Multifocal lens

Abstract

A multifocal lens (1) having at least three main powers (DF, DM, DN) has a plurality of concentric annular main regions (Zi) adjacent to one another, each of which is divided into inner and outer annular sub-regions (2, 3) having different powers (D1, D2), where the lens (1) has no geometric step between all sub-regions (2, 3), where the powers (D1) of all inner sub-regions (2) are equal to one another, and where the refractive powers (D1, D2) of all outer sub-regions (2, 3) are equal to one another. The refractive powers (D2) of all the inner and outer sub-regions (2, 3) are equal to each other, and wherein all the inner and outer sub-regions (2, 3) share their respective main region (Zi) at an equal area ratio in the range of 30: 70 to 70: 30.

Description

Technical Field

[0001] The present invention relates to a multifocal lens with at least three main refractive powers, which has a plurality of concentric annular main areas adjacent to each other, each of the plurality of main areas is divided into inner and outer annular sub-areas with different refractive powers, and the lens has no geometric steps between all the sub-areas. Background Art

[0002] Such lenses are typically used as ophthalmic lenses, for example as contact lenses, intraocular lenses (IOLs), intracorneal lenses or spectacle lenses.

[0003] Trifocal lenses are already known. In most cases, these are diffractive lenses of annular zones of equal area (so-called "Fresnel zones"), with geometric steps being provided between the zones. In such trifocal lenses, the heights of the individual steps are usually different in alternation. Figure 1 The through focus response (TFR) of such a lens with 28 zones is shown, wherein the steps between the respective equal-area annular zones are alternately high, so that the optical path length difference is 0.65λ and 1.35λ, where λ represents the wavelength of light. However, such steps are complicated to produce, which leads to high manufacturing costs.

[0004] In addition, trifocal refractive-diffractive lenses are known, in which the steps are replaced by so-called small-area "phase sub-regions" whose refractive power is significantly different from the refractive power of another so-called "phase main region", thereby achieving corresponding optical path length differences between the individual phase main regions (e.g., EP1194797B1, EP2564265B1). Such trifocal lenses exhibit a complex refractive power distribution from the inside to the outside, and the process of changing the area ratio between the phase sub-regions and the phase main region is therefore usually complex to manufacture. Summary of the invention

[0005] The object of the present invention is to create a multifocal lens with at least three main refractive powers which is easy and economical to manufacture.

[0006] This object is achieved by a multifocal lens of the type described at the outset, which is characterized according to the invention by the fact that the refractive powers of all inner sub-areas are in each case equal to one another and the refractive powers of all outer sub-areas are in each case equal to one another and that all inner and outer sub-areas share their respective main areas in an equal area ratio, which is in the range from 30:70 to 70:30.

[0007] The basis of the invention is the explicit consideration of interference phenomena between light coming from different sub-areas or main areas. By combining alternating sub-area powers and a special area ratio between inner and outer sub-areas, the invention creates a multifocal lens which can have three or more main powers, at least one of which is diffractive. Due to the simple surface profile route with alternating powers of sub-areas, the multifocal lens of the invention is particularly easy and economical to manufacture, with equal area ratios of the pairs of sub-areas forming the main areas and without geometric steps. Furthermore, the lens according to the invention enables a variety of divisions of the light intensity into its main powers, for example, an even division to obtain good vision at long, intermediate and near distances.

[0008] In a preferred embodiment, all main regions have the same area. As a result, the main regions have the area ratio of a Fresnel zone lens, which simplifies the generation of at least one diffractive main refractive power by interference between the sub- and main regions. In an alternative embodiment, the areas of the plurality of main regions increase or decrease monotonically from the inside to the outside, whereby the respective main refractive power can be given according to the aperture size, for example a pinhole or the pupil of an eye.

[0009] If the area of ​​each main region is less than 2.2πmm 2 , preferably less than πmm 2 , particularly preferably less than 2π / 3mm 2 , then for visible light, the diffraction main refractive power of the lens can be generated particularly easily.

