Progressive multifocal lens for myopia control and its manufacturing method

Abstract

There is provided a progressive multifocal lens provided with microlenses and having synchronous myopic defocus, the progressive multifocal lens including a surface with a varying dioptric power. The surface with a varying dioptric power (23) provides at least: - a designated distance portion (1) adapted for distance vision, and a fitting cross (17), in the upper section of the progressive multifocal lens (19); - a designated near portion (3) in the lower section of the progressive multifocal lens, the near portion (3) including a near reference point (7) having a near refractive dioptric power adapted for near vision; and - a designated intermediate zone (9) extending between the designated distance portion (1) and the designated near portion (3); wherein a plurality of microlenses (13) are superimposed on the surface (23) of the progressive multifocal lens (19). The microlenses (13) are excluded from all regions of the surface (23) located below an imaginary line (15) that extends from the nose to the temporal limit of the progressive multifocal lens (19) at a vertical coordinate (y) above the near reference point (7), where the vertical coordinate (y) is at a distance within the range between 1.5 mm and 3 mm above the near reference point (7). Additionally, a method of manufacturing a progressive multifocal lens (19) provided with microlenses (13) and having synchronous myopic defocus is defined. The method includes the following steps: - providing a progressive multifocal lens (19) having a surface with a varying dioptric power, wherein the surface with a varying dioptric power (23) provides at least a designated distance portion (1) in the upper section of the progressive lens, a designated near portion (3) in the lower section of the progressive multifocal lens (19), and a designated intermediate zone (9) extending between the designated distance portion (1) and the designated near portion (3). The distance portion (1) includes a distance reference point (5) and a fitting cross (17). The near portion (3) includes a near reference point (7). - superimposing a plurality of microlenses (13) on the surface (23) of the progressive multifocal lens (19), wherein the superimposition of the microlenses (13) is excluded from all regions of the surface (23) located below an imaginary line (15) that extends from the nose to the temporal limit of the progressive multifocal lens (19) at a vertical coordinate (y) above the near reference point (7), where the vertical coordinate (y) is at a distance within the range between 1.5 mm and 3 mm above the near reference point (7).

Description

[0001] The present invention relates to a progressive multifocal lens and a method for manufacturing a progressive multifocal lens. Additionally, the present invention relates to a computer program for establishing a numerical representation of a progressive multifocal lens, a non-volatile computer-readable storage medium having such a computer program, a data processing system for establishing a numerical representation of a progressive multifocal lens, and a computer-implemented method for establishing a numerical representation of a progressive multifocal lens.

[0002] In many East Asian countries, myopia has reached epidemic proportions, with some large urban centers reporting myopia prevalence rates approaching 100% among 18- to 19-year-olds (Jung S-K, Lee JH, Kakizaki H, et al., Prevalence of myopia and its association with body stature and educational level in 19-year-old male conscripts in Seoul, South Korea. Invest Ophthalmol Vis Sci. 2012;53:5579-5583 (“Prevalence of Myopia and Its Association with Body Stature and Educational Level in 19-Year-Old Male Conscripts in Seoul, South Korea,” Investigative Ophthalmology & Visual Science, 2012, Vol. 53, pp. 5579-5583)). It is estimated that there were approximately 2 billion myopic individuals globally in 2010, and some recent epidemiological models suggest that this number will increase to 5 billion by 2050 (Holden BA, Fricke TR, Wilson DA, et al., Global Prevalence of Myopia and High Myopia and Temporal Trends from 2000 through 2050. Ophthalmology 2016, 123:1036–1042 (“Global Prevalence of Myopia and High Myopia and Temporal Trends from 2000 through 2050,” Ophthalmology, 2016, Vol. 123, pp. 1036–1042)). In addition, there is an increasing trend among adolescents towards high myopia (defined as SER ≤ -5.00 D, where SER represents spherical equivalent refraction), which greatly increases the risk of eye diseases such as cataract, glaucoma, retinal detachment, and myopic maculopathy, all of which can lead to irreversible visual loss (Wong TY, Ferreira A, Hughes R, et al., Epidemiology and disease burden of pathologic myopia and myopic choroidal neovascularization: an evidence-based systematic review. Am J Ophthalmol 2014;157:9–25 (“Epidemiology and Disease Burden of Pathologic Myopia and Myopic Choroidal Neovascularization: An Evidence-Based Systematic Review,” American Journal of Ophthalmology, 2014, Vol. 157, pp. 9–25)).Epidemiological models predict that the global prevalence of high myopia will increase from approximately 300 million in 2010 to 1 billion in 2050 (Holden et al., 2016). This will inevitably lead to very high social costs in treating visual impairment and productivity loss.

[0003] Bifocal and progressive multifocal lenses have been clinically tested with the aim of reducing the accommodative lag during near vision tasks, which is considered one of the main causes of myopia progression in adolescents, and myopia progression in adolescents usually coincides with the start of school education. A recent Bayesian meta-analysis of clinical trials of progressive multifocal lenses for controlling myopia progression in adolescents has shown that PALs (progressive multifocal lenses) have a moderate effect in slowing myopia progression in the first year, with an average myopia delay rate of 28% for PALs in 10 randomized clinical trials (RCTs), but the effect weakens to 20% after 24 months and drops to only 15% after 36 months (Varnas Gu and Metcalfe (2020), in preparation). The design of PALs needs to be strengthened to enhance their efficacy in delaying myopia progression and to overcome the problem of the weakening of their efficacy over time.

[0004] It has been reported that bifocal contact lenses have achieved significant success in controlling myopia progression in RCTs. The bifocal contact lenses provide simultaneous myopic defocus over the fovea (Lam CS, Tang WC, Tse DY et al., Defocus Incorporated Soft Contact (DISC) lens slows myopia progression in Hong Kong Chinese schoolchildren: a 2-year randomised clinical trial. Br J Ophthalmol 2014;98:40-45 (“Defocus Incorporated Soft Contact (DISC) lens slows myopia progression in Hong Kong Chinese schoolchildren: a 2-year randomised clinical trial”, British Journal of Ophthalmology, 2014, Vol. 98, pp. 40-45); Cheng X, Xu J, Chehab K et al., Soft Contact Lenses with Positive Spherical Aberration for Myopia Control, Optom Vis Sci 2016;93:353-366 (“Soft Contact Lenses with Positive Spherical Aberration for Myopia Control”, Optometry and Vision Science, 2016, Vol. 93, pp. 353-366); Aller TA, Liu M and Wildsoet CF, Myopia Control with Bifocal Contact Lenses: A Randomized Clinical Trial, Optom Vis Sci 2016;93:344-352 (“Myopia Control with Bifocal Contact Lenses: A Randomized Clinical Trial”, Optometry and Vision Science, 2016, Vol. 93, pp. 344-352);Ruiz-Pomeda A, Pérez-Sánchez B, Valls I, Prieto-Garrido FL, Gutierrez-Ortega R, Villa-Colar C, MiSight Assessment StudySpain(MASS): A 2-year randomized clinical trial, Graefe’s Archive for Clinicaland Experimental Ophthalmology 256, 1011–1021, 2018(“Spain MiSight Assessment Study (MASS): A 2-year randomized clinical trial, Graefe's Archive for Clinical and Experimental Ophthalmology”, Graefe's Archive for Clinical and Experimental Ophthalmology, 2018, Vol. 256, pp. 1011-1021); Sankaridurg P, BakarajuRC, Naduvilath T, Chen X, Weng R, Tilia D, XuP, Li W, Conrad F, Smith EL III and Ehrmann K, Myopia control with novel central andperipheral plus contact lenses and extended depth offocus contact lenses: 2year results from a randomised clinical trial. Ophthalmic Physiol Opt2019; 39(4):294–307(“Myopia control with novel central and peripheral plus contact lenses and extended depth of focus contact lenses: 2-year results from a randomised clinical trial”, Ophthalmic and Physiological Optics, 2019, Vol. 39, No. 4, pp. 294–307); Chamberlain P, Peixoto-De-Matos SC, LoganNS, Ngo C, Jones D, Young G, A 3-yearRandomized Clinical Trial ofMiSight Lenses for Myopia Control. Optom VisSci. 2019;96(8):556–67(“3-Year Randomized Clinical Trial of the MiSight Contact Lens for Myopia Control”, Optometry and Vision Science, 2019, Vol. 96, No. 8, pp. 556-67)). Most of these studies used center distance vision design contact lenses and assumed that these contact lenses provided a stop signal for eye growth through their effect on peripheral vision, which in myopic eyes often presents as a relative hyperopic shift (e.g., Walline JJ, Myopia Control: A Review. Eye & Contact Lens. Volume 42, Number 1, January 2016, 3-8(“Myopia Control: A Review”, Eye & Contact Lens, January 2016, Vol. 42, No. 1, pp. 3-8)). However, this theory contradicts a series of clinical study results, which show that there is little correlation between the progression rate of myopia and the peripheral hyperopic shift (Mutti D.O., Sinnott L.T., Mitchell G.L., Jones-Jordan L.A., Moeschberger M.L., Cotter S.A., Kleinstein R.N., Manny R.E., Twelker J.D., Zadnik K. (2011), Relative Peripheral Refractive Error and the Risk of Onset and Progression of Myopia in Children, Invest. Ophthal-mol. Vis. Sci., 52(1), 199–205(“Relative Peripheral Refractive Error and the Risk of Onset and Progression of Myopia in Children”, Investigative Ophthalmology & Visual Science, Vol. 52, No. 1, pp. 199–205); Sng C.C.A., Lin X.-Y., Gazzard G., Chang B., Dirani M., Chia A., Selvaraj P., Ian K., Drobe B., Wong T.-Y., and Saw S.-M. (2011), Peripheral Refraction and Refractive Error in Singapore Chinese Children, Invest. Ophthalmol. Vis. Sci., 52(2), 1181–1190(“Peripheral Refraction and Refractive Error in Singapore Chinese Children”, Investigative Ophthalmology & Visual Science, Vol. 52, No. 2, pp. 1181–1190);Hasebe S, Jun J, Varnas SR, Myopia control with positively aspherized progressive addition lenses: a 2-year, multicentre, randomized, controlled trial. Invest Ophthalmol Vis Sci. 2014;55:7177–7188 (“Myopia control with positively aspherized progressive addition lenses: a 2-year, multicentre, randomized, controlled trial”, Investigative Ophthalmology & Visual Science, 2014, Vol. 55, pp. 7177–7188). In addition, in a large-scale study involving 2700 Chinese children (Atchison D.A., Li S.-M., Li H., Li S.-Y., Liu L.-R., Kang M.-T., Meng B., Sun Y.-Y., Zhan S.-Y., Mitchell P., and Wang N., Relative peripheral hyperopia does not predict development and progression of myopia in children. Invest Ophthalmol Vis Sci.; 2015;56:6162–6170 (“Relative peripheral hyperopia does not predict development and progression of myopia in children”, Investigative Ophthalmology & Visual Science, 2015, Vol. 56, pp. 6162–6170)) - there was an inverse correlation – children with higher hyperopic relative peripheral refraction (RPR) had slower myopia progression than children with lower hyperopic RPR. Thus, the inventors hypothesized that the efficacy of bifocal contact lenses in retarding axial elongation of the eye in myopic children depends on the delivery of synchronous myopic defocus to the fovea rather than the peripheral retina.

