of the digital flattening tool will be limited during flattening of the lens surface. In this way, the surface grinding will be more accurate.
[000109] Due to the control of derived room on the front surface, sharp variations in gradients will also be avoided when flattening the rear lens surface. In this way, the polishing of the rear surface will be less affected.
[000110] Therefore, the use of a semi-finished model according to the invention, with a soft design and controlled values of derived room, makes it easier to manufacture the lens and further increases the optical quality of the lens obtained after flattening the second surface.
[000111] In fact, as mentioned above in relation to FIG. 26 to 40, the nominal optical performances are substantially the same for all lenses. In addition, the lenses of the invention are more tolerant of positioning defects during manufacture.
[000112] FIG. 66 to 68 are optical performances of Lens 1 with simulated positioning defects of Tx = + θ, 2 mm, TY = +0.2 mm and Rz = + 0.5 ° for the front surface and of Tx = -0.2 mm, TY = -0.2 mm and Rz = -0.5 ° for the rear surface. FIG. 69 to 71 are optical performances of Lens 5 with the same simulated positioning defects. FIG. 72 to 74 are overlays of nominal optical performances and simulated optical performances with positioning defects for Lens 1, that is, overlap of FIG. 26 to 28 and FIG. 66 to 68. FIG. 75 to 77 are overlays of nominal optical performances and simulated optical performances with positioning defects for Lens 5, that is, the overlap of FIG. 38 to 40 and FIG. 69 to 71. FIG. 78 is a graph that shows the maximum deviation between nominal performances and simulated optical performances with positioning defects for each lens considered. The impact of positioning defects was evaluated on a central portion of the lens and notably for the directions of view -40 ° <to <40 ° and - 40 ° <β <40 °. To provide the graph of FIG. 78, the deviation between the nominal power / resultant astigmatism and the simulated power / resultant astigmatism was calculated for each direction of view in the central portion defined above for each lens; then the maximum deviation was assessed from among the deviation values for all directions of view in the central portion of the lens. It is immediately evident that lenses that have a frontal regressive surface according to the invention have less deviation from the nominal performances than lenses that have a frontal regressive surface according to comparative examples even though all positioning defects have been simulated. In this way, lenses manufactured from a lens model according to the invention will have improved optical quality once manufactured.
[000113] The maximum values adjusted for the sphere gradients, cylinder and derived fourth gradients when defining the front regressive surface of the lens ensure that the rear surface can be manufactured without creating many defects - during grinding and polishing as explained above - but they also ensure that small positioning defects impact only slightly on the optical performance of the manufactured lens - The user's acuity is not really affected.
[000114] Several studies have been done to analyze a user's visual acuity in relation to the resulting potency and astigmatism defects; the notable publication "Influence of combined power error and astigmatism on visual acuity" in Ophthalmic and Visual Optics Technical Digest, (Optical Society of America, Washington, DC, 1995), Vol, 1, pages 151 to 154) [Catherine FAUQUIER, Thierry BONNIN, Christian MIEGE, Eric ROLAND] Essilor International. It is considered that an average power deviation of 0.31 diopters combined with an astigmatism deviation resulting from 0.39 diopters (Lenses 1) from the nominal performances causes a reduction in acuity of more than 33% that will be substantially perceived by most users, while an average power deviation of 0.22 diopters combined with an astigmatism deviation resulting from 0.27 diopters (Lens 5) from nominal performances causes a less than 25% reduction in acuity that can be slightly perceived by some users.
[000115] Table III below summarizes the maximum values of mean power deviation ΔP and resulting astigmatism ΔA of the lenses considered and provides the resulting reduction in acuity according to a relationship given in the publication by Fauquier et al. above mentioned.