[0010] In a particularly advantageous embodiment, the above-mentioned area ratio is preferably in the range of 40:60 to 60:40, particularly preferably 50:50, in terms of production technology.

[0011] The lens may have any number of primary regions, for example more than 50 or more than 100. If the lens has 5 to 50 primary regions, preferably 10 to 20 primary regions, its surface profile may remain simple, while at the same time its at least one primary diffraction power may be formed by diffraction of light at sub-regions with sharp focus and at the primary regions.

[0012] In another preferred embodiment, the lens has a far power, an intermediate power and a near power as its main powers, wherein the difference between the near power and the far power is in the range from 1 to 6 diopters, preferably in the range from 2.0 to 4.5 diopters. In this way, when the lens is used, in particular as an IOL, both near and far objects can be focused well. Furthermore, intermediate objects can also be focused well if the difference between the intermediate power and the far power is in the range from 1.4 to 2 diopters, preferably in the range from 1.6 to 1.8 diopters.

[0013] In principle, the lens may have one or two main refractive powers that coincide with the refractive powers of the inner and / or outer sub-regions. In an advantageous embodiment, all sub-regions in combination form a diffraction grating which generates the at least three main refractive powers of the lens by diffraction. As a result, none of the individual main refractive powers of the lens coincides with any of the refractive powers of its individual sub-regions, and the main refractive powers may be determined purely by taking into account interference phenomena between light from different sub-regions or main regions.

[0014] In an advantageous combination of the latter two embodiments, the distance optical power may be generated by a negative first diffraction order (also referred to as a "diffraction order") of the lens. While the use of such a diffraction order for distance optical power has traditionally been discouraged due to its longitudinal chromatic aberration, it is now recognized for the first time that this same longitudinal chromatic aberration may be advantageously used to simulate or compensate for the refractive chromatic aberration present in the lens of a human or animal eye. In particular, the lens may have a diffractive longitudinal chromatic aberration for the negative first diffraction order for light between 450 nm and 650 nm, which is in the range from 0.1 to 1.2 diopters, preferably in the range from 0.3 to 0.7 diopters, and particularly preferably in the range from 0.35 to 0.55 diopters.

[0015] In an advantageous embodiment of the lens, in particular as an IOL, the refractive power of the inner sub-region or the refractive power of the outer sub-region is in the range from -2.5 to 2.5 diopters around the smallest of the at least three main refractive powers, preferably in the range from -2.0 to 2.0 diopters around the smallest of the at least three main refractive powers, whereby the main refractive power of the lens may be in the range of the refractive power of the human eye lens. For the same purpose, in another advantageous embodiment that may be optionally combined therewith, the refractive power of the inner sub-region or the refractive power of the outer sub-region may be in the range from -2.5 to 2.5 diopters around the largest of the at least three main refractive powers, preferably in the range from -2.0 to 2.0 diopters around the largest of the at least three main refractive powers.