[0005] The difficulty lies in how to deliver such synchronous myopic defocus in an eyeglass lens in a manner that will not affect the acceptance of such a lens by young patients. A conceptual solution to this problem was proposed in US10,268,050B2 by applying an annular or circular microlens array to the surface of a spherical eyeglass lens. Using an annular microlens array, a small area centered on the optical center of the eyeglass lens and having a diameter of approximately two pupil diameters is free of microlenses to increase wearer comfort and aid acceptance. A similar eyeglass lens with microlenses was disclosed in WO 2019 / 166657 A1.

[0006] WO 2019 / 166654 A1 discloses an ophthalmic lens having an annular microlens array centered on the optical center of the ophthalmic lens, wherein the central portion of the ophthalmic lens is free of microlenses. The ophthalmic lens disclosed in WO 2019 / 166654 A1 can be implemented as a progressive multifocal lens. For example, it is known from WO 2018 / 100012 A1 to use a progressive multifocal lens to reduce accommodation lag, which discloses a special progressive multifocal lens having a high negative average power gradient near the near vision portion to reduce accommodation lag.

[0007] WO 2020 / 113212 A1 discloses an ophthalmic lens having a scattering center and two clear apertures without a scattering center. The scattering center can be a protrusion on the surface of the ophthalmic lens, the size of these protrusions being in the range from 0.001 mm to 1 mm, and the ophthalmic lens can be a progressive multifocal lens, one of its clear apertures being located in the near vision portion. The ophthalmic lens can also include microlenses, wherein the microlenses form an annular array and are absent from the clear apertures. Then, one of the clear apertures is located at the center of the array, while the other can be located in the near vision portion, in which the clear aperture forms a discontinuity of the annular array. However, there are still some regions of the near vision portion covered by microlenses in WO 2020 / 113212 A1. The inventors of the present invention have evaluated ophthalmic lenses having an annular microlens array that makes a small area centered on the optical center of the ophthalmic lens transparent and have found that such ophthalmic lenses may create discomfort and eye fatigue when viewing near objects through the central depression of the microlenses. Additionally, the clear aperture in the near vision portion overlaps with the peripheral region of the progressive ophthalmic lens, which will make it difficult to use the concept of WO 2020 / 113212 A1, where the progressive multifocal lens has a high negative average power gradient near the near vision portion, as disclosed in WO 2018 / 100012 A1, because the near vision portion of those progressive multifocal lenses is typically narrower than that of common progressive multifocal lenses.

[0008] According to WO 2019 / 166654 A1, a first object of the present invention is to provide a progressive multifocal lens provided with microlenses and having synchronous myopic defocus, which helps to avoid discomfort and eye fatigue and can be easily combined with a high negative average power gradient near the near vision portion.

[0009] A second object of the present invention is to provide a method for manufacturing a progressive multifocal lens provided with microlenses and having synchronous myopic defocus, which helps to avoid discomfort and eye fatigue and can be easily combined with a high negative average power gradient near the near vision portion.

[0010] A third object of the present invention is to provide a data processing system and a computer program for establishing a numerical representation of a progressive multifocal lens provided with microlenses and having synchronous myopic defocus, and a computer-implemented method for establishing a numerical representation of a progressive multifocal lens provided with microlenses and having synchronous myopic defocus, which progressive multifocal lens helps to avoid discomfort and eye fatigue and can be easily combined with a high negative average power gradient near the near-vision portion.

[0011] The first object is achieved by the progressive multifocal lens according to the present invention, the second object is achieved by the method according to the present invention, and the third object is achieved by the computer program according to the present invention, the non-volatile storage medium according to the present invention, the data processing system according to the present invention, and the computer-implemented method according to the present invention. The following description includes advantageous developments of the present invention.

[0012] The following definitions are used within the scope of this description:

[0013] Progressive multifocal lens

[0014] A progressive multifocal lens (PAL) (sometimes also referred to as a progressive power lens (PPL) or a varifocal lens) is a lens with a varying power, i.e., an ophthalmic lens in which the focusing power varies smoothly over part or all of its area without discontinuities. The progressive multifocal lens is designed to provide more than one focusing power, where two reference points of the focusing power are typically designed to provide presbyopia correction and clear vision from distance to near vision (DIN ISO 13666:2019, section 3.7.8).

[0015] Distance portion

[0016] The distance portion refers to that part of the progressive multifocal lens that has a refractive power for distance vision (DIN ISO 13666:2019, section 3.15.1). Throughout this specification, the refractive power for distance vision is referred to as the distance refractive power.

[0017] Distance reference point

[0018] The distance reference point is the point on the front surface of the ophthalmic lens where the verification power for the distance portion is applied (DIN ISO 13666:2019, section 3.2.20), where the verification power is the refractive power of the ophthalmic lens specifically calculated by the manufacturer and provided as a reference for lensometer verification.

[0019] Near-vision portion

[0020] The near-vision portion refers to that part of the progressive multifocal lens that has a refractive power for near vision (DIN ISO 13666:2019, section 3.15.3).

[0021] Near vision reference point

[0022] The near vision reference point is the point on the front surface of an ophthalmic lens at which the verification power for the near vision portion is applied (DIN ISO 13666:2019, section 3.2.21), where the verification power is the refractive power of the ophthalmic lens that is specifically calculated by the manufacturer and provided as a reference for lensmeter verification.

[0023] Intermediate zone

[0024] The term "intermediate zone" shall designate the part of a power-varying lens, such as a progressive addition lens, that provides the intended variation in spherical vertex power and cylindrical vertex power. Thus, in the context of the present invention, the term "intermediate zone" denotes the zone in a progressive addition lens where the surface astigmatism is low and the surface power varies from the distance vision portion to the near vision portion.

[0025] Addition

[0026] The addition specifies the difference between the vertex power in the near vision portion of a progressive addition lens and the vertex power in the distance vision portion of the progressive addition lens (DIN ISO 13666:2019, section 3.16.3), where the vertex power represents the reciprocal of the paraxial back focal length measured in meters of the image-side focal point.

[0027] Refractive power

[0028] The term "refractive power" is the collective term for the focusing power and the prismatic power of an ophthalmic lens. The term "focusing power" is in turn the collective term for the spherical vertex power of an ophthalmic lens (which brings a paraxial parallel beam of light to a single focal point and which is usually accounted for in a prescription by the "sphere" value or the abbreviation "sph") and the cylindrical vertex power of an ophthalmic lens (which brings a paraxial parallel beam of light to two separate focal lines that are mutually at right angles (DIN ISO 13666:2019, section 3.10.2) and which is usually accounted for in a prescription by the "cylinder" value or the abbreviation "cyl"). "Vertex power" is the reciprocal of the paraxial vertex focal length (DIN ISO 13666:2019, section 3.10.7). Within the scope of this specification, a beam of light is considered to be a paraxial beam of light if the diameter of the beam does not exceed 0.05 mm, especially 0.01 mm.

[0029] Power-varying surface

[0030] A surface with varying dioptric power is a surface on which the surface dioptric power varies smoothly over part or all of its area without discontinuities (DIN ISO 13666:2019, section 3.4.10), where the surface dioptric power is the local ability of the finished surface to change the vergence of a light beam incident at that surface (DIN ISO 13666:2019, section 3.10.4). In the case of progressive multifocal lenses, the surface with varying dioptric power can also be referred to as the "progressive surface".

[0031] Actual wearing position

[0032] The actual wearing position refers to the position (including orientation) of an ophthalmic lens relative to the eye and the face during wearing (DIN ISO 13666:2019, section 3.2.36).

[0033] Numerical representation of an ophthalmic lens

[0034] In the context of the present invention, the numerical representation of an ophthalmic lens is a mathematical description of the ophthalmic lens for optimization by means of a computer-implemented method and for the production of ophthalmic lenses by means of a CNC process.

[0035] Optimizing an ophthalmic lens

[0036] Within the scope of the present invention, optimizing an ophthalmic lens means performing a computer-aided process in which the numerical representation of the ophthalmic lens is described by means of at least one parametric function (typically by means of a plurality of parametric functions) that describes the numerical representation, where the target characteristics to be achieved by the ophthalmic lens are predefined, and where a merit function is specified, the value(s) of which specify the deviation of the characteristics achieved by the current parameter value(s) of the (plurality of) parametric function(s) from the target characteristics, and changing the parameter value(s) of the (plurality of) parametric functions until the value(s) of the target function satisfy a termination criterion, thereby terminating the change of one or more parameter values.

[0037] Prescription

[0038] The term "prescription" denotes a summary that prescribes the refractive power required for correcting a diagnosed refractive error in the form of suitable values. In the case of spherical power, the prescription may contain the "sph" value of the spherical lens. In the case of astigmatic power, the prescription may contain the "cyl" value of the cylindrical lens and the "axis" value of the axis, and in the case of prism power, the prescription may contain the prism value. Moreover, the prescription may contain other values, such as the "add" value in the case of progressive ophthalmic lenses, which specifies the difference between the back vertex power of the near vision part of the ophthalmic lens and the back vertex power of the far vision part of the ophthalmic lens. The "PD" value of the interpupillary distance may also be included in the prescription.

[0039] Target design

[0040] In the context of the present invention, the target design is a specification of the distribution of image aberrations on an ophthalmic lens or a specification of the surface characteristics of an ophthalmic lens that should be achieved during the optimization process. In the first case, an optical target design is mentioned, while in the second case, a surface target design is mentioned. Accordingly, the optical target design is a specification of the distribution of image aberrations (e.g., residual astigmatism, residual spherical aberration, prism, horizontal symmetry, distortion, or higher-order aberrations such as coma) over or outside the entire ophthalmic lens in the beam path of the spectacle wearer. Additionally, the optical target design may include specifications of the residual astigmatism and residual spherical aberration at a reference point (e.g., a distance design reference point or a near design reference point), or a specification of the add power on the measurement beam path of a measuring device (e.g., the beam path of a lensometry device). In contrast, the surface target design specifies the surface characteristics of the free-form surface to be formed that should be achieved during the optimization process, such as surface power, surface astigmatism, and the axis position of the astigmatism. Here, the surface power is a measure of the ability of a surface section around the optimization point to change the vergence (the refractive index of the ophthalmic lens material divided by the radius of curvature of the wavefront) of the light beam incident on that surface section. The surface astigmatism at the optimization point represents the difference in surface power on the principal meridians at the optimization point of the surface. If the following text does not specifically mention an optical target design or a surface target design, but only mentions a target design, the term "target design" shall always include both types of target designs.

