ES2577013A1 - Progressive lens with compensation prism, pair of progressive lenses with binocular prismatic compensation comprising at least one lens of this type, and glasses that understand the lens pair (Machine-translation by Google Translate, not legally binding) - Google Patents

Abstract

Progressive lens to compensate the prismatic difference between right eye (4) and left eye (5) of a patient produced by anisometropia, comprising a convex external face (2) and a concave inner face (3), a surface (8a) with an atoric progressive, an upper zone with a far vision zone (6), a lower zone with a near vision zone (7), a progressive transition vision zone (8) that starts at the bottom of the zone of far vision (6) and ends in the upper part of the near vision zone (7), and a compensating prism (9) integrated in the lens (1), where the surface (8a) with the atomic progressive is formed in the inner concave face (3), and the compensation prism (9), both upper and lower base, is part of the surface (8a) with the atoric progression formed in the lower area of the inner concave face (3), and whose manufacturing process can be carried out in a single step by size of the surface icie concave (8a). (Machine-translation by Google Translate, not legally binding)

Description

PROGRESSIVE LENS WITH COMPENSATION PRISM, LENS COUPLE PROGRESSIVE WITH BINOCULAR PRISM COMPENSATION THAT 5 UNDERSTAND AT LEAST ONE LENS OF THIS TYPE, AND GLASSES THAT UNDERSTAND THE LENS COUPLE

Technical Field of the Invention

The present invention falls within the field of corrective lenses for visual defects, and particularly in the technical field of progressive lenses with prismatic compensation ("slab-off") used in the correction of anisometropies.

State of the art prior to the invention

15 For its convenience to the user, progressive lenses have become increasingly important for the correction of vision defects, particularly presbyopia, as they allow the user to view at all distances from their far vision point to their Progressively "soft" near vision point without the jumps

20 abrupt vision that usually occurs in bifocal lenses.

The progressive lenses comprise several zones namely an upper zone for distant or maximum distance vision, a lower zone for near vision, and an intermediate zone between those zones for intermediate vision. The intermediate zone enables

25 progressive transition between far vision and near user vision.

Anisometropia occurs when the eyes of a user have different ametropias in terms of degree or type, for example one eye with myopia and the other with farsightedness, one eye with strong myopia and the other with only mild myopia, one eye with

30 strong farsightedness and the other with only mild farsightedness, one eye with myopia and the other with astigmatism, etc.

When a user with anisometropia who wears glasses with progressive lenses moves their eyes, they look through peripheral areas of the lenses, other than the optical center, which

35 results in prismatic effects that condition that, when the user looks through the areas

lower of the lenses, the image that it perceives is located above or below the real object to which the image corresponds, producing a vertical mismatch in the vision. The term anisometropia is used when there is a difference in the refraction of the far vision point of more than 0.25 diopters between the right eye and the user's left eye. It is usually considered that, in the case of users with anisometropia who wear glasses with progressive lenses, vision problems do not occur until said refractive difference does not exceed 1.5 diopters, since there is a minimum degree of independence in the vertical eye movement, and also the user's brain is able to fuse the image from each eye thus maintaining binocular vision and

10 compensate for the aforementioned vertical mismatch. From this value, the vertical mismatch is usually greater than the user's brain can comfortably compensate, so that double vision problems can occur.

Various progressive lenses have been devised to optimize lenses intended to correct anisometropia.

Thus, patent application US2010296052A1 describes an optimization process aimed at correcting objective vertical prismatic differences of a lens of a pair of lenses in front of the other lens with which it forms a pair, in which the entire 20 of the concave surface is modified interior based on the evaluation of a group of points of the lens, based on which the surface of the lens is modified at a specific level to approximate the objective of prisms, so that each point of the lens is modified to prism level differently and independently. In this way, it is intended to achieve objective prismatic differences that diminish the original prismatic differences without ever reaching a zero prismatic difference. This results in a local variation of the orientation of the lens surface to vary the prism at that point, so that the power of the lens varies at that point and at points near it, since, as is known, the Power and prismatic effect are closely linked to each other. The result of this is that, since the

30 optimization at many points, the entire power map undergoes variations, and when maps of prismatic differences are minimized, the power maps get worse.