[0016] Each sub-region may be uniform. Alternatively, at least one inner or outer sub-region may be divided into a plurality of local regions, the average refractive power of the plurality of local regions corresponding to the refractive power of the corresponding sub-region. In this way, one or more sub-regions may, for example, have a discrete or continuous through-focus response, which enables various manufacturing options for the lens and a variety of available diffraction patterns. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The present invention will be explained in more detail below with reference to the exemplary embodiments shown in the accompanying drawings. In the drawings: Figure 1In the intensity-power diagram the through focus response (TFR) obtained with a trifocal lens according to the prior art at a light wavelength of 550 nm is shown; Figure 2 A first embodiment of a trifocal lens according to the invention is shown in a half-section perpendicular to its rotational symmetry axis A; Figure 3 A half section perpendicular to the axis A shows Figure 2 Central detail of the lens III, with x-axis expansion for better recognition; Figure 4 In the intensity-power diagram, it is shown that Figure 2 and Figure 3 The defocus response of the lens at a light wavelength of 550nm; Figure 5 The comparative line graph shows the utilization Figure 2 and 3 The modulation transfer function (MTF) obtained by the lens; Figure 6 In the intensity-power diagram, it is shown that Figure 2 and Figure 3 The through-focus response obtained for an exemplary variation of the lens at a light wavelength of 550 nm; Figure 7 In the strength-power diagram, the through-focus response obtained with the trifocal lens according to the second embodiment of the present invention at a light wavelength of 550 nm is shown; Figure 8 In the strength-power diagram, the through-focus response obtained at a light wavelength of 550 nm using the trifocal lens according to the third embodiment of the present invention is shown; Fig. 9 The intensity-power diagram shows that for polychromatic light with wavelengths from 450 nm to 650 nm, using Figure 2 and 3 The defocus response obtained by the lens; Fig.10a and 10b In each case the intensity-power diagrams show the optical power of the trifocal lens according to the invention at a light wavelength of 550 nm ( Fig.10a ) or using polychromatic light with a wavelength of 450nm to 650nm ( Fig.10b ) obtained, differing in the area ratio of their consecutive main regions; Fig.11 The dependence of the refractive power of the human eye on the wavelength of light is shown in a refractive power-wavelength diagram; and Fig.12 In the intensity-power diagram, it is shown that Figure 2 and Figure 3 Diffractive longitudinal chromatic aberration of a lens obtained using two through-focus responses at light wavelengths of 450nm and 650nm. DETAILED DESCRIPTION

[0018] About showing the prior art Figure 1 , with reference to the introductory remarks.

[0019] Figure 2 and 3 A multifocal lens 1 according to the invention is shown, which has at least three main refractive powers, in particular a distance refractive power D for vision of distant, intermediate and near objects, respectively. F , intermediate refractive power D M and near refractive power D N ( Figure 4 ). The lens 1 can be used, for example, as an ophthalmic lens, for example as a contact lens, an intraocular lens (IOL), an intracorneal lens or a spectacle lens, or as an optical element, for example as a reflector, a converging or diverging lens. The lens 1 can be made of any material suitable for this purpose, for example glass, acrylic, silicone, hydrogel, polymethylmethacrylate (PMMA), etc.

[0020] The lens 1 has several (two, three or more) main regions Z concentrically arranged around its axis of rotational symmetry A. i (i=1,2,…,i), they are adjacent to each other. That is, (in Figure 3 Middle: In the radial direction R), from inside to outside, the second main zone Z2 is adjacent to the first main zone Z1 with the inner radius R1 of the first main zone Z1 (measured from the optical axis A), and the third main zone Z3 is adjacent to the second main zone Z2 with the inner radius R2 of the second main zone Z2, without any additional optical zone being inserted. Main zone Z i The number i>1 can be determined based on the total diameter of the lens 1 and the near refractive power D N With far refractive power D F and is typically in the range of from 5 to 50, especially in the range of from 10 to 20.

[0021] Each main area Z i Subdivided into inner sub-areas 2 and outer sub-areas 3 with different refractive powers from one another, represented here by the formula symbols "D1" and "D2", respectively. The refractive power D1 of all inner sub-areas 2 and the refractive power D2 of all outer sub-areas 3 are the same in each case, that is, each inner sub-area 2 has a refractive power D1, and each outer sub-area 3 has a refractive power D2.

[0022] In addition, in each main area Z iIn the embodiment, the area ratio between the inner and outer sub-regions 2, 3 is equal and is in the range of 30:70 to 70:30. If each inner sub-region 2 is i The area ratio of each outer sub-region 3 to its main region Z is represented by p1. i The area ratio of is denoted by p2, and thus the inequality 30:70≤p1:p(2)≤70:30 applies. In most embodiments, the area ratio P1:p2 is between 40:60 and 60:40, and in some embodiments it is substantially 50:50.

[0023] like Figure 3 As shown, the lens 1 has no steps between all sub-regions 2 and 3, that is, in each main region Z i There are no steps between the sub-regions 2, 3 and between their respective sub-regions 2, 3. Therefore, the lens surface 4 which results in the multifocality of the lens 1 is continuous.