[0041] RMS blur

[0042] In the context of this specification, RMS blur should be considered the physiological blur experienced by a wearer of a progressive multifocal lens due to the mean square spherical error (SphErr) and the mean square astigmatic error (AstErr) added together with appropriate weights A, B to reflect the way the human visual system integrates such optical errors (RMS = Sqrt(A·SphErr 2 +(B·AstErr / 2) 2 ). The values of the weights A, B can be in the range between 0 and 1, particularly between 1 / 2 and 1. An example of calculating RMS blur is RMS = Sqrt(SphErr 2 +(AstErr / 2) 2 ) with weights of 1 and 1 / 2. RMS blur is calculated based on ray tracing of a model lens using a hypothetical object field. Additionally, for the calculation of RMS blur, it is assumed that the wearer can accommodate up to a power error of 1.00 D.

[0043] Microlens

[0044] In the context of the present invention, the term "microlens" refers to a small convex structure in a lens of approximately spherical shape, which is provided on the surface of an eyewear lens and whose lateral dimension is at least one order of magnitude smaller than the dimension of the eyewear lens itself.

[0045] Fitting cross

[0046] The fitting cross indicates the fitting point of the eyewear lens, i.e., the point on the front surface of the eyewear lens or blank specified by the manufacturer for positioning the eyewear lens in front of the eye (DIN ISO 13666:2019, section 3.2.24).

[0047] Elliptical microlens

[0048] In the context of the present invention, the term "elliptical microlens" refers to the profile of the microlens on the surface over which it is superimposed. Although the microlens is a segment of a sphere, if the profile of the microlens on the surface is elliptical, the microlens is called elliptical. The adjective "elliptical" is used to characterize a profile that satisfies the following equation in a Cartesian coordinate system: x 2 / a 2 +y 2 / b 2 = 1 (where a, b, c > 1, and the case a = b is not excluded). The case a = b gives a circle, which in the context of the present invention is considered a special case of an ellipse. Thus, a microlens with a circular profile is considered a special case of an elliptical microlens.

[0049] Working eyewear lens

[0050] The term "working eyewear lens" is used to indicate an eyewear lens given in numerical representation, which has at least one parameterized surface to be optimized during an optimization process.

[0051] Superimposition

[0052] In the context of the present invention, the term "superimposition" means to impose, place, or set above, over, or on top of something else.

[0053] According to a first aspect of the present invention, there is defined a progressive multifocal lens provided with microlenses and having synchronous myopic defocus. The progressive multifocal lens has a surface with a varying dioptric power. The surface with the varying dioptric power provides at least a designated distance portion adapted for distance vision in an upper section of the progressive multifocal lens, a designated near portion in a lower section of the progressive multifocal lens (where the near portion includes a near reference point having a near refractive dioptric power adapted for near vision), and a designated intermediate zone extending between the designated distance portion and the designated near portion. The near reference point may define the apex of the near portion and demarcate this portion in the vertical direction. A plurality of microlenses are superimposed on the surface of the progressive multifocal lens. According to the present invention, the microlenses are excluded from all regions of the surface located below an imaginary line that extends from the nose to the temporal limit of the progressive multifocal lens at a vertical coordinate above the near reference point, where the value of the coordinate lies within the range between 1.5 mm and 3 mm. In many cases, a value between 1.8 mm and 2.2 mm is suitable, for example, a value of 2 mm.

[0054] Excluding the microlenses from the lower section of the progressive multifocal lens serves two purposes: (1) facilitating compliance with the intended use of the near portion for near vision, and (2) maintaining the beneficial effect of negative asphericity of the near portion to reduce accommodation lag.

[0055] Microlens array

[0056] A microlens array is a systematic arrangement of microlenses over an area of the array region as referred to in the context of this specification. For example, this systematic arrangement can be achieved by a regular or uniform distribution of the microlenses over the array region.

[0057] The present invention is based on the following considerations:

[0058] In a clinical trial of approximately 80 children at the Hong Kong Polytechnic University (HKPolyU) (with a similar number in the control group), a spectacle lens design with a ring of microlenses was successfully tested. The results showed that after 24 months of follow-up, compared with the control group, the progression of myopia was slowed by 52% and the axial elongation of the eye was slowed by 62%, with a dropout rate < 15% (Lam CSY, Tang WC, Tse DYY, Lee RPK, Chun RKM, Hasegawa K et al., Defocus incorporated multiple segments (DIMS) spectacle lenses slow myopia progression: A 2-year randomised clinical trial. Br J Ophthalmol. 2020;104(3):363–8 (“Multizone incorporated defocus (DIMS) spectacle lenses slow myopia progression: A 2-year randomised clinical trial”, British Journal of Ophthalmology, 2020, Vol. 104, No. 3, pp. 363 - 8)). Testing of this type of spectacle lens has shown that long-term wear is very uncomfortable and there is a strong motivation to always view through the central area of the spectacle lens that avoids the microlenses. This means that this area of the spectacle lens is used for central distance vision and near vision most of the time, and when the eye drifts into the area covered by the microlenses, synchronous myopic defocus is only intermittently transmitted to the fovea. This should not be a problem, as it is well known that myopic defocus is more powerful than hyperopic defocus in terms of temporal integration and its effect on eye length evolution (Wallman J and Winawer J, Homeostasis of Eye Growth and the Question of Myopia. Neuron 2004;43:447–468 (“Homeostasis of eye growth and the question of myopia”, Neuron, 2004, Vol. 43, pp. 447–468)). Animal experiments have shown that wearing negative lenses that provide hyperopic defocus throughout the day can be offset by four 2-minute periods of positive spectacle lens wear (myopic defocus) during the day (Zhu X., Winawer J. and Wallman J. (2003), The potency of myopic defocus in lens-compensation. Invest. Ophthalmol. Vis. Sci. 44, 2818-2827 (“The potency of myopic defocus in lens-compensation”, Investigative Ophthalmology & Visual Science, Vol. 44, pp. 2818-2827)). This suggests that intermittent exposure to synchronous myopic defocus can be sufficient to provide a stop signal for the axial elongation of the eye.

[0059] In the progressive multifocal lens disclosed in WO 2019 / 166654 A1, an annular microlens array is also present in the near vision portion. Since the microlenses provide a positive addition power above the near reference point (NRP), the presence of the microlenses may reduce the accommodation response, as has been shown in accommodation studies with bifocal contact lenses (Gong CR, Troilo D, and Richdale K, Accommodation and Phoria in Children Wearing Multifocal Contact Lenses. Optom Vis Sci 2017;94:353 - 360 (“Accommodation and phoria in children wearing multifocal contact lenses”, Optometry and Vision Science, 2017, Vol. 94, pp. 353 - 360)). Therefore, the inventors of the present invention concluded that the microlenses should be excluded from the lower portion of the progressive lens dedicated to near vision in order to maintain the positive effect of the addition power on the accommodation response. Moreover, due to the prismatic variation between the microlenses, the microlenses create multiple images on the fovea. Thus, for near vision tasks, when viewing through the area covered by the microlenses, one needs to accommodate and focus on the images from the surface areas between the microlenses, which provide a stable single image. In this case, due to the myopic defocus created by providing the microlenses in the central visual field, myopic eyes often experience binocular fatigue and an increase in accommodation lag. Although there is a clear aperture without microlenses in the near vision portion of WO 2020 / 113212 A1, some areas of the near vision portion, especially in the periphery, are still covered by microlenses with a relatively positive power, which will provide a stimulus to relax accommodation and thus increase the accommodation lag in the images created by the gaps between the microlenses.

[0060] By a virtual line extending from the nasal portion to the temporal limit of the progressive multifocal lens at a vertical coordinate where all areas are above the near reference point of the progressive multifocal lens of the present invention (where the vertical coordinate is located at a distance within the range selected between 1.5 mm and 3 mm above the near reference point, especially having a value of about 2 mm), it can be ensured that the microlenses are not used during the near vision task. This is because 2 mm approximately corresponds to the pupil radius above the near reference point. Thus, the entire near vision portion and adjacent areas that may be used during the near vision task are free of microlenses, while the microlenses still exist in other parts of the progressive multifocal lens, enabling the progressive multifocal lens to deliver synchronous myopic defocus for other visual tasks. Therefore, compared with the progressive multifocal lenses disclosed in WO 2019 / 166654 A1 and WO 2020 / 113212 A1, the progressive multifocal lens of the present invention is more comfortable, while still being able to effectively deliver myopic defocus and more effectively reduce accommodation lag.

[0061] In the progressive multifocal lens of the present invention, there may be peripheral zones on the left and right sides of the designated near vision portion, and in these peripheral zones, the average additional optical power does not exceed 0.125 D. Then, the spacing between the peripheral zones on the left and right sides of the near vision portion is 25 mm or less, particularly 20 mm or less. This provides a large average additional optical power gradient in the regions adjacent to the near vision portion on the left and right sides. This large gradient is particularly effective in reducing accommodation lag.

[0062] In an advantageous development of the present invention, in those parts of the progressive multifocal lens where microlenses are not excluded, microlenses are present in regions where the RMS (root mean square) blur of the surface exceeds a threshold of 0.25 D. These regions can be covered with microlenses without causing significant disruption to foveal vision. The outer side of this region can be limited by a circle with a diameter of approximately 35 mm, which approximately corresponds to the maximum eye rotation that can be comfortably maintained for a perceptible length of time, and in the lower section of the progressive multifocal lens, this region is limited by a vertical coordinate that is near the pupil radius above the near vision reference point of the progressive multifocal lens.

