Spectacle lens and method for producing a spectacle lens

Abstract

The invention relates to a spectacle lens (110) for at least one eye (112) of a user (114), a method for producing a spectacle lens (110) and a computer program product comprising executable instructions for performing the method for producing a spectacle lens (110). The spectacle lens (110) comprises at least one permanent marking (120), wherein the at least one permanent marking (120) is or comprises at least one diffractive structure (124), wherein at least one diffractive pattern generated by illuminating the diffractive structure (124) is designated to be invisible under a first illumination (132) and to be visible only under a second illumination (144). The permanent mark (120) on the spectacle lens (110) is not visible to the user (114) or to a bystander who does not use a specially selected optical aid to look at the user (114) wearing the at least one spectacle lens (110), but on the other hand enables the optician or a specifically designated optical sensor to continue to control the position of the at least one spectacle lens (110) in front of at least one eye (112) of the user (114).

Description

Technical Field

[0001] The invention relates to a spectacle lens for at least one eye of a user, a method for producing a spectacle lens and a computer program product comprising executable instructions for performing the method for producing a spectacle lens. Background Art

[0002] Spectacle lenses for at least one eye of a user and methods for producing spectacle lenses are known. In general, the term "spectacle lens" refers to an optical lens typically used to correct at least one ocular aberration of at least one eye of a user. As commonly used, the term "ocular aberration" refers to the difference between the surface of an ideal optical wavefront determined for at least one eye of a user and the surface of an actual optical wavefront. In this document, the term "optical wavefront" refers to a surface that is perpendicular to the light rays along which the light propagates. In a typical human population, ocular aberrations typically include at least one second-order sphero-cylindrical focusing error, also known as "refractive error", however, at least one higher-order aberration may also be present.

[0003] However, in order to achieve an adequate correction of the at least one refractive error, it is necessary to accurately position the at least one spectacle lens in front of at least one eye of the user. This applies to at least one single vision lens, but in particular to at least one progressive power lens, the user's acceptance of which crucially depends on its accurate positioning in front of at least one eye of the user. For this purpose, opticians typically use specially adapted centering devices, which are configured for determining the exact position of the at least one spectacle lens in a spectacle frame, which is designated for receiving the at least one spectacle lens.

[0004] Until the user finally wears the glasses comprising at least one single vision lens or at least one progressive power lens, various processing steps are performed, which may however be prone to errors. As a result, although the at least one single vision lens or at least one progressive power lens may have been correctly designed to accurately correct the refractive error of at least one eye of the user, inaccurate positioning in front of at least one eye of the user may still result in suboptimal vision of the user when wearing the glasses. In this context, error-prone processing steps may in particular include grinding at least one glasses lens and adjusting the glasses frame to the user's head.

[0005] In order to be able to control the position of at least one spectacle lens, in particular at least one single vision lens or at least one progressive power lens, in front of at least one eye of a user, at least one spectacle lens usually comprises removable lens markings, which are designed to enable the optician to continue to control the position of the at least one spectacle lens in front of the at least one eye before issuing the spectacles to the user. Subsequently, the optician usually removes the lens markings before the user leaves the business premises wearing the spectacles comprising at least one single vision lens or at least one progressive power lens. However, in the case where the user may return to the optician's business premises due to rejection of the suboptimal vision caused by wearing the new spectacles, in particular due to the previous removal of the lens markings (which is particularly beneficial to the user's vision and the aesthetic appearance of the spectacles), it is no longer possible to control the positioning of the spectacles in front of at least one eye of the user. In this case, for example, the optician can no longer detect whether the user is wearing the spectacles inaccurately because the spectacle frame may be deformed.

[0006] Lens Marking Guidelines, Version 2.0, June 2014, prepared by the Lens Marking Task Force, Lens Division, Vision Commission, 225 Reinekers Lane Suite 700, Alexandria, Virginia 22314. thevisioncouncil.org , (retrieved on May 11, 2020) discloses recommendations for temporary lens markings and permanent lens markings, wherein removable marks on spectacle lenses are typically non-permanent ink marks and are removed by the optician before wearing, these removable marks are usually used to position the spectacle lenses during layout blocking and verify the power and position of the spectacle lenses during inspection and fitting, while non-removable marks on spectacle lenses are typically engraved marks and are located on an unusable area of ​​the lens blank or are only minimally visible to the observer, these non-removable marks are usually used to identify the brand and add power (if applicable) of the spectacle lenses and provide reference points for re-application of temporary marks. In particular, permanent marks that may impair the visual function of the lens should not appear within a 30mm exclusion zone around the prism reference point (PRP).