[0024] The main refractive power D of lens 1 F , D M , D N At least one of them is diffractive, i.e., is produced by a diffraction effect at the lens 1. Therefore, the basis of the lens 1 disclosed here is to explicitly consider the radiation from each sub-area 2, 3 or main area Z i Therefore, each main area Z i The area can be selected to be less than 2.2πmm 2 , for example, less than πmm 2 or less than 2π / 3mm 2 In some embodiments, all sub-regions 2 and 3 are combined to form a diffraction grating, which generates all (here: three; or: four or more) main refractive powers D of the lens 1. F , D M , D N , ... Then, all the main refractive powers D of lens 1 F , D M , D N , ... are diffractive, and in most embodiments, the refractive powers D1, D2 in the sub-regions 2, 3 are equal to the resulting main refractive power D of the multifocal lens 1. F , D M , D N , ... do not overlap.

[0025] exist Figure 2 and 3 In the exemplary embodiment of the lens 1 shown, this is an intraocular lens (IOL) with a refractive index of 1.458. The main refractive power D of the lens 1 F , D M , D N20, 21.7 and 23.4 diopters, the refractive power D1 of the inner sub-area 2 is 19.8 diopters and the refractive power D2 of the outer sub-area 3 is 23.8 diopters. On the front side 5 of the lens 1, there is a lens surface 4 with all sub-areas 2, 3 that produces a multifocal. Alternatively or additionally, the back side 6 of the lens 1 can also have such a lens surface 4 with main and sub-areas 2, 3. In one embodiment, the lens 1 is a toric lens, wherein the lens surface facing away from the lens surface 4 has the shape of a toric cap.

[0026] exist Figure 2 In the scaled view of FIG. 2 , the different refractive powers D1 , D2 present in the individual sub-areas 2 , 3 are not visible. Figure 3 4 is shown in such a way that the x-axis parallel to the optical axis A is stretched by a factor of 13.3 in order to clearly show the individual main regions Z i The different curvatures in .

[0027] from Figure 2 and 3 As can be seen from the illustration in , the lens 1 disclosed here is easier to manufacture than, for example, a diffractive lens according to the prior art with steps between individual regions. In particular, the lens 1 can have a continuous lens surface 4 on the front and / or rear side 5, 6 in this way.

[0028] exist Figure 2 and 3 In the exemplary embodiment shown, the lens 1 has fourteen main zones Z of equal area with a diameter of 6.02 mm. i (i.e. Fresnel zone). The diameter d1=2r1 of the central main zone Z1 is 1.6088 mm; the inner diameter d1=2r1 of the annular second main zone Z2 adjacent to the main zone Z1 is 1.6088 mm, and the outer diameter d2=2r2 is 1.6088 mm. The outer diameter d3=2r3 of the third main area Z3 is 1.6088 The i-th main region Z i The inner diameter d i-1 =2r i-1 is 1.6088 Outer diameter d i =2r i is 1.6088 In the example considered, the area components p1 of the various inner sub-areas 2 are each equal to the corresponding main area Z i 52.5% of the area of ​​the outer sub-region 3, and the area components p2 of each outer sub-region 3 are each equal to the corresponding main region Z i 47.5% of the area.

[0029] exist Figure 4The final through focus response (TFR) of lens 1 is shown in the graph of intensity I versus refractive power D. Figure 4 It can be seen that in the three main refractive powers D F =20 diopters, D M =21.7 diopters, D N = Integrated intensity I in 23.4 diopters F ,I M ,I N , totaling 84% of the total integrated intensity, with the remaining 16% of the intensity present in secondary maxima occurring at 18.3 and 25.1 diopters, respectively.

[0030] Modulation transfer function (MTF) is often used to evaluate imaging characteristics. Figure 5 In, for Figure 2 and 3 The three main refractive powers D of lens 1, 550nm wavelength F , D M , D N The MTF in is expressed as curves 7-9 of contrast K versus line density L (number of lines per degree), i.e., for far refractive power D F Curve 7, for the intermediate refractive power D M Curve 8 and for near refractive power D N Curve 9. For the lens 1 in question, the MTFs of the respective main powers at intermediate and near distances (curves 8 and 9) are practically identical; the MTF of the far power (curve 7) is slightly higher than the MTFs of the other two main powers.