[0063] The power-varying surface can typically provide a designated far vision portion located in the upper section of the progressive multifocal lens. The far vision portion is suitable for distant vision and includes a far vision reference point having a far vision refractive power. Thus, the near vision refractive power at the near vision reference point is given by adding a first additional optical power to the far vision refractive power, and each microlens provides a second additional optical power that is at least as high as, preferably higher than, the first additional optical power. Typically, the first additional optical power is 1.50 or higher. If the first additional optical power is, for example, 1.50 D, then the second additional optical power is 1.50 D or higher, and if the first additional optical power is 2.00 D, then the second additional optical power is 2.00 D or higher. Preferably, the second additional optical power is at least 0.5 D higher than the first additional optical power. Thus, in an example where the first additional optical power is 1.50 D, the second additional optical power will be 2.00 D or higher, and in an example where the first additional optical power is 2.00 D, the second additional optical power will be 2.50 D or higher. However, the second additional optical power can even be at least 1.0 D higher than the first additional optical power. By making the second additional optical power higher than the first additional optical power, myopic defocus can be ensured.

[0064] Typically, a fitting cross is provided on the progressive multifocal lens. Advantageously, the micro-lenses are distributed over a region extending on a semi-circular ring in the distance vision portion, the smaller radius of the semi-circular ring being between 4 mm and 6 mm and the larger radius being between 17 mm and 18 mm, wherein the semi-circular ring is centered on the fitting cross (FC). The outer radius approximately corresponds to the maximum eye rotation that can be comfortably maintained for a perceptible length of time. Thus, providing micro-lenses outside the outer radius would be of little use. Additionally, an inner radius of 5 mm allows clear foveal distance vision. Further, the micro-lenses need to be excluded from the interior of the distance power measurement circle centered on the distance reference point and having a radius of 4 mm. The distance reference point in the progressive lens is typically placed between 2 mm and 6 mm above the fitting cross. In this embodiment of the progressive multifocal lens of the present invention, the micro-lenses located in the distance vision portion effectively provide a region of myopic defocus.

[0065] In the progressive multifocal lens of the present invention, the micro-lenses superimposed on the surface may form a micro-lens array covering an array region on the surface, wherein the proportion of the array region covered by the micro-lenses is at least 30%. In an animal experiment on chicks, a coverage rate of approximately 33% has provided a sufficient stop signal to prevent the development of myopia, and the eyes of the chicks were subjected to competing myopic defocus and hyperopic defocus with a spatial proportion of the corresponding defocus region of 33:67 (Tse DY and To C-H, Graded Competing Regional Myopic and Hyperopic Defocus Produce Summated Emmetropization Set Points in Chick, Invest Ophthalmol Vis Sci. 2011;52:8056–8062 (“Graded Competing Regional Myopic and Hyperopic Defocus Produce Summated Emmetropization Set Points in Chick”, Investigative Ophthalmology & Visual Science, 2011, Vol. 52, pp. 8056–8062)). However, the coverage rate can be higher, such as at least 40% or at least 50%.

[0066] In an advantageous development of the present invention, the microlenses superposed on said surface form a microlens array, wherein each microlens not located at the edge of the array has at least four neighbouring microlenses, the distance between the centres of adjacent microlenses being in the range between 1.3 mm and 2.0 mm, and each microlens is elliptical, the arithmetic mean of its semi-major axis and semi-minor axis being in the range between 0.25 mm and 0.75 mm, in particular in the range between 0.4 mm and 0.65 mm. It should be noted that the semi-major axis and the semi-minor axis can be equal, such that in the present specification, the term "elliptical microlens" should also include circular microlenses as a limiting case. Such a microlens array allows the area coverage rate (i.e., the proportion of the array area covered by microlenses) to be between 30% and 60%, which effectively provides myopic defocus while keeping the wearer's discomfort within tolerable limits.

[0067] In the progressive multifocal lens of the present invention, it is advantageous that the surface on which the microlenses are superposed is a surface with a changing dioptric power. Providing microlenses on the other surface would cause the microlenses to produce astigmatism in the peripheral region of the progressive multifocal lens. The astigmatic imaging of the microlenses would not provide clear myopic defocus for the eye. In fact, the astigmatic imaging of the microlenses can provide conflicting focal images depending on the orientation of the object being viewed.

[0068] According to a second aspect of the present invention, a method for manufacturing a progressive multifocal lens provided with microlenses and having synchronous myopic defocus is defined. The method at least comprises the following steps:

[0069] - Providing a progressive multifocal lens having a surface with a changing dioptric power, wherein the surface with a changing dioptric power at least provides a designated distance portion suitable for distance vision located in the upper section of the progressive multifocal lens, a designated near portion located in the lower section of the progressive multifocal lens, and a designated intermediate zone extending between the designated distance portion and the designated near portion, the near portion including a near reference point having a near refractive dioptric power suitable for near vision. The near reference point can define the vertex of the near portion and demarcate this portion in the vertical direction.

[0070] - Superposing a plurality of microlenses (13) on the surface of the progressive multifocal lens.

[0071] According to the present invention, when superposing the microlenses, the superposition of the microlenses is excluded from all regions of the surface located below an imaginary line that extends from the nose to the temporal limit of the progressive multifocal lens at a vertical coordinate above the near reference point, wherein the vertical coordinate is in the range between 1.5 mm and 3 mm above the near reference point. In many cases, a distance of the vertical coordinate in the range between 1.8 mm and 2.2 mm, for example, a distance of 2 mm, is suitable.

[0072] The method of the present invention allows for the manufacture of progressive multifocal lenses that achieve the advantages described for the progressive multifocal lenses of the present invention.

[0073] The power change surface can have peripheral zones on the left and right of the designated near vision portion, in which the average addition power does not exceed 0.125 D, and the spacing between the peripheral zones on the left and right of the near vision portion can be 25 mm or less, particularly 20 mm or less. This provides a large average addition power gradient in the regions adjacent to the near vision portion on the left and right. This large gradient is particularly effective in reducing accommodation lag.

[0074] A number of microlenses can be superimposed such that in those parts of the progressive multifocal lens where the microlenses are not excluded, the microlenses are present in zones where the RMS blur of the surface exceeds a threshold of 0.25 D. These zones can be covered with microlenses without significantly disrupting foveal vision. The outside of this region can be limited by a circle with a diameter of 35 mm, which approximately corresponds to the maximum eye rotation that can be comfortably maintained for a perceptible length of time, and in the lower section of the progressive multifocal lens, this region is limited by a vertical coordinate above the near vision reference point of the progressive multifocal lens, where the distance of this vertical coordinate from the near vision reference point is approximately equal to the pupil radius.

[0075] The near vision refractive power at the near vision reference point can be given by the far vision refractive power plus a first addition power, and each superimposed microlens provides a second addition power that is at least as high as the first addition power, preferably higher than the first addition power. Typically, the first addition power is 1.50 or higher. If the first addition power is, for example, 1.50 D, then the second addition power is 1.50 D or higher, and if the first addition power is 2.00 D, then the second addition power is 2.00 D or higher. Preferably, the second addition power is at least 0.5 D higher than the first addition power and can be at least 1.0 D higher than the first addition power. Thus, in an example where the first addition power is 1.50 D, the second addition power will be 2.00 D or higher, and in an example where the first addition power is 2.00 D, the second addition power will be 2.50 D or higher. By making the second addition power higher than the first addition power, myopic defocus can be ensured. The second addition power can be the same for each microlens or can vary between microlenses, as long as the second addition power is at least as high as the first addition power.

[0076] In the method of the present invention, a fitting cross can be provided on the progressive multifocal lens. Then, microlenses can be distributed over a region forming a semi-circular ring in the distance vision portion, the smaller radius of the semi-circular ring being between 4 mm and 6 mm and the larger radius being between 17 mm and 18 mm and the semi-circular ring being centered on the fitting cross (FC). The outer radius approximately corresponds to the maximum eye rotation that can be comfortably maintained for a perceptible length of time. Thus, providing microlenses outside the outer radius will not provide any benefit. Additionally, an inner radius of 5 mm allows clear foveal distance vision. Thus, in this development of the method of the present invention, the microlenses are superimposed on the following region of the distance vision portion: the region effectively provides myopic defocus and still provides some comfort to the wearer, which increases the acceptance of the progressive multifocal lens established according to the computer-implemented method.

[0077] In the method of the present invention, the microlenses can be superimposed on the surface in the form of a microlens array covering an array region on the surface, wherein the superimposition is done such that the proportion of the array region covered by the microlenses is at least 30%. A coverage rate of at least 30% has provided sufficient stop signals to inhibit the progression of myopia. However, the coverage rate can be higher, for example, at least 40% or at least 50%.

[0078] According to a further development of the method, a number of microlenses are superimposed on the surface such that the number of microlenses forms a microlens array, wherein each microlens not located at the edge of the array has at least four neighboring microlenses. The distance between the centers of adjacent microlenses is in the range between 1.3 mm and 2.0 mm, and each microlens is elliptical, the arithmetic mean of its semi-major axis and semi-minor axis being in the range between 0.25 mm and 0.75 mm, particularly in the range between 0.4 mm and 0.65 mm. Such a microlens array allows the area coverage rate (i.e., the proportion of the array region covered by the microlenses) to be between 30% and 60%, which effectively provides stop signals for the development of myopia while keeping the discomfort of the wearer tolerable.

[0079] According to the method of the present invention, the surface on which the microlenses are superimposed can be the surface of power variation. Superimposing microlenses on another surface will cause the microlenses to produce astigmatism in the peripheral region of the progressive multifocal lens. The astigmatic imaging of the microlenses will not provide a clear stop signal for the development of myopia in the eye. In fact, the astigmatic imaging of the microlenses can provide an opposing signal for emmetropia depending on the orientation of the edge of any viewed object, since the focal position of the image varies with the orientation of the cylinder axis position.

[0080] Providing a progressive multifocal lens and superimposing microlenses on the surface of the progressive multifocal lens can be achieved by using a numerical representation of the progressive multifocal lens. A mold is then fabricated based on the numerical representation of the progressive multifocal lens, and the progressive multifocal lens is fabricated by using the mold through a molding or casting process. As a further alternative (which does not require a numerical representation of the progressive multifocal lens), providing a progressive multifocal lens and superimposing microlenses on the surface of the progressive multifocal lens can be accomplished by providing a progressive multifocal lens without microlenses, applying additional material on the surface of the progressive multifocal lens, and shaping the additional material to form microlenses. Adding the additional material and shaping the additional material can be accomplished by various means. For example, a thermal reflow method, imprinting, microdroplet jetting, or a MEMS-based method can be used. The following article describes the use of these methods to form microlenses: W Yuan, “Fabrication of Microlens Array and Its Application: A Review” in J. Mech. Eng. (2018) 31:16. Accordingly, for further details regarding the thermal reflow method, imprinting, microdroplet jetting, and MEMS-based methods, reference is made to this document.