[000116] The Applicant considers a reduction in AC accuracy (%) of 30% to be discriminatory.
[000117] The normalized limit value of 5.0.10'5 mnr2.dioptria'1 for the fourth derivative Ü4 and / or the limit values of 7.5.10'1mm-1 / 1.45 mm1 for the sphere gradients / cylinder on at least a central portion of the front regressive surface determines that the lens can be easily manufactured meeting the nominal optical performances.
[000118] The semifinished lens model of the invention can be manufactured by digital planing or molding. The first surface of the semifinished lens model is determined by adjusting a regression of the mean sphere value between the wide view zone 26 and the approximate vision zone 28 and a derivative quarter relative to the altitude value Ü4 less than 5, 0.10'5 mm ^ diopter1 at any point in a central portion. Other criteria as defined above, notably, limit values for sphere gradients and cylinder gradients, can also be used when determining the first surface of the semi-finished lens model.
[000119] The data for the first determined surface will be used to control the machining of a mold or to control a digital planing machine to produce the first surface of the semi-finished lens model.
[000120] A progressive lens can be manufactured using a semi-finished lens model, according to the invention.
[000121] FIG. 83 is a flow chart of an example of the steps that can be taken to manufacture a progressive ophthalmic lens according to the invention.
[000122] Data relating to a user is provided (step 74). This can be done in a first location, that is, an eyeglass seller (optician). Data is transmitted (step 75) from the first location to a second location in which a semi-finished lens model is selected (step 77) and in which an optical optimization of the lens based on data relating to the user and data relating to the first regressive surface of the semi-finished lens model is performed (step 78). This can be done in a lens designer’s lab. The semi-finished lens model can be selected based on user data, for example, the prescribed addition. The results of the optical optimization are transmitted (step 80) and a second lens surface is determined (step 81) according to the result of the optical optimization. This can be done in the same laboratory, or in a different laboratory. The data for the second surface is transmitted (step 82) to a lens manufacturer. Using the selected lens model, the lens manufacturer flattens the model's unfinished surface according to the second determined surface (step 83). The unfinished surface of the model can be made by digital planing or molding.
[000123] The progressive lens of the invention can also be manufactured without using a semi-finished lens model.
[000124] Data relating to a user is provided (step 74). The data is transmitted (step 75) from the first location to a second location where a first surface is determined (step 76). This can be done in a lens designer’s lab. The first surface is determined using the criteria previously defined and in a notable way, a regression of the mean sphere value between at least a portion of the wide view zone 26 and at least a portion of the close view zone 28, a gradient sphere value less than 7.50.101 mm1 at any point in a central portion of the lens, a cylinder gradient value less than 1.45 mm1 at any point in the central portion of the lens and a fourth derivative in relation to the altitude value (D4) less than 5,105 mm 2.dioptric1 at any point in the central portion of the lens.
[000125] The data relating to the first surface are transmitted and an optical optimization of the lens based on the data relating to the user and the data relating to the first surface is carried out (step 78). This can be done in the same laboratory as determining the first surface, or in a different laboratory. The results of the optical optimization are transmitted (step 80) and a second lens surface is determined (step 81) according to the result of the optical optimization. This can still be done in the same lab, or in a different lab. The data for the first and second surfaces are transmitted (step 82) to a lens manufacturer and the lens is produced by digital double-sided flattening (step 84) or by molding.
[000126] These methods can be implemented on a computer. Computer program products may be provided comprising one or more stored instruction strings that are accessible to a processor and which, when executed by the processor, cause the processor to perform the method steps are also proposed.
[000127] Such computer programs may be stored on a computer-readable storage medium, such as, but without limitation, any type of disk that includes floppy disks, optical disks, CD-ROMs, magnetic optical disks, read-only memories (ROMs), random access memories (RAMs), electrically programmable read-only memories (EPROMs), electrically erasable and programmable read-only memories (EEPROMs), magnetic or optical cards, or any other type of media suitable for storing electronic instructions and capable of being coupled to a computer system bus. A computer-readable medium that performs one or more sequences of instructions from the computer program product is thus proposed. This allows you to perform the method at any location.
[000128] A set of apparatus for manufacturing a progressive ophthalmic lens, in which the apparatus is adapted to carry out the method for manufacturing is also proposed.