[0031] It should be noted that at the same diameter of 6.02 mm, the near refractive power D N and distance refractive power D F A conventional diffractive trifocal lens with the same power distance of 3.4 diopters between the zones would require 28 Fresnel zones with 27 steps, i.e., discontinuities between the zones, in order to obtain Figure 1 On the other hand, the lens 1 of the present disclosure does not need to have a defocus response in the main area Z i Or any step between sub-areas 2 and 3.

[0032] for Figure 2 and 3 The following parameters are selected for the exemplary lens 1 in: D1 = 19.8 diopters, D2 = 23.8 diopters, D F = 20 diopters, D M =21.7 diopters, D N = 23.4 diopters, p1 = 0.525 and p2 = 0.475. It can be seen that the final main refractive power D of lens 1 F , DM , D N Each of is not equal to the refractive power D1 and D2, and therefore may be attributed to interference phenomena.

[0033] In addition, the relationship applies to the intermediate principal power D (M) : D M = D1 · p1 + D2 · p2 (1)

[0034] Difference D N -D F does not depend on the choice of refractive powers D1 and D2, but only on the area of ​​the main area or sub-area 2, 3, and can be determined, for example, according to D for a main area 2 of the same area. N -D F =(2.2πmm) / (F·10 3 ), where F is expressed in mm 2 The area of ​​the main region in units.

[0035] Therefore, one of the refractive powers D1 or D2 can be freely selected within certain limits. For example, if D1 is freely selected, the following applies: D1 · p1 + D2 · p2 = D M = D1 · p1 + D2 · (1 – p1) (2) thus: D2 = (D M – D1 · p1) / (1 - p1) (3)

[0036] For example, if a value of 20.5 diopters is used for D1, and D M Again being 21.7 diopters, equation (3) gives a value of 23.0263 diopters for D2 for area components p1 = 0.525 and p2 = 0.475.

[0037] Instead of D1, D2 can also be specified, and then D1 will be generated by the relationship D1 = (D M – D2 · p2) / ( 1 - p2) (4)

[0038] As discussed, for example, using lens 1 through I main areas Z iTo achieve trifocals, each main area is subdivided into two subareas 2, 3, which have different refractive powers D1, D2. For the sake of completeness, it should be noted that each subarea 2, 3 can also be subdivided into additional local areas (not shown). If the refractive power of all local areas of the subarea 2 or 3 averaged over the subarea area corresponds to the refractive power D1 or D2, the defocus response is essentially the same as the case where only a single refractive power D1 or D2 is used for each subarea 2, 3. In general, each of the respective refractive powers D1, D2 of the subareas 2, 3 can be replaced by any continuous refractive power distribution within the subareas 2, 3, as long as the average value of the refractive power distribution formed over the subarea area corresponds to the required individual refractive powers D1 or D2.

[0039] Figure 6 Shows Figure 2 and 3 The through-focus response of a variant of lens 1 in , wherein each sub-region 2, 3 consists of two local regions of equal area. The two local regions of each inner sub-region 2 have 19.5 diopters and 20.1 diopters, respectively, and the two local regions of each outer sub-region 3 have 23.4 diopters and 24.2 diopters, respectively. Therefore, the average value of each sub-region 2 is 19.8 diopters, the average value of each sub-region 3 is 23.8 diopters, and the other parameters correspond to Figure 2 and 3 The parameters of lens 1. As shown in the figure, Figure 4 and 6 The through focus responses of are effectively the same. Alternatively, sub-regions 2 and 3 may each have a varying refractive power distribution, the respective averages of which are given by D1 and D2.