[0081] According to a third aspect of the present invention, a computer program is defined for establishing a numerical representation of a progressive multifocal lens provided with microlenses and having synchronous myopic defocus. The computer program includes program code having instructions which, when executed by a computer, cause the computer to at least:

[0082] - Obtain a distance refractive power suitable for distance vision in an upper portion of the progressive multifocal lens and a near refractive power suitable for near vision in a lower portion of the progressive multifocal lens.

[0083] - Optimize the surface of the working spectacle lens of the numerical representation so as to provide at least a distance portion located in an upper section of the progressive multifocal lens, a near portion located in a lower section of the progressive multifocal lens, and an intermediate zone extending between the distance portion and the near portion, the distance portion including a distance reference point having the distance refractive power, the near portion including a near reference point having the near refractive power. The near reference point may define the apex of the near portion and demarcate this portion in the vertical direction.

[0084] - Superimpose a plurality of microlenses on the surface of the progressive multifocal lens.

[0085] - Establish an optimized numerical representation of the working spectacle lens with superimposed microlenses as the numerical representation of the progressive multifocal lens.

[0086] These instructions further cause the computer to superimpose a number of microlenses such that the microlenses are excluded from all regions of the surface that are below an imaginary line that extends from the nose to the temporal limit of the progressive multifocal lens at a vertical coordinate above the near vision reference point, where the value of the coordinate lies within the range between 1.5 mm and 3 mm. In many cases, a value between 1.8 mm and 2.2 mm is suitable, for example, a value of 2 mm.

[0087] According to a third aspect of the present invention, there is also provided a non - volatile computer - readable storage medium having program code stored thereon. The program code includes instructions for establishing a numerical representation of a progressive multifocal lens, which instructions, when executed by a computer, cause the computer to at least:

[0088] - Obtain a far - vision refractive power suitable for far vision in an upper portion of the progressive multifocal lens and a near - vision refractive power suitable for near vision in a lower portion of the progressive multifocal lens.

[0089] - Optimize the surface of the working spectacle lens of the numerical representation so as to provide at least a far - vision portion located in an upper section of the progressive multifocal lens, a near - vision portion located in a lower section of the progressive multifocal lens, and an intermediate zone extending between the far - vision portion and the near - vision portion, the far - vision portion including a far - vision reference point having a far - vision refractive power, and the near - vision portion including a near - vision reference point having a near - vision refractive power. The near - vision reference point may define the apex of the near - vision portion and demarcate this portion in the vertical direction.

[0090] - Superimpose a number of microlenses on the surface of the progressive multifocal lens.

[0091] - Establish the working spectacle lens with the superimposed microlenses of the optimized numerical representation as the numerical representation of the progressive multifocal lens.

[0092] The program code further includes instructions that cause the computer to superimpose a number of microlenses such that the microlenses are excluded from all regions of the surface that are below an imaginary line that extends from the nose to the temporal limit of the progressive multifocal lens at a vertical coordinate above the near - vision reference point, where the value of the coordinate lies within the range between 1.5 mm and 3 mm. In many cases, a value between 1.8 mm and 2.2 mm is suitable, for example, a value of 2 mm.

[0093] Furthermore, according to a third aspect of the present invention, there is also defined a data - processing system for establishing a numerical representation of a progressive multifocal lens provided with microlenses and having synchronous myopic defocus. The data - processing system includes a processor and at least one memory, wherein, by means of instructions of a computer program stored in the memory, the processor is configured to at least:

[0094] -Obtain a distance refractive power suitable for distance vision in the upper part of the progressive multifocal lens and a near refractive power suitable for near vision in the lower part of the progressive multifocal lens.

[0095] -Optimize the surface of the working eyewear lens represented numerically so as to provide at least a distance portion located in the upper section of the progressive multifocal lens, a near portion located in the lower section of the progressive multifocal lens, and an intermediate zone extending between the distance portion and the near portion, the distance portion including a distance reference point having a distance refractive power, the near portion including a near reference point having a near refractive power. The near reference point may define the apex of the near portion and delimit this portion in the vertical direction.

[0096] -Superimpose a plurality of microlenses on the surface of the progressive multifocal lens.

[0097] -Establish an optimized numerically represented working eyewear lens with superimposed microlenses as a numerical representation of the progressive multifocal lens.

[0098] By means of instructions stored in the memory, the processor is further configured to superimpose a plurality of microlenses such that the microlenses are excluded from all regions of the surface below an imaginary line that extends from the nose to the temporal limit of the progressive multifocal lens at a vertical coordinate above the near reference point, where the value of the coordinate lies within the range between 1.5 mm and 3 mm. In many cases, a value between 1.8 mm and 2.2 mm is suitable, for example, a value of 2 mm.

[0099] The data processing system of the present invention allows the execution of the computer-implemented method of the present invention and thus allows the establishment of a numerical representation of the progressive multifocal lens of the present invention, while the computer program of the present invention and the non-volatile computer-readable storage medium of the present invention allow the transformation of a computer into the data processing system of the present invention. Further developments of the data processing system, the computer program, and the non-volatile computer-readable storage medium may enable them to allow further developments of the computer-implemented method of the present invention.

[0100] Furthermore, according to a third aspect of the present invention, a computer-implemented method for establishing a numerical representation of a progressive multifocal lens provided with microlenses and having synchronous myopic defocus is defined. The computer-implemented method at least comprises the following steps:

[0101] -Obtain a distance refractive power suitable for distance vision in the upper part of the progressive multifocal lens and a near refractive power suitable for near vision in the lower part of the progressive multifocal lens;

[0102] - Optimize the surface of the working spectacle lens with a numerical representation so as to provide at least a distance vision portion located in the upper section of the progressive multifocal lens, a near vision portion located in the lower section of the progressive multifocal lens, and an intermediate zone extending between the distance vision portion and the near vision portion, the distance vision portion including a distance vision reference point having a distance vision refractive power, the near vision portion including a near vision reference point having a near vision refractive power;

[0103] - Superimpose a plurality of microlenses on the surface of the progressive multifocal lens; and

[0104] - Establish a working spectacle lens with an optimized numerical representation of superimposed microlenses as a numerical representation of the progressive multifocal lens.

[0105] The microlenses are superimposed such that the microlenses are excluded from all regions of the surface below an imaginary line that extends from the nose of the spectacle lens to the temple limit at a vertical coordinate above the near vision reference point, where the vertical coordinate is at a distance within the range between 1.5 mm and 3 mm above the near vision reference point (7). In many cases, a distance between 1.8 mm and 2.2 mm is suitable, for example, a value of 2 mm.

[0106] The computer-implemented method of the present invention allows for the establishment of a numerical representation of the progressive multifocal lens of the present invention. Further developments of the computer-implemented method may enable them to perform further developments of the computer-implemented method of the present invention.

[0107] From the following description of exemplary embodiments of the present invention in conjunction with the accompanying drawings, further features, characteristics and advantages of the present invention will become apparent.

[0108] Figure 1 A first exemplary embodiment of a progressive multifocal lens with microlenses superimposed on its surface is shown.

[0109] Figure 2 A second exemplary embodiment of a progressive multifocal lens with microlenses superimposed on its surface is shown.

[0110] Figure 3 A third exemplary embodiment of a progressive multifocal lens with microlenses superimposed on its surface is shown.

[0111] Figure 4 A fourth exemplary embodiment of a progressive multifocal lens with microlenses superimposed on its surface is shown.

[0112] Figure 5 An exemplary embodiment of a computer-implemented method for establishing a numerical representation of a progressive multifocal lens with microlenses superimposed on its surface is shown.

[0113] Figure 6Shows a part of a mold for molding a progressive multifocal lens with microlenses.

[0114] Figures 7 to 10 Shows different states in the manufacturing process for manufacturing a progressive multifocal lens with microlenses.

[0115] Now will be regarding Figures 1 to 4 Describe various exemplary embodiments of the progressive multifocal lens of the present invention, which show contour maps of the RMS blur of the power-variation surface of a progressive multifocal lens with a first add power of +1.50D, and a microlens array with a second add power of +2.50D superimposed on the corresponding power-variation surface. The innermost contour represents an RMS blur of 0.25D, and adjacent contours represent an increase in RMS blur of 0.25D. The contour maps of the exemplary embodiments each represent a progressive multifocal lens with a diameter of 40 mm.

[0116] It should be noted that the contour maps of the RMS blur are based on ray tracing of a model progressive multifocal lens with a refractive index of 1.60 for the material, the model progressive multifocal lens having a base curve of 3.10D and a spherical back surface of 6.11D, providing a lens power of -3.00D at the far vision reference point, zero prism power at the prism reference point, a center thickness of 1.5 mm; located in front of the eye, at a posterior vertex distance of 27 mm from the eye's rotation center, tilted forward 7 degrees in the actual wearing configuration. The assumed object field for the ray tracing has a vertically varying distance starting from infinity (a refractive distance of 0.00D), for all rays passing through the front surface of the lens at heights above the fitting cross (FC) with a linearly increasing refractive object distance below the FC until the near vision reference point, at which the object distance is 0.40 m (a refractive object distance of 2.50D). Additionally, for the calculation of the RMS blur, it is assumed that the wearer can accommodate up to a power error of 1.00D.

[0117] In an exemplary embodiment, the power-varying surfaces each provide a designated distance portion 1 in the upper part of the progressive multifocal lens and a designated near portion 3 in the lower part of the progressive multifocal lens. The distance portion 1 includes a distance reference point 5 which provides a distance refractive power for the wearer according to the prescription. Similarly, the near portion 3 includes a near reference point 7 which provides an add power to reduce the accommodation lag when viewing near objects. There is an intermediate zone 9 extending between the distance portion 1 and the near portion 3, in which the refractive power provided by the progressive multifocal lens gradually increases from the distance refractive power to the near refractive power. Typically, the near reference point 7 is located between 6 mm and 12 mm, particularly between 7 mm and 10 mm, below the geometric center of the spectacle lens and may be displaced in the nasal or temporal direction relative to the geometric center. In the present exemplary embodiment, the near reference point 7 is located 8 mm below the geometric center of the circular uncut progressive multifocal lens.

[0118] In an exemplary embodiment, the near refractive power is the power generated by adding the add power to the distance refractive power, and the add power is given in the prescription as well as the distance refractive power. In all exemplary embodiments, this add power is 1.50 D and the length of the intermediate zone is 12 mm. There are peripheral zones 11 on the left and right of the near portion, in which the average add power does not exceed 0.125 D. The spacing between these zones on the left and right of the near portion is 25 mm or less, particularly may be 20 mm or less. Thus, the power-varying surfaces provide a large average add power gradient in the regions adjacent to the near portion on the left and right. Such power-varying surfaces are described in WO 2018 / 100012 A1. Therefore, for further details regarding the power-varying surfaces, reference may be made to this document.