Patent application US2011194070A1 describes a lens with a progressive on its outer face and with a continuous, toric or spherical concave internal face, oriented 35 by applying a single prism, and in which the vertical prism is only controlled

at a point. The concave internal surface is oriented with a particular prism, broken down into a horizontal component that is desired to be located at the lens set point and in a vertical prism that is desired to be located at the reference point of the prism. The fact that the progressive is convex rather than concave implies limitations of

5 calculation and, as a consequence, losses in the optical quality of that lens. In addition, the vertical prism is only controlled at a single point of the lens, which implies that the problems of prismatic differences are only resolved at a single point of the lens.

For users suffering from anisometropia there are also progressive lenses

10 conventional ones that integrate a compensation prism ("slab-off prism") to compensate for the vertical prismatic difference at the near vision reference point. The "slab-off" technique for the manufacture of progressive lenses comprises a method of carving on an already finished lens by means of which a compensation prism is generated to equalize the right and left eye prisms at the reference point for

15 near vision. Such lenses are, for example, those marketed by the German firm ZEISS and are described at http://www.zeiss.com/vision-care/en_de/eye-careprofessionals/optical-knowledge/for-the-expert/special- production / slab-off-technique.html. The progressive lens of Zeiss with compensation prism to compensate for the prismatic difference between right eye and left eye produced by anisometropies, consists of a

20 upper zone comprising the far vision zone, a lower zone comprising the near vision zone and between both zones, an intermediate zone intended for the intermediate vision where the progressive transition of power from far to near occurs. This conventional progressive lens comprises a convex progressive outer face, an atomic concave inner face and the compensation prism that is subsequently applied to the

25 manufacturing of the progressive lens on the concave face, that is, this prism is applied on the opposite face to which the progressive surface is.

The manufacturing process in this type of conventional progressive lenses means that it must be done in several steps, which makes the process more expensive than that of a lens without compensation prism. In addition, it only allows an upper base compensation prism to be placed in the near vision area, so that such a prism can only be placed on the lens of the pair of lenses that have the most negative or, if applicable, less positive graduation. This implies that in that conventional lens the compensation prism cannot be applied to the eye that the user decides or needs, for example to the non-dominant eye, and that in such conventional lenses the prism cannot be applied

of compensation to both eyes to distribute the prism, which makes these conventional progressive lenses not very flexible in terms of the possibility of adapting their design to the particularities of each patient with anisometropia.

5 Description of the invention

The present invention aims at overcoming the disadvantages of conventional progressive lenses provided with compensation prisms to compensate for the prismatic difference between the right eye and the left eye of a patient produced by 10 anisometropies, by means of a progressive lens with an intrinsic original prism and a compensation prism. integrated intended to be paired with another different graduation lens, and comprising a spherical or aspherical convex outer face and a concave inner face, a surface with an atoric progressive, an upper area with a far vision zone with a reference point of distant vision, a lower zone

15 with a near vision zone with a near vision reference point and a compensation prism, as well as an intermediate progressive transition vision zone that begins at the bottom of the far vision zone and ends at the top of the near vision zone, in which

20 the far vision zone has a constant first prism for all points of the far vision zone, added to the original lens prism;

the compensation prism is a second constant prism for all points in the near vision zone added to the original lens prism;

the surface with the atoric progressive is formed in the concave inner face;

the compensation prism is part of the surface with the atoric progressive formed in the lower area of the concave inner face,

the far vision reference point has zero horizontal prism; Y

The near vision reference point and the far vision reference point have zero vertical prismatic differences.

Because, according to the present invention, instead of having local prisms, only two constant prisms are arranged, namely the prism in the far vision zone and the compensation prism in the near vision zone, these two prisms they do not cause changes in the lens powers, since since the orientation of the surface to vary the prism is not changed locally, changes in the lens power are not caused, but only the prismatic constant applicable to the far vision zone and the prismatic constant applicable to the near vision zone. The presence of the compensation prism allows the vertical prism to be equalized at two reference points of the lens, which allows a very effective correction of the anisometric view

10 of the user.

The progressive lens according to the invention can be made of a plastic material known per se in the technology of manufacturing glasses lenses, such as a plastic polymer or polycarbonate, although it can also be made of glass.

15 The compensation prism may be, depending on the ametropia of the user to be corrected, an upper base prism or a lower base prism.

Another object of the invention is a pair of progressive corrective lenses of

20 different graduations, where at least one of the corrective lenses is a progressive lens with compensation prism with the characteristics recommended in the present description.

In one embodiment of the invention, the pair of lenses comprises a first lens.

25 progressive with a compensation prism and a second progressive lens without compensation prism.