权利要求:
Claims (5)
[0001]
1. Progressive ophthalmic lens comprising a front surface and a rear surface, each surface having, at each point, an altitude (z), an average sphere value (average SPH) and a cylinder value (CYL), at least one surface comprising two micro-markings and a central point located in the center of a segment connecting the two micro-markings, where the central portion of the lens is a 40 mm diameter circle centered on the central point, the lens characterized by the fact that the front surface of the lens comprises : - a remote viewing zone (26) having a remote viewing point (PV); - an approximate vision zone (28) having an approximate vision reference point (NV); - a main meridian (32), where the front surface is regressive and has: - a normalized sphere gradient (GradSPH) value of less than 7.50.101 mm1 at any point in the central portion of the lens including a portion of the meridian main (32), the distant view reference point (FV) and the approximate view reference point (NV), where the normalization factor is equal to the maximum value of the surface addition; - a cylinder gradient normalized value (GradCYL) of less than 1.45 mm1 at any point in the central portion of the lens, where the normalization factor is equal to the maximum value of the addition of the surface.
[0002]
2. Semi-finished spectacle lens model having a first regressive surface and a second unfinished surface, the first regressive surface having, at each point, an altitude (z), an average sphere value (average SPH) and a cylinder value (CYL ), having markings that define a position of a central point of the model, in which the central portion of the model is a 40 mm diameter circle centered on the central point, the model characterized by the fact that the first regressive surface comprises: - a zone far-sighted (26) which has a far-sighted reference point (FV); - an approximate vision zone (28) that has an approximate vision reference point (NV); - a main meridian (32), and where the first regressive surface has: - a normalized sphere gradient (GradSPH) value of less than 7.50.101 mm1 at any point in the central portion of the model that includes a portion of the meridian main (32), the distant view reference point (FV) and the approximate view reference point (NV), where the normalization factor is equal to the maximum value of the surface addition; and - a cylinder gradient normalized value (GradCYL) of less than 1.45 mm1 at any point in the central portion, where the normalization factor is equal to the maximum value of the surface addition.
[0003]
3. Method for manufacturing a semi-finished lens model, with markings that define a position of a central point of the model, in which the central portion of the model is a 40 mm diameter circle centered on the central point, characterized by the fact that it comprises the steps to: - define a first surface and a second unfinished surface, the first surface having, at each point, an altitude (z), an average sphere value (average SPH) and a cylinder value (CYL); - define a distant vision zone (26) that has a distant vision reference point (FV), an approximate vision zone (28) that has an approximate vision reference point (NV), a main meridian (32) and a central portion of the first surface that includes a portion of the main meridian (32), the distant view reference point (FV) and the approximate view reference point (NV); - determining the first surface that has: - a regression of the mean sphere value (ASPHmedium) between at least a portion of the wide-view area (26) and at least a portion of the close-up area (28); and - a sphere gradient normalized value (GradSPH) of less than 7.50.101 mm1 at any point in the central portion, where the normalization factor is equal to the maximum value of the addition of the surface; and - a cylinder gradient normalized value (GradCYL) of less than 1.45 mm1 at any point in the central portion, where the normalization factor is equal to the maximum value of the surface addition; - flatten or shape the first surface.
[0004]
4. Method for making a progressive ophthalmic lens, characterized by the fact that it comprises the steps of: - providing data relating to a user, - selecting a semi-finished lens model as defined in claim 2; - perform an optical optimization of the lens based on the data relating to the user and the data relating to the first regressive surface of the model, - supply the selected semi-finished lens model and flatten or shape the model's unfinished surface according to the result of the optical optimization.
[0005]
5. Method for making a progressive ophthalmic lens having a first and a second surface on which at least one surface comprises two micro-markings and a central point located in the center of a segment connecting the two micro-markings, where the central portion of the lens is a 40 mm diameter circle centered on the central point, characterized by the fact that it comprises the steps of: - providing data relating to a user, - defining the far-sighted area (26) which has a far-sighted reference point (FV) , a close view area (28) that has a close view reference point (NV), a main meridian (32), - define a first lens surface that has: - a mean sphere value regression (ASPHmedium) between at least a portion of the remote viewing area (26) and at least a portion of the approximate viewing area (28); - a normalized sphere gradient (GradSPH) value of less than 7.50.101 mm1 at any point in the central portion of the lens that includes a portion of the main meridian (32), the far-sight reference point (FV) and the approximate vision reference point (NV), where the normalization factor is equal to the maximum value of the addition of the surface; - a cylinder gradient normalized value (GradCYL) of less than 1.45 mm1 at any point in the central portion of the lens, where the normalization factor is equal to the maximum value of the addition of the surface; - perform an optical optimization of the lens based on the data relating to the user and the data relating to the first lens surface; - determine a second lens surface according to the result of the optical optimization; - flatten or shape the first and second surfaces.

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CN106716231B|2020-01-07|Multifocal lens supply system for providing customized progressive spectacle ophthalmic lenses to a wearer

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US20200278565A1|2020-09-03|Set of ophthalmic lenses

同族专利:

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公开号 | 公开日

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WO2012130736A2|2012-10-04|

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AU2012234416A1|2013-09-26|

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BR112013024787A2|2016-12-27|

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JP6069296B2|2017-02-01|

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KR101902372B1|2018-09-28|

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CA2830638A1|2012-10-04|

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ZA201306748B|2015-03-25|

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WO2012130736A3|2012-11-22|

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US20140016088A1|2014-01-16|

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JP2014512023A|2014-05-19|

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US9454019B2|2016-09-27|

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CN103460117B|2015-12-09|

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IN2013CN08611A|2015-08-21|

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RU2013148568A|2015-05-10|

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AU2012234416B2|2015-06-11|

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CA2830638C|2018-07-24|

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EP2506063A1|2012-10-03|

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EP2691806A2|2014-02-05|

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CN103460117A|2013-12-18|

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KR20140015399A|2014-02-06|

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ES2657857T3|2018-03-07|

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EP2691806B1|2017-11-15|

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RU2589295C2|2016-07-10|

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法律状态:
2018-08-14| B25A| Requested transfer of rights approved|Owner name: ESSILOR INTERNATIONAL (FR) |

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2018-12-18| B06F| Objections, documents and/or translations needed after an examination request according [chapter 6.6 patent gazette]|

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2020-01-14| B06U| Preliminary requirement: requests with searches performed by other patent offices: procedure suspended [chapter 6.21 patent gazette]|

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2020-05-19| B09A| Decision: intention to grant [chapter 9.1 patent gazette]|

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2020-10-13| B16A| Patent or certificate of addition of invention granted [chapter 16.1 patent gazette]|Free format text: PRAZO DE VALIDADE: 20 (VINTE) ANOS CONTADOS A PARTIR DE 22/03/2012, OBSERVADAS AS CONDICOES LEGAIS. |

优先权:

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申请号 | 申请日 | 专利标题

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EP11305381.3|2011-03-31|

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EP11305381A|EP2506063A1|2011-03-31|2011-03-31|Progressive ophthalmic lens|

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PCT/EP2012/055146|WO2012130736A2|2011-03-31|2012-03-22|Progressive ophthalmic lens|

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