[0119] To provide synchronous myopic defocus, the microlenses 13 are superimposed on the power-varying surfaces of the progressive multifocal lens. In all exemplary embodiments, the power-varying surface is the front surface of the corresponding progressive multifocal lens. However, in principle, the power-varying surface may be the rear surface of the corresponding progressive multifocal lens instead of the front surface. In this case, the microlenses also need to be applied to the rear surface and the microlenses will need to have a less concave shape relative to the underlying concave rear surface.

[0120] In an exemplary embodiment, the microlenses 13 are superimposed on the surface with varying dioptric power in the form of a hexagonal grid of microlenses, where each microlens 13, except for those located at the edge of the array, has six nearest neighboring microlenses. The distance between the nearest neighboring microlenses measured from the geometric center of the microlens 13 is constant, and the value of this distance is in the range between 1.3 mm and 2.0 mm. Thus, the microlenses 13 are arranged in a hexagonal pattern. However, in an alternative embodiment of the present invention, the positions of the microlenses 13 can also form a rectangular pattern, particularly a quadrilateral pattern, which would mean that each microlens 13 not located at the edge of the array has only 4 nearest neighboring microlenses.

[0121] In this exemplary embodiment, each microlens 13 provides a second add power that is 1.0 D higher than the add power at the near vision reference point 7 (which can be referred to as the first add power in the context of this specification). In the exemplary embodiment, the first add power at the near vision reference point 7 is 1.50 D, and each microlens 13 provides a second add power of 2.50 D.

[0122] There is a proportion between 30% and 50% of the surface area of the microlenses 13 that can be covered by microlenses. In the case of the distance between adjacent microlenses 13 as described above, this can be achieved if elliptical microlenses are used, where the arithmetic mean of the semi-major axis and the semi-minor axis is in the range between 0.25 mm and 0.75 mm. Note that if the semi-major axis and the semi-minor axis have the same dimensions, the elliptical microlens will be a circular microlens. In the context of this specification, such a circular microlens should be considered a special case of an elliptical microlens.

[0123] Figures 1 to 4 The exemplary embodiments shown differ from each other in the areas of the corresponding progressive multifocal lenses covered by the microlenses 13 and the coverage rates provided by the corresponding microlens arrays in these areas. However, what all exemplary embodiments have in common is that the microlenses are excluded from all areas of the surface with varying dioptric power that are below an imaginary line 15 that extends from the nose to the temporal limit of the progressive multifocal lens and is located at a vertical coordinate y = 2 mm above the near vision reference point 7 (i.e., the coordinate y is at a distance of 2 mm above the near vision reference point 7). Figures 1 to 4 The contour maps shown are oriented such that the imaginary line 15 is represented by a horizontal line. Additionally, in Figure 1 and Figure 3In the exemplary embodiment shown, the microlenses 13 are present only in regions where the RMS blur of the ray tracing exceeds a threshold of 0.25 D. In the context of this specification, the RMS blur should be considered the physiological blur experienced by a wearer of a progressive multifocal lens due to the mean spherical error squared (SphErr) and the mean astigmatic error squared (AstErr) added together with appropriate weights A, B, to reflect the way the human visual system integrates such optical errors. An example of calculating the RMS blur is RMS = Sqrt(SphErr 2 +(AstErr / 2) 2 ), with weights of 1 and 1 / 2 respectively. However, in other examples, each weight may have a value taken from the range between 0 and 1.

[0124] In Figure 1 the exemplary embodiment shown, the microlens 13 array is substantially to the left and right of the intermediate zone 9. The near vision portion 3 is completely free of microlenses 13 because the near vision portion is entirely below the imaginary line 15. All microlenses 13 are elliptical, with the dimensions of their semi-major and semi-minor axes between 0.25 mm and 0.75 mm. While some microlenses 13 have a distinct elliptical shape, other microlenses have a more circular shape, especially those located at the upper end of the array. In this exemplary embodiment, the distance between the centers of adjacent microlenses 13 is 1.5 mm, which results in a coverage of approximately 42%.

[0125] Figure 2 The exemplary embodiment of the progressive multifocal lens shown is a modification of Figure 1 the exemplary embodiment shown. Figure 2 The exemplary embodiment shown differs from Figure 1 the exemplary embodiment shown in that the microlens 13 array is also present in the portion of the distance vision portion 1 where the RMS blur is below the threshold of 0.25 D. The microlens 13 array in the distance vision portion 1 forms a semi-circular ring centered on the fitting cross 17, where the inner radius of the semi-circular ring is 5 mm and the outer radius of the semi-circular ring is 17.5 mm. Additionally, the microlenses have been excluded from the measurement circle to enable simple verification of the lens power by an optical dispenser. As can be seen from Figure 2It can be seen that the microlenses 13 in the distance vision portion 1 are rounder than the microlenses 13 on the left and right sides of the intermediate zone 9. The reason is that the surface astigmatism in the distance vision portion 1 is less than that in the regions on the left and right sides of the intermediate zone 9. The higher the surface astigmatism, the greater the ellipticity of the microlens 13. The larger coverage rate of the microlenses around the fitting cross on the lens surface will enable the wearer to see more frequent synchronous myopic defocus and will be beneficial to correctly centering the distance vision on the fitting cross. For young Asian wearers, due to their flat noses, the slipping of the frame is often a problem, and this inhibits the correct use of the near vision area of the PAL to view near objects, because if the frame has slipped down the nose from its intended position, the near vision reference point is too low.

[0126] Figure 3 A third exemplary embodiment of the progressive multifocal lens of the present invention is shown. The difference between this exemplary embodiment and Figure 1 the exemplary embodiment shown is that the distance between the centers of adjacent microlenses 13 is 1.8 mm instead of 1.5 mm, which makes the coverage rate of the area covered by the microlenses 13 30%. In all other aspects, Figure 3 the exemplary embodiment shown and Figure 1 the exemplary embodiment shown are not different.

[0127] Figure 4 A fourth exemplary embodiment of the progressive multifocal lens of the present invention is shown. This exemplary embodiment is similar to Figure 2 the exemplary embodiment shown. The difference between this exemplary embodiment and Figure 2 the embodiment shown is that the distance between adjacent microlenses 13 is 1.8 mm instead of 1.5 mm, which makes the coverage rate of the area covered by the microlenses 13 30%. In all other aspects, Figure 4 the exemplary embodiment shown and Figure 2 the exemplary embodiment shown are not different.

[0128] Next, an exemplary embodiment of the computer-implemented method of the present invention will be described with respect to Figure 5 a flowchart that shows the steps of the method. In this exemplary embodiment, the method is executed on a computer that has been transformed into a data processing system for establishing a numerical representation of a progressive multifocal lens by means of a computer program having program code including instructions that, when executed by the computer, cause the computer to execute the computer-implemented method. Such a computer program can be loaded from a non-volatile storage medium into the memory of the computer. Then, the instructions of the computer program loaded into the memory can be executed by the processor of the computer in order to execute the method of establishing a numerical representation of a progressive multifocal lens.

[0129] In a first step after starting the method, the distance vision refractive power and the add power prescribed for the wearer are loaded into the computer. Note that the distance vision refractive power and the add power allow obtaining the near vision refractive power of the wearer. Additionally, the target design is also loaded in step S1. In the case where the wearer has astigmatism, strabismus or any other optical aberration, additional data can be loaded into the computer in step S1. For example, the values of the cylinder and the cylinder axis or the value of the prism can be loaded. However, in the description of the present exemplary embodiment, these additional aberrations are ignored as they are not necessary for understanding the described method.

[0130] Based on the distance vision reference power, the add power and the target design loaded in step S1, the front surface of the numerical representation of the working spectacle lens is optimized. Although the front surface of the working spectacle lens is optimized in the present embodiment, the rear surface of the working spectacle lens can also be optimized. This optimization is done by iteratively optimizing the parameters of the parametric piecewise defined function representing the front surface. In each step of the iteration, by means of a ray tracing process, based on the refractive index of the selected material, the current curvature of the front surface of the working spectacle lens (defined by the current set of parameters of the piecewise defined function), the curvature of the rear surface, the thickness of the working spectacle lens, and the object distance at which the light beam emerges, the current back focal length of a number of light beams passing through the working spectacle lens is calculated. The light beams represent different viewing directions of the eye through the working spectacle lens. In the calculation of the current back focal length of the light beam, the position of the progressive multifocal lens in front of the eye according to the actual wearing position is also considered. In addition to the current back focal length of the light beam, the deviation between the calculated current back focal length and the back focal length generated by the prescription is determined. Then, the difference between the calculated deviation and the deviation given by the target design is determined. These differences are weighted and aggregated in a global merit function. Optionally, the merit function can also include non-optical deviations from the target values, for example, deviations from the required surface curvature or the required thickness of the progressive multifocal lens.

[0131] After calculating the value of the merit function, it is checked whether the calculated value represents a minimum. In the case of "yes", the iteration ends and the method proceeds to step S3; in the case of "no", the next iteration step is executed.

[0132] After the optimization is completed, in step S3, a microlens array is superimposed on the power change surface of the numerical representation of the working spectacle lens. Each microlens provides a second add power which, in the present exemplary embodiment, is at least equal to or higher than the add power added to the distance vision refractive power to obtain the near vision refractive power. The microlenses are elliptical and the ellipticity is determined by the surface astigmatism of the underlying surface. The distance between the microlenses is set such that the desired coverage of the area covered by the microlenses is achieved.

[0133] After the microlens array is superimposed on the surface with varying dioptric power, in step S4, the resulting surface is output as a numerical representation of the desired progressive multifocal lens.

[0134] Based on the numerical representation of the progressive multifocal lens, the corresponding physical progressive multifocal lens can be manufactured by using a suitable manufacturing process. For example, based on the numerical representation of the progressive multifocal lens, a mold 31 can be formed, which is then used for injection molding of a thermoplastic material. In Figure 6 a part of the mold 31 for molding a progressive multifocal lens with microlenses is schematically shown. Figure 6 The part shown in is the part for forming the surface with microlenses, which, in the present exemplary embodiment, is the surface with varying dioptric power. This part provides a mold surface 33, which has an inverted shape of the surface with varying dioptric power to be produced. In this mold surface 33, there are recesses 35 having an inverted shape of the microlenses to be formed.