In another embodiment, the lenses comprise two compensation prisms. In this case, the glasses can comprise a first progressive lens with a prism of

30 upper base compensation and the second progressive lens with a lower base compensation prism.

Another object of the invention is constituted by glasses for users with anisometropia, comprising a frame on which two corrective lenses are mounted

35 progressive graduations of different graduations, where the two lenses form a pair of lenses

as any of the previously described.

The process of manufacturing the progressive lens with compensation prism according to the present invention can be carried out by means of a process comprising carving,

5 starting from a lens body already provided with a spherical convex surface or aspherical, in a single step the entire concave surface for the lens that includes the constant prism in the far vision zone, the compensation prism in the zone of close vision, and the atoric progressive. This can be done with a shaper machine programmable, such as the FREEFORM machine.

Brief description of the figures

Embodiments of the invention will be described below based on schematic drawings, in which

Figure 1 is a front elevational view of glasses with a pair of progressive lenses, of which the left lens is a lens according to a first embodiment of the invention;

Figure 2A is a side elevational view of the conventional progressive lens for the left eye corresponding to the lens that appears on the right in Figure 1;

Figure 2B is a side elevation view of a conventional progressive lens for the right eye;

Figure 2C is a side elevational view of the progressive lens for the right eye corresponding to the lens that appears on the left in Figure 1;

Figure 3 is a front elevation view of glasses with a pair of lenses

30 for glasses in which both lenses correspond to further embodiments of the invention;

Figure 4A is a side elevational view of the progressive lens for the right eye corresponding to the lens that appears on the left in Figure 3;

Figure 4B is a side elevational view of the progressive lens for the left eye corresponding to the lens that appears on the right in Figure 3;

Figure 5 is an example of a prismatic power map that perceives the eye of a 5 conventional neutral progressive lens;

Figure 6 is an example of a prismatic power map that perceives the eye of a progressive lens with compensation prism in accordance with an embodiment of the invention;

10 Figure 7 is an astigmatism map that perceives the eye with the lens of Figure 15;

Figure 8 is an astigmatism map that perceives the eye with the lens of Figure 26;

Figure 9 is a table with the topographic data with the sagitites of the concave surface 15 of the lens corresponding to the prismatic power map of Figure 6 and the astigmatism map of Figure 8.

These figures show reference signs that identify the following:

20 1 Lens 2 Convex external face 3 Concave internal face 4 Left eye 4a Left eye cornea

25 4b Left eye retina 5 Right eye 5a Right eye cornea 5b Right eye retina 6 Far vision zone

30 6a Far vision reference point 7 Near vision zone 7a Near vision reference point 8 Transition vision zone 8th surface with atoric progressive

35 9 Compensation prism (Slab-Off)

10 Marginal Zone 11 Mount  11th Pin

5 A First object B Second object C Common object

Embodiments of the invention

10 Figure 1 shows a first embodiment of glasses with a frame -11- with pins -11a- in which two progressive lenses -1- of which one is mounted, namely the one shown on the left in Figure 1 , is a lens according to its progressive concave surface has integrated compensation prism -9- for the right eye

15 of the user, while the one on the right is a conventional progressive lens for the user's left eye.

As can be seen, both lenses -1- comprise an upper zone with a far vision zone -6-, a lower zone with a near vision zone -7- as well as a

20 progressive transition zone -8- that begins at the bottom of the far vision zone -6- and ends at the top of the near vision zone -7-. The transition zone -8- has a corridor shape and is laterally delimited between marginal areas -10- in which, as usual in progressive lenses, certain optical aberrations occur that reduce the suitability of these marginal areas for

25 foveal vision but are sufficient for peripheral vision.

As can be seen in Figures 1, 2A and 2C, each lens -1- comprises a convex outer face -2- and a concave inner face -3-. The concave inner face -3- comprises a surface -8a- with an atomic progressive corresponding to the vision zone of

30 transition -8-.

The lens for the left eye -4- is a progressive lens -1- without compensation prism, while the lens -1- progressive for the right eye (5) further comprises a compensation prism -9- which is part of the surface -8a- with the atomic progressive in the

35 lower area of the concave inner face -3-, and whose function will be explained below

with reference to figures 2A - 2C, for a user with anisometropia who wears progressive glasses with lenses -1- of different graduations for his left eye -4- with his cornea -4a- and retina -4b- and for his right eye - 5- with his cornea -5a- and retina -5b-.