[0040] Figure 7 The defocus response of another embodiment of the lens 1 for 550nm monochromatic light is shown, wherein in each main area Z i The area components of sub-regions 2 and 3 at φ1 are equal, that is, p1=p2=0.5. Here, the inner sub-region 2 has a refractive power D1 of 18 diopters, and the outer sub-region 3 has a refractive power D2 of 25 diopters. As shown in the figure, the lens 1 has three main refractive powers D1 of 18.5 diopters, 21.5 diopters and 24.5 diopters. F , D M , D N , each refractive power has approximately equal intensity I F ,I M ,I N .

[0041] In the embodiments described so far, the final main refractive power D of the lens 1 is F , D M , D NIt does not correspond to the refractive powers D1 and D2 of each sub-area. Figure 8 shows the through focus response of an alternative embodiment, where the distance power D F Corresponding to the refractive power D1 of the inner sub-area 2, the near refractive power D N Corresponding to the refractive power D2 of the outer sub-area 3, two types of sub-areas 2 and 3 are arranged in each main area Z. i have the same area ratio, that is, p1 = p2 = 0.5. Figure 8 As shown, the intermediate refractive power D M With strength I M , which is higher than the two other main refractive powers D F , D N Strength I F ,I N .

[0042] The operation principle of the lens 1 for monochromatic light has been explained so far. Fig. 9 Shows Figure 2 and 3 The through-focus response of lens 1 in FIG. 1 for polychromatic light, the spectrum of which extends from 450 nm to 650 nm. The far refractive power D of 20 diopters F Corresponding to the negative first diffraction order of lens 1, the near refractive power D of 23.4 diopters N Corresponding to the positive first diffraction order, the intermediate refractive power D of 21.7 diopters M The positive and negative first diffraction orders each exhibit a diffraction chromatic aberration, and as a result, the peak intensity I in these diffraction orders of polychromatic light is F，p ,I N，p Less than the peak intensity I in the zeroth diffraction order M，p . As from Fig. 9 It can be inferred that in each principal refractive power D F , D M , D N The integrated intensity I F ,I M ,I N Approximately the same, which means that in the three main refractive powers D F , D M , D N The image quality in is comparable.

[0043] In the example shown, the lens 1 is made of a material that gives it a negligible small refractive chromatic aberration, i.e. its refractive index is substantially independent of the wavelength of light. Exemplary materials are glass, acrylic, silicone, hydrogel and PMMA. Alternatively, the lens 1 may be made of a different material.

[0044] The embodiments described so far have main regions Z of equal areai , the so-called Fresnel ring zone, where the following applies to the i-th main zone Z i The outer radius r i : r i = r1·i 0.5 (5)

[0045] In this embodiment of the lens 1, each main refractive power D F , D M , D N remains essentially independent of the optical pupil size, whether this is given by, for example, a pinhole stop or by the pupil of the eye. However, it may also be desirable for the individual main refractive powers D F , D M , D N Depending on the pupil size, this can be achieved, for example, by selecting the radius r according to i To achieve r i = r1·i z where z ≠ 0.5 (6)

[0046] For example, it can be expected that the near power D of a large pupil N Slightly larger near power D for small pupils N For this purpose, the main area Z i can have an area that is smaller (z<0.5) as the distance from the optical axis A increases. On the contrary, if, for example, the near power D N will decrease as the pupil size increases, then the main area Z i It may have a larger area as the distance from the optical axis A increases (z>0.5).

[0047] Fig.10a and 10b The results for monochromatic light with a wavelength of 550 nm are shown in Fig.10a ) and for polychromatic light with wavelengths from 450nm to 650nm ( Fig.10b ) is a through focus response for different values ​​of the parameter z, with a solid line 10 for a value z of 0.5, a dashed line 11 for a value z of 0.48, and a triangular line 12 for a value z of 0.52. As shown in the figure, the main refractive power D F , D M , D N , their correlation strength I F ,I M ,I N and their respective maximum values ​​vary with the parameter z; however, the intensity I F ,I M ,I N The sum of does not change.