[0135] An alternative way of manufacturing a progressive multifocal lens as exemplified above is to provide a progressive multifocal lens without microlenses and to apply additional material on the surface of the progressive multifocal lens, particularly on the side with varying dioptric power. This additional material can be shaped to form the microlenses 13. The application and shaping can be done, for example, by microdroplet ejection (where the surface tension of the microdroplets provides the shape of the microlenses) in a single step, or in successive steps. As an exemplary embodiment of a manufacturing method for performing the application and shaping in successive steps, the thermal reflow method will be referred to Figures 7 to 10 These figures schematically show different states of the progressive multifocal lens during the manufacturing process.

[0136] At the start of the method, a progressive multifocal lens 19 without microlenses 13 is provided. This progressive multifocal lens 19 can be manufactured according to any known method for manufacturing progressive multifocal lenses. Next, an additional material layer 21 is applied on the surface of the progressive multifocal lens 19, particularly on the surface 23 with varying dioptric power (see Figure 7 ). As the additional material, a photoresist material is used. Then, a mask 25 having an elliptical structure 27 is applied on the photoresist material layer. The elliptical structure 27 covers those regions of the surface of the additional material layer 21 where the microlenses 13 are to be formed. Then, as Figure 8 shown, the masked photoresist material layer is exposed to ultraviolet light. This exposure removes the photoresist material of the additional material layer 21 where it is not covered by the elliptical structure 27 of the mask 25, leaving cylindrical islands 29 of photoresist material on the surface 23 (see Figure 9)。In the next step, the structure is heat-treated so that the photoresist material of the cylindrical island 29 becomes viscous, causing the material of the cylindrical island 29 to flow into the micro-lens 13 in a spherical shape. In Figure 10 Figure 19 shows the resulting progressive multifocal lens 19 having the micro-lenses 13.

[0137] Although the heat reflux method has been described as an exemplary embodiment of the manufacturing method (where application and shaping are done in successive steps), other methods (such as an imprinting method) are also possible.

[0138] The present invention has been described with respect to exemplary embodiments for illustrative purposes. However, those skilled in the art recognize that departures from the exemplary embodiments are possible within the scope of the present invention. For example, coverages other than 30% or 42% are possible, such as 40% or 60%, as long as the coverage is at least 30%. Additionally, the progressive multifocal lens may have an additional add power other than 1.50D. Similarly, the second add power provided by the micro-lenses may be different from the 2.50D described in the exemplary embodiment, as long as the second add power is at least as large as the add power used to obtain the near vision refractive power. Also, the vertical coordinate above the near vision reference point (at which the imaginary line extends from the nose to the temporal limit of the progressive multifocal lens) is selected to be a distance of 2 mm from the near vision reference point. However, in alternative embodiments, the distance at which the vertical coordinate is located above the near vision reference point may be any value outside the range between 1.5 mm and 3 mm. Therefore, the present invention should not be limited by the exemplary embodiments but only by the independent claims.

[0139] Reference Numerals

[0140] 1 distance vision portion

[0141] 3 near vision portion

[0142] 5 distance vision reference point

[0143] 7 near vision reference point

[0144] 9 intermediate zone

[0145] 11 zone with an average add power equal to or lower than 0.125D

[0146] 13 micro-lens

[0147] 15 imaginary line

[0148] 17 fitting cross

[0149] 19 progressive multifocal lens

[0150] 21 additional material layer

[0151] 23 diopter change surface

[0152] 25 mask

[0153] 27 elliptical structure

[0154] 29 island

[0155] 31 mold

[0156] S1 Loading

[0157] S2 Optimization

[0158] S3 Superimposing microlenses

[0159] S4 Outputting the numerical representation of the progressive multifocal lens

Claims

1. A progressive multifocal lens (19) provided with microlenses and having synchronous myopic defocus, wherein the dioptric power change surface (23) provides at least: - A designated distance portion (1) adapted for distance vision, located in the upper section of the progressive multifocal lens (19); - A designated near portion (3), located in the lower section of the progressive multifocal lens, the near portion (3) including a near reference point (7) having a near refractive dioptric power adapted for near vision; and - A designated intermediate zone (9) extending between the designated distance portion (1) and the designated near portion (3); Wherein a plurality of microlenses (13) are superimposed on the surface (23) of the progressive multifocal lens (19), Characterized in that, The microlenses (13) are excluded from all regions of the surface (23) that are below an imaginary line (15) that extends from the nose to the temporal limit of the progressive multifocal lens (19) at a vertical coordinate (y) above the near vision reference point (7), where the vertical coordinate (y) is at a distance within the range between 1.5 mm and 3 mm above the near vision reference point (7). Wherein, the progressive multifocal lens (19) is a circular uncut progressive multifocal lens.

2. The progressive multifocal lens (19) according to claim 1, characterized in that, There are peripheral zones (11) on the left and right sides of the specified near vision portion (3), where the average add power does not exceed 0.125 D, and the interval between the peripheral zones (11) on the left and right sides of the near vision portion (3) is 25 mm or less.

3. The progressive multifocal lens (19) according to claim 1 or claim 2, characterized in that, In those parts of the progressive multifocal lens where the microlenses (13) are not excluded, the microlenses (13) are present at least in the following zones of the surface (23): in these zones, the physiological blur experienced by the wearer of the progressive multifocal lens due to the sum of the mean spherical error squared (SphErr) and the mean astigmatic error squared (AstErr) with weights A, B (RMS blur) exceeds a threshold of 0.25 D.

4. The progressive multifocal lens (19) according to claim 3, characterized in that, The values of these weights A, B are respectively within the range between 1 / 2 and 1.

5. The progressive multifocal lens according to claim 1 or claim 2, characterized in that, - The distance vision portion (1) includes a distance vision reference point (5) having a distance vision refractive power; - The near vision refractive power at the near vision reference point (7) is given by adding a first add power to the distance vision refractive power; and - Each microlens (13) provides a second add power that is at least as high as the first add power.

6. The progressive multifocal lens (19) according to claim 5, characterized in that, A fitting cross (17) is provided on the progressive multifocal lens (19), and the microlenses (13) are distributed in a region on the distance vision portion (1) that forms a semi-circular ring, the smaller radius of the semi-circular ring is between 4 mm and 6 mm and the larger radius is between 17 mm and 18 mm, and there are no microlenses (13) in a region having a radius of at least 4 mm around the distance vision reference point (5).

7. The progressive multifocal lens (19) according to claim 1 or claim 2, characterized in that, The microlenses (13) superimposed on the surface (23) form a microlens array covering a region on the surface (23), and it is characterized in that the proportion of the region covered by the microlenses (13) is at least 30%.

8. The progressive multifocal lens (19) according to claim 1 or claim 2, characterized in that, The microlenses (13) superimposed on the surface (23) form a microlens array, wherein: - Each microlens (13) that is not located at the edge of the microlens array has at least four neighboring microlenses, - The distance between the centers of adjacent microlenses (13) is within the range between 1.3 mm and 2.0 mm, and - Each microlens (13) is elliptical, and the arithmetic mean of its semi-major axis and semi-minor axis is within the range between 0.25 mm and 0.75 mm.

9. The progressive multifocal lens (19) according to claim 1 or claim 2, characterized in that, The surface on which these microlenses (13) are superimposed is the power-varying surface (23).

10. A method for manufacturing a progressive multifocal lens (19) provided with microlenses (13) and having synchronous myopic defocus, the method comprising the steps of: - Provide a progressive multifocal lens (19) having a surface (23) with a varying dioptric power, wherein the surface (23) with a varying dioptric power provides at least a designated distance portion (1) adapted for distance vision in an upper section of the progressive multifocal lens (19), a designated near portion (3) in a lower section of the progressive multifocal lens (19), and a designated intermediate zone (9) extending between the designated distance portion (1) and the designated near portion (3), the near portion (3) including a near reference point (7) having a near refractive dioptric power adapted for near vision; and - Superimpose a plurality of microlenses (13) on the surface (23) of the progressive multifocal lens (19), characterized in that when superimposing these microlenses (13), the superimposition of the microlenses (13) is excluded from all regions of the surface (23) located below an imaginary line (15), the imaginary line extending from the nose of the progressive multifocal lens (19) to the temporal limit at a vertical coordinate (y) above the near reference point (7), wherein the vertical coordinate (y) is at a distance within the range between 1.5 mm and 3 mm above the near reference point (7).

11. The method according to claim 10, characterized in that, Manufacture a circular uncut progressive multifocal lens (19).

12. The method according to claim 10 or claim 11, characterized in that, Provide a progressive multifocal lens (19) having peripheral zones (11) on the left and right sides of the designated near portion (3) as the progressive multifocal lens (19), in these peripheral zones, the average add power does not exceed 0.125 D, and the spacing between these peripheral zones (11) on the left and right sides of the near portion (3) is 25 mm or less.

13. The method according to claim 10 or claim 11, characterized in that, The plurality of microlenses (13) are superimposed on the surface (23) of the progressive multifocal lens (19) such that in those portions of the progressive multifocal lens (19) where the microlenses (13) are not excluded, the microlenses (13) are present in regions where the RMS blur of the surface (23) exceeds a threshold of 0.25 D.

14. The method according to claim 10 or claim 11, characterized in that, In addition to the near portion (3), the distance portion (1) includes a distance reference point (5) providing a distance refractive dioptric power, wherein the near refractive dioptric power at the near reference point (7) is given by adding a first add power to the distance refractive dioptric power, and each superimposed microlens (13) provides a second add power at least as high as the first add power.

15. The method according to claim 14, characterized in that, Provide a fitting cross (17) on the progressive multifocal lens (19), and when these microlenses (13) are superimposed on the surface (23), the microlenses (13) are distributed in a region forming a semi - ring in the distance portion (1), the smaller radius of the semi - ring is between 4 mm and 6 mm and the larger radius is between 17 mm and 18 mm, and wherein there are no microlenses (13) in a region having a radius of at least 4 mm around the distance reference point (5).

16. The method according to claim 10 or claim 11, characterized in that, The microlenses (13) are superimposed on the surface (23) in the form of a microlens array covering a region of the surface (23), and are characterized in that the superimposition is completed such that the proportion of the region covered by the microlenses (13) is at least 30%.

17. The method according to claim 10 or claim 11, characterized in that, The plurality of microlenses (13) are superimposed on the surface (23) such that the plurality of microlenses form a microlens array, wherein: - each microlens (13) not located at the edge of the microlens array has at least four neighboring microlenses, - the distance between the centers of adjacent microlenses (13) is in the range between 1.3 mm and 2.0 mm, and - each microlens (13) is elliptical, and the arithmetic mean of its semi-major axis and semi-minor axis is in the range between 0.25 mm and 0.75 mm.