5 In Figure 2A you can see schematically the left eye -4- of a user who focus an object -A- placed at a short distance, through the near vision area in the lower part of the first conventional progressive lens -1- shown in figure 1. This first lens -1- has a certain graduation, for example +1.5 diopters, whose Prismatic effect makes the left eye position and direction of view -4- this

10 see the object -A-.

In figure 2B the right eye-5- of the user can be seen schematically looking through a conventional progressive right -1-lens with the right eye -5- in the same position and direction of look as the left eye -4 - shown in figure 2A. 15 Since the right -1-lens has a very different graduation, for example of +3.5 diopters, its prismatic effect means that, although the right eye -5- is in the position that the left eye -4-, sees an object -B- which is in a different real position than the object -A- focused by the left eye -4-. In view of the difference of 2 diopters between the graduation of the -1- lenses, the user's brain is not capable of

20 to unify the images, and double vision is produced since the user sees the object -A- with his left eye -4- and the object -B- with his right eye -5-.

Figure 2C shows the effect of a progressive lens -1- with compensation prism -9- according to the invention, for the right eye -5- of the user looking therein

25 direction than your left eye -4- (figure 2A). It can be seen that the compensation prism causes the right eye -5- to also receive the image of the object -A-, so that a double vision problem does not occur between the left eye -4- (figure 2A) and the eye right -5-.

Figure 3 illustrates a second embodiment of glasses with a frame -11- with pins -11a- in which two progressive lenses -1- having two compensation prisms-9- according to the invention are mounted, for a user with anisometropia wearing progressive glasses with lenses -1- of different graduations for his left eye -4- and for his right eye -5-, for example -1.5 diopters for the eye

35 left -4- and +3.5 diopters for the right eye -5-.

As in the case of the first embodiment illustrated in Figure 1, in the case of the second embodiment illustrated in Figure 3 both lenses -1- comprise an upper zone with a far vision zone -6-, a lower zone with a vision zone

5 -7-as well as a progressive transition zone -8- that begins at the bottom of the far vision zone -6- and ends at the top of the near vision zone -7-. The transition zone -8- has a corridor shape and is laterally delimited between marginal areas -10-.

10 As can be seen in Figures 3, 4A and 4B, each lens -1- comprises a convex outer face -2- and a concave inner face -3-. The concave inner face -3- comprises a surface -8a- with an atomic progressive corresponding to the transition vision zone -8-. The lenses -1- also comprise separate compensation prisms -9- that are part of the respective surfaces -8a- with their atoric progressives in each

15 one of the lower zones of the concave inner faces -3- of the lenses -1-.

In this case, the compensation prisms -9- are designed in such a way that, when looking in the same direction, both eyes see the common object -C-. In this way the two compensation prisms -9- share the prismatic effect with each other, so that both lenses -1- have a more evenly visible and, therefore, more aesthetic appearance. This is advantageous in the case of the large difference (= 5 diopters in this exemplary embodiment) between the ametropias of the two eyes which, if only a progressive lens with compensation prism according to the invention is used in combination with a lens progressive without such a prism of compensation, would imply that the prism of

The compensation in the lens according to the invention would look very different from that of the conventional lens, which would diminish the aesthetic characteristics of the user's glasses.

Figure 5 is a map of prismatic power that perceives the eye of a progressive lens

30 conventional neutral with addition of 2, in position of use. The prismatic effects of a progressive lens can be seen in which the near vision reference point -7a- is below (actually about 18 mm) from the far vision reference point -6a-. As a consequence of the progressive geometry, the near control point will have a prismatic effect that is impossible to control. In this example that effect

35 is about 2.25 prismatic diopters. eleven

Figure 6 is a map of prismatic power that perceives the eye of a lens, in position of use, progressive neutral with the addition of 2 with compensation prism and zero prism both at the far vision reference point -6a- and in the Point of

5 near vision reference according to an embodiment of the invention. It can be seen how the prismatic effects of the lens with the progressive concave surface and with the compensation prism allow to control the prismatic effects at two reference points.

10 Figure 7 is an astigmatism map that perceives the eye with the lens of the figure. 5, in position of use. It can be seen that in the intermediate vision it has a correct area of smooth and continuous vision.

Figure 8 is an astigmatism map that perceives the eye with the lens of Figure 6, in

15 position of use. It can be seen that in a part of the transition zone astigmatisms are very high so that intermediate distance vision is optically impaired with this lens. However, this decrease will always be more beneficial for an anisometric user than the double vision that would occur without the lens with compensation prism according to the invention. In addition, when used

20 the lens corresponding to figure 6 in glasses such as those illustrated in figure 1, in which the other lens corresponds to figure 5, a monocular intermediate vision will be produced.