[0048] Traditionally, in diffractive bifocal or trifocal lenses, the diffraction power of the zeroth diffraction order is used as the refractive power D F is considered to be advantageous because there is no diffraction chromatic aberration in the zeroth diffraction order. However, in one embodiment of the lens 1 disclosed herein, the diffraction power of the negative first diffraction order is now used as the distance refractive power D F , for example, to mimic the chromatic aberration of the eye lens, as described below.

[0049] Fig.11 shows the refractive power D of the human eye as a function of the wavelength λ of the light A (Based on: Charman WN, Jennings JAM (1976), "Objective measurement of longitudinal chromatic aberration in the human eye", Vision Research. 16: 999–1005, 051005). Fig.11 As shown, the longitudinal chromatic aberration of the human eye between 450nm and 650nm is about 1.3 diopters, wherein the refractive power of 450nm (blue light) is greater than that of 650nm (red light). Optik, Verlag Walterde Gruyter, 1993, the refractive power of the entire human eye is 58.8 diopters, and the refractive power of the eye lens is 20.2 diopters. Assuming that the chromatic aberration of the entire eye and the eye lens therein is proportional to the respective refractive powers, the chromatic aberration of the eye lens can be estimated as 1.3·20.2 / 58.8=0.447≈0.45 diopters according to the size, wherein blue light is refracted more strongly than red light.

[0050] Fig.12 Shows Figure 2 and 3 The main refractive power D of lens 1 for two wavelengths of 450nm (dashed line 13) and 650nm (solid line 14) is F , D M , D N . As from Fig.12 It can be inferred that, for the parameters chosen as an example, the negative first diffraction order (for the refractive power D F ) is 0.51 diopters (see Fig.12 The two left-hand peaks 15, 16 in the image are close to the values ​​given above for the eye lens. M ), the diffraction longitudinal chromatic aberration of lens 1 is zero (see Fig.12 The two intermediate peaks 17 and 18 in the positive first diffraction order (for the near refractive power D N ), the longitudinal chromatic aberration of diffraction is -0.51 diopters (see Fig.12The two right peaks 19, 20 in FIG. 1 , i.e., red light is refracted more strongly than blue light, which cancels out the chromatic aberration of the rest of the eye. This means that lens 1 approximates the chromatic aberration of the eye lens for long distances, has no chromatic aberration for medium distances, and approximates the chromatic aberration of the eye lens with the opposite sign for near distances.

[0051] The parameters of the lens 1 can be selected according to other estimates of the chromatic aberration of the eye itself, or adapted to the individual (previously measured) eye lens of the patient. For example, the lens can have a diffractive longitudinal chromatic aberration in the range of 0.1 to 1.2 diopters, for example in the range of 0.3 to 0.7 diopters, in particular - close to the values ​​estimated above - in the range of 0.35 to 0.55 diopters for the negative first diffraction order of light between 450 nm and 650 nm.

[0052] Of course, the refractive powers D1, D2 of the sub-areas 2, 3 are the same as those of the main areas Z. i The area components p1, p2 at and the associated main refractive power D of lens 1 F , D M , D N , ... may deviate from the illustrated embodiments, or may combine several of the presented embodiments. For example, the near refractive power D N and distance refractive power D F The difference between the intermediate power D and the intermediate power D may be in the range of 1 to 6 diopters, for example in the range of 2.0 to 4.5 diopters. M and distance refractive power D F The difference between the distance power D1 and the distance power D2 may be in the range of 1.4 diopters to 2 diopters, for example in the range of 1.6 diopters to 1.8 diopters. In addition, one of the refractive powers D1 or D2 of the respective sub-regions 2, 3 may be located, for example, at the far refractive power D1. F In the range of -2.5 to 2.5 diopters, in particular in the range of -2.0 to 2.0 diopters; alternatively or additionally, the other of the refractive powers D1 or D2 of the sub-regions 2, 3 may be, for example, in the near refractive power D N Around the range of -2.5 to 2.5 diopters, particularly around the range of -2.0 to 2.0 diopters.