18. The method according to claim 10 or claim 11, characterized in that, These microlenses (13) are superimposed on the surface (23) with varying dioptric power.

19. The method according to claim 10 or claim 11, characterized in that, Providing the progressive multifocal lens (19) and superimposing these microlenses (13) on the surface of the progressive multifocal lens (19) are done for a numerical representation of the progressive multifocal lens, the mold (31) is manufactured based on the numerical representation of the progressive multifocal lens, and the progressive multifocal lens (19) is manufactured by molding or casting using the mold (31).

20. The method according to claim 10 or claim 11, characterized in that, Providing the progressive multifocal lens (19) and superimposing these microlenses (13) on the surface of the progressive multifocal lens are done by: - providing a progressive multifocal lens (19) without microlenses (13); - applying an additional material (21) to the surface of the progressive multifocal lens; and - shaping the additional material (21) to form these microlenses (13).

21. A computer program product for establishing a numerical representation of a progressive multifocal lens provided with microlenses and having synchronous myopic defocus, the computer program product comprising a computer program, the computer program comprising program code having instructions which, when executed by a computer, cause the computer to at least: - Obtain a distance refractive power suitable for distance vision in the upper part of the progressive multifocal lens and a near refractive power suitable for near vision in the lower part of the progressive multifocal lens; - Optimize the surface of the numerically represented work eyewear lens to provide at least a distance vision part (1) located in the upper section of the progressive multifocal lens (19), a near vision part (3) located in the lower section of the progressive multifocal lens, and an intermediate zone (9) extending between the distance vision part (1) and the near vision part (3), the distance vision part (1) including a distance reference point (5) having the distance refractive power, and the near vision part (3) including a near reference point (7) having the near refractive power; - Superimpose a plurality of microlenses (13) on the surface of the progressive multifocal lens; and - Establish the numerically represented work eyewear lens with the superimposed microlenses (13) as the numerical representation of the progressive multifocal lens; It is characterized in that These instructions cause the computer to superimpose the plurality of microlenses (13) such that the microlenses (13) are excluded from all regions of the surface located below an imaginary line (15) that extends from the nose to the temporal limit of the spectacle lens at a vertical coordinate (y) above the near vision reference point (7), where the vertical coordinate (y) is at a distance in the range between 1.5 mm and 3 mm above the near vision reference point (7).

22. The computer program product according to claim 21, characterized in that Establish a numerical representation of a circular uncut progressive multifocal lens (19).

23. A non-volatile computer-readable storage medium storing program code, the program code including instructions for establishing a numerical representation of a progressive multifocal lens provided with microlenses and having synchronous myopic defocus, which when executed by a computer cause the computer to at least: - Obtain a distance refractive power suitable for distance vision in the upper part of the progressive multifocal lens and a near refractive power suitable for near vision in the lower part of the progressive multifocal lens, - Optimize the surface of the numerically represented work eyewear lens to provide at least a distance vision part (1) located in the upper section of the progressive multifocal lens (19), a near vision part (3) located in the lower section of the progressive multifocal lens, and an intermediate zone (9) extending between the distance vision part (1) and the near vision part (3), the distance vision part (1) including a distance reference point (5) having the distance refractive power, and the near vision part (3) including a near reference point (7) having the near refractive power; - Superimpose a plurality of microlenses (13) on the surface of the progressive multifocal lens; and - Establish the numerically represented work eyewear lens with the superimposed microlenses (13) as the numerical representation of the progressive multifocal lens; It is characterized in that The program code includes instructions that cause the computer to superimpose the plurality of microlenses (13) such that the microlenses (13) are excluded from all regions of the surface located below an imaginary line (15) that extends from the nose to the temporal limit of the spectacle lens at a vertical coordinate (y) above the near vision reference point (7), where the vertical coordinate (y) is at a distance in the range between 1.5 mm and 3 mm above the near vision reference point (7).

24. The non-volatile computer-readable storage medium according to claim 23, characterized in that The program code stored thereon includes instructions for establishing a numerical representation of a circular uncut progressive multifocal lens (19).

25. A data processing system for establishing a numerical representation of a progressive multifocal lens, the data processing system comprising a processor and at least one memory, wherein, By means of the instructions of a computer program stored in the memory, the processor is configured to at least: - obtain a far vision refractive power suitable for far vision in the upper part of the progressive multifocal lens and a near vision refractive power suitable for near vision in the lower part of the progressive multifocal lens; - Optimize the surface of the working glasses lens with a numerical representation so as to provide at least a distance vision portion (1) located in the upper section of the progressive multifocal lens (19), a near vision portion (3) located in the lower section of the progressive multifocal lens, and an intermediate zone (9) extending between the distance vision portion (1) and the near vision portion (3), the distance vision portion (1) including a distance vision reference point (5) having the distance vision refractive power, the near vision portion (3) including a near vision reference point (7) having the near vision refractive power; - Superimpose a plurality of microlenses (13) on the surface of the progressive multifocal lens; and - Establish a working glasses lens with an optimized numerical representation having superimposed microlenses (13) as the numerical representation of the progressive multifocal lens; It is characterized in that, by means of these instructions stored in the memory, the processor is configured to superimpose the plurality of microlenses (13) such that the microlenses (13) are excluded from all regions of the surface located below an imaginary line (15) that extends from the nose of the spectacle lens to the temporal limit at a vertical coordinate (y) above the near vision reference point (7), wherein the vertical coordinate (y) is at a distance within the range between 1.5 mm and 3 mm above the near vision reference point (7).

26. The data processing system according to claim 25, wherein, By means of the instructions of a computer program stored in the memory, the processor is configured to establish a numerical representation of a circular uncut progressive multifocal lens (19).

27. A computer-implemented method for establishing a numerical representation of a progressive multifocal lens provided with microlenses and having synchronous myopic defocus, the computer-implemented method comprising at least the following steps: - Obtain a distance vision refractive power suitable for distance vision in the upper part of the progressive multifocal lens and a near vision refractive power suitable for near vision in the lower part of the progressive multifocal lens; - Optimize the surface of the working glasses lens with a numerical representation so as to provide at least a distance vision portion (1) located in the upper section of the progressive multifocal lens (19), a near vision portion (3) located in the lower section of the progressive multifocal lens, and an intermediate zone (9) extending between the distance vision portion (1) and the near vision portion (3), the distance vision portion (1) including a distance vision reference point (5) having the distance vision refractive power, the near vision portion (3) including a near vision reference point (7) having the near vision refractive power; - Superimpose a plurality of microlenses (13) on the surface of the progressive multifocal lens; and - Establish a working glasses lens with an optimized numerical representation having superimposed microlenses (13) as the numerical representation of the progressive multifocal lens; It is characterized in that the microlenses (13) are superimposed such that the microlenses (13) are excluded from all regions of the surface located below an imaginary line (15) that extends from the nose of the spectacle lens to the temporal limit at a vertical coordinate (y) above the near vision reference point (7), wherein the vertical coordinate (y) is at a distance within the range between 1.5 mm and 3 mm above the near vision reference point (7).

28. The computer-implemented method according to claim 27, wherein, Establish a numerical representation of a circular uncut progressive multifocal lens (19).

29. A progressive multifocal lens (19) provided with microlenses and having synchronous myopic defocus, wherein the dioptric power change surface (23) provides at least: - A designated distance vision portion (1) adapted for distance vision, located in the upper section of the progressive multifocal lens (19); - A designated near vision portion (3), located in the lower section of the progressive multifocal lens, the near vision portion (3) including a near vision reference point (7) having a near vision refractive dioptric power suitable for near vision; and - A designated intermediate zone (9) extending between the designated distance vision portion (1) and the designated near vision portion (3); wherein a plurality of microlenses (13) are superimposed on the surface (23) of the progressive multifocal lens (19), characterized in that, The microlenses (13) are excluded from all regions of the surface (23) that are below an imaginary line (15) that extends from the nose to the temporal limit of the progressive multifocal lens (19) at a vertical coordinate (y) above the near vision reference point (7), where the vertical coordinate (y) is at a distance within the range between 1.5 mm and 3 mm above the near vision reference point (7). Wherein, in those portions of the progressive multifocal lens where the microlenses (13) are not excluded, the microlenses (13) are present at least in the following regions of the surface (23): in these regions, the physiological blur felt by the wearer of the progressive multifocal lens due to the mean spherical error squared (SphErr) and the mean astigmatic error squared (AstErr) added together with weights A, B (RMS blur) exceeds a threshold of 0.25 D. Wherein, the values of these weights A, B are respectively within the range between 1 / 2 and 1.

30. The progressive multifocal lens (19) according to claim 29, wherein, There are peripheral zones (11) to the left and right of the specified near vision portion (3), where the mean addition power does not exceed 0.125 D, and wherein the interval between the peripheral zones (11) to the left and right of the near vision portion (3) is 25 mm or less.

31. The progressive multifocal lens according to claim 29 or claim 30, wherein, - The distance vision portion (1) includes a distance vision reference point (5) having a distance vision refractive power. - The near vision refractive power at the near vision reference point (7) is given by adding a first addition power to the distance vision refractive power; and - Each microlens (13) provides a second addition power that is at least as high as the first addition power.

32. The progressive multifocal lens (19) according to claim 31, wherein, A fitting cross (17) is provided on the progressive multifocal lens (19), and the microlenses (13) are distributed in a region on the distance vision portion (1) that forms a semi - ring, the smaller radius of the semi - ring being between 4 mm and 6 mm and the larger radius being between 17 mm and 18 mm, and wherein, there are no microlenses (13) in a region having a radius of at least 4 mm around the distance vision reference point (5).

33. The progressive multifocal lens (19) according to claim 29 or claim 30, wherein, The microlenses (13) superimposed on the surface (23) form a microlens array covering a region on the surface (23), and it is characterized in that the proportion of the region covered by the microlenses (13) is at least 30%.

34. The progressive multifocal lens (19) according to claim 29 or claim 30, wherein, The microlenses (13) superimposed on the surface (23) form a microlens array, wherein: - Each microlens (13) that is not located at the edge of the microlens array has at least four neighboring microlenses, - The distance between the centers of adjacent microlenses (13) is within the range between 1.3 mm and 2.0 mm, and - Each microlens (13) is elliptical, and the arithmetic mean of its semi - major axis and semi - minor axis is within the range between 0.25 mm and 0.75 mm.

35. The progressive multifocal lens (19) according to claim 29 or claim 30, wherein, The surface on which these microlenses (13) are superimposed is the power - varying surface (23).

Images