In cases of users with very pronounced anisometropies that, therefore, require correction of very high prismatic differences between both eyes, they can be

25 use lenses with compensation prism for both eyes, which will lead to the loss of intermediate distance vision in the aforementioned part of the transition zone. However, also in this case the shrinkage will be more beneficial for the anisometric user than the double vision that would occur without lenses with compensation prism according to the invention.

Figure 9 shows a table with the topographic data with the sagitites of the concave surface of the lens corresponding to the prismatic power map of Figure 6 and the astigmatism map of Figure 8. In particular, it shows the value of the sagite in Cartesian coordinates, so that for each value (X, Y) a Z value is defined

35 corresponding to the arrow or sagita. 12

The points (X, Y) are defined in a grid of points equidistant every 3 mm. The horizontal direction corresponds to the X coordinates, and the vertical one to the Y coordinates.

The X, Y and Z coordinates are expressed in millimeters. The values shown correspond to the progressive concave internal surface of the lens whose maps appear in Figures 6 and 8 in which you can see the locations where the reference points are located from far and near the lens.

Claims (8)

1. Progressive lens with integrated compensation prism (9) to compensate for the prismatic difference between right eye (4) and left eye (5) of a patient with 5 anisometropia, the progressive lens (1) presenting an intrinsic original prism and the progressive lens (1) being designed to pair with another lens (1) of different graduation, and comprising a spherical or aspherical convex (2) external face and an internal concave face (3), a surface (8a) with an atoric progressive, an upper zone with a far vision zone (6) with a vision reference point 10 far (6a), a lower zone with a near vision zone (7) with a near vision reference point (7a) and a compensation prism (9), and an intermediate zone (8) of progressive transition vision which begins at the bottom of the far vision zone (6) and ends at the top of the near vision zone (7), characterized in that 15 the far vision zone (6) has a constant first prism for all points of the far vision zone (6) added to the original lens prism; the compensation prism (9) is a second constant prism for all points of the near vision zone (7) added to the original lens prism; the surface (8a) with the atoric progressive is formed in the concave inner face (3); 20 the compensation prism (9) is part of the surface (8a) with the atoric progressive formed in the lower area of the concave inner face (3); the far vision reference point (6) has zero horizontal prism; and the near vision reference point (7) and the far vision reference point (6) have zero vertical prismatic differences.

2.

 Progressive lens according to claim 1, characterized in that the lens (1) is made of plastic material.

3.

 Progressive lens according to claim 1 or 2, characterized in that it has been obtained

30 by means of a process comprising carving, starting from a lens body already provided with a spherical or aspherical convex surface, in a single step the entire concave surface for the lens already finished in a single step. 4. Progressive lens according to claim 1, 2, or 3, characterized in that the prism of 35 compensation (9) is a top-base prism. 14 5. Progressive lens according to claim 1, 2, or 3, characterized in that the compensation prism (9) is a lower base prism. 5 6. Pair of progressive corrective lenses (1) of different graduations, characterized in that it comprises a first lens (1) and a second lens (1), at least one of the corrective lenses (1) being a progressive lens (1) with compensation prism (9), as defined in any one of claims 1 to 5, and because the progressive lenses (1) comprise respective prisms matched at their reference points (6a, 10 7a), so that the far vision prism of the first lens (1) has a far vision reference point (6a) equal to the far vision reference point (6a) of the far vision prism of the second lens lens, and the near vision reference point (7a) of the prism of the first lens (1) is the same as the near vision reference point (7a) of the near vision prism of the second lens (1). A pair of lenses, according to claim 6, characterized in that it comprises a first progressive lens (1) with a compensation prism (9) and a second progressive lens (1) without a compensation prism. A pair of lenses according to claim 6, characterized in that the lenses (1) comprise two compensation prisms (9). 9. Pair of lenses according to claim 8, characterized in that the first lens (1) progressive comprises a compensation prism (9) of upper base and the second progressive lens (1) comprises a compensation prism (9) of lower base. 10. Glasses for users with anisometropia, comprise a frame (11) in which two progressive corrective lenses (1) of different graduations are mounted, characterized in that the two lenses (1) form a pair of lenses such as the one 30 defined in any one of claims 6 to 9.