[0053] The invention is not limited to the presented embodiments but comprises all variants, modifications and combinations coming within the scope of the appended claims.

Claims

1. A device having at least three main refractive powers (D F , D M , D N ) of a multifocal lens, comprising a plurality of concentric annular main areas (Z i ), each of the plurality of main areas is divided into inner and outer annular sub-areas (2, 3) having different refractive powers (D1, D2), and wherein, The lens (1) has no geometrical steps between all sub-regions (2, 3), Characterized in that the refractive powers (D1) of all inner sub-regions (2) are in each case equal to one another, and the refractive powers (D2) of all outer sub-regions (3) are in each case equal to one another, and that all inner and outer sub-regions (2, 3) share their respective main areas (Z i ), the area ratio is in the range from 30:70 to 70:

30.

2. The multifocal lens according to claim 1, characterized in that: All of the multiple main areas (Z i ) each have the same area.

3. The multifocal lens according to claim 1, characterized in that: The plurality of main regions (Z i ) increases or decreases monotonically from the inside to the outside.

4. The multifocal lens according to any one of claims 1 to 3, characterized in that: Each main area (Z i ) is less than 2.2πmm 2 , preferably less than πmm 2 , particularly preferably less than 2π / 3mm 2 .

5. The multifocal lens according to any one of claims 1 to 4, characterized in that: The area ratio is in the range of 40:60 to 60:40, preferably 50:

50.

6. The multifocal lens according to any one of claims 1 to 5, characterized in that: The lens (1) has 5 to 50 main regions (Z i ), preferably 10 to 20 main regions (Z i ).

7. The multifocal lens according to any one of claims 1 to 6, characterized in that: The lens (1) has far, intermediate and near refractive powers (D F , D M , D N ), wherein the near refractive power (D N ) and the distance refractive power (D F ) is in the range of from 1 to 6 diopters, preferably in the range of from 2.0 to 4.5 diopters.

8. The multifocal lens according to claim 7, characterized in that: The middle refractive power (D M ) and the distance refractive power (D F ) is in the range from 1.4 to 2 diopters, preferably in the range from 1.6 to 1.8 diopters.

9. The multifocal lens according to any one of claims 1 to 8, characterized in that: All sub-regions (2, 3) are combined to form a diffraction grating, and the diffraction grating generates the at least three main refractive powers (D F , D M , D N ), preferably exactly three diffractive principal powers (D F , D M , D N ).

10. The multifocal lens according to claim 7 and 9 or according to claim 8 and 9, characterized in that The distance refractive power (D F ) is produced by the negative first diffraction order of the lens (1).

11. The multifocal lens according to claim 10, characterized in that: The negative first diffraction order of the lens (1) for light between 450 nm and 650 nm has a diffractive longitudinal chromatic aberration in the range from 0.1 to 1.2 diopters, preferably in the range from 0.3 to 0.7 diopters, particularly preferably in the range from 0.35 to 0.55 diopters.

12. The multifocal lens according to any one of claims 1 to 11, characterized in that: The refractive power (D1) of the inner sub-region (2) or the refractive power (D2) of the outer sub-region (3) is within the range of the at least three main refractive powers (D F , D M , D N ) in the range of -2.5 to 2.5 diopters around the smallest of the at least three main refractive powers (D F , D M , D N ) in the range of -2.0 to 2.0 diopters around the smallest of the .

13. The multifocal lens according to any one of claims 1 to 12, characterized in that: The refractive power (D1) of the inner sub-region (2) or the refractive power (D2) of the outer sub-region (3) is within the range of the at least three main refractive powers (D F , D M , D N ) in the range of -2.5 to 2.5 diopters around the largest of the at least three main refractive powers (D F , D M , D N ) in the range of -2.0 to 2.0 diopters around the largest one.

14. The multifocal lens according to any one of claims 1 to 13, characterized in that: At least one inner or outer sub-region (2, 3) is subdivided into a plurality of local regions, the average refractive power of the plurality of local regions corresponding to the refractive power (D1, D2) of the corresponding sub-region (2, 3).

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