[0007] DE 102009004377 A1 discloses the introduction of a permanent structure into a spectacle lens produced by 3D printing. For this purpose, a partial volume of the spectacle lens configured to carry the permanent structure comprises a dissolvable material. As an alternative, the partial volume comprises a material having a different refractive index than the remaining material of the spectacle lens.

[0008] WO 2015 / 177370 A1 discloses a spectacle lens for a user, the spectacle lens comprising a lens body which is at least partially transparent to incident light and has a phase object which directs light incident at an incident angle on a side facing away from the user into a direction depending on the wavelength of the light and the incident angle. The phase object has a plurality of diffraction structures which diffract monochromatic light having a wavelength of 380 nm to 800 nm into the same order of diffraction with a diffraction efficiency of at least 70% when the monochromatic light is incident at an incident angle on the side of the lens facing away from the user, the incident angle being within a specific angular interval of the diffraction structure which is 15° wide and depends on the wavelength of the light.

[0009] Further holographic progressive power lenses are disclosed in the following documents: Jannik M. Trapp, Manuel Decker, Petschulat, Thomas Pertsch, Toufic G. Jabbour, Holographic progressive lenses, Proceedings of SPIE 10745, Current Developments in Lens Design and Optical Engineering XIX, 107450G (2018); Jannik M. Trapp, Manuel Decker, Petschulat, Thomas Pertsch, Toufic G. Jabbour, Design of a 2diopter holographic progressive lens, Optics Express, 26(25), 2018, 32866; and Jannik M. Trapp, Toufic G. Jabbour, Gerhard Kelch, Thomas Pertsch, and Manuel Decker, Hybrid refractive holographic single vision spectacle lenses, Journal of the European Optical Society - Rapid Publications (2019) 15:14.

[0010] US2017 / 261765 A1 discloses storing information in an optical element, which is in the form of a glass or plastic body implemented as a spectacle lens, a spectacle lens blank or a spectacle lens semi-finished product. By creating at least one mark with a marking system, information in the form of data is stored on or in the glass or plastic body. The mark can be read by a reading device. The marking system has an interface for reading information that personalizes the optical element. The mark is permanently created by the marking system on or in the optical element, at a definition point of a local body-specific coordinate system set by two points on or in the optical element. In this body coordinate system, the manufacturer specifies the position of the lens horizontal line and / or the distance reference point and / or the near reference point and / or the prism reference point.

[0011] US2019 / 231517 A1 discloses a lens comprising a back surface, a front surface, and at least one identification mark on the lens. The at least one identification mark exhibits a first visibility under ambient lighting conditions and exhibits a second visibility greater than the first visibility under lighting conditions different from the ambient lighting conditions.

[0012] US2009 / 302122 A1 discloses a method for recording data on an optical lens, the method comprising recording a source image containing data, generating a hologram of the image source, and recording the hologram on a 0.5 mm 2 Up to 15mm 2 The lens is formed on a portion of the lens surface within a range. The data can be read out by irradiating the lens with a light beam in the hologram area. A read-out image, which reproduces the source image and on which the data is readable, is formed at a certain distance from the lens. The lens can be implemented in particular in the form of an ophthalmic lens.

[0013] US2015 / 029459 A1 discloses an ophthalmic lens including clearly identifiable, highly visible embedded labels that are not visible to the wearer or others when the ophthalmic lens is set on the eye, which can be used to allow an individual to easily distinguish between a normal state of the lens and an inverted state of the lens and for any number of functions including use as a brand label, prescription label, or cosmetic enhancement. The embedded label includes a holographic record that appears only in transmitted light.

[0014] Problem to be solved

[0015] In particular with regard to the disclosure of the lens marking guide (see above), the object of the present invention is therefore to provide a spectacle lens for at least one eye of a user, a method for producing a spectacle lens and a computer program product comprising executable instructions for performing the method for producing a spectacle lens, which at least partially overcome the above-mentioned problems of the prior art.

[0016] A particular object of the invention is to introduce permanent markings on spectacle lenses which may not be visible to the user or to an observer who does not use specially selected optical aids to look at the user wearing at least one spectacle lens.

[0017] More particularly, it is desirable that the permanent marking on a spectacle lens, a single vision lens or in particular a progressive power lens is designed to enable an optician and / or a specifically designated optical sensor to continue to control the position of the at least one spectacle lens in front of at least one eye of the user. Summary of the invention

[0018] This problem is solved by a spectacle lens for at least one eye of a user, a method for producing a spectacle lens and a computer program product comprising executable instructions for carrying out the method for producing a spectacle lens, which have the features of the independent claims. Preferred embodiments are listed in the dependent claims, which can be implemented in isolation or in any combination.

[0019] As used hereinafter, the terms "having", "including" or "comprising" or any grammatical variations thereof are used in a non-exclusive manner. Therefore, these terms can refer to the situation where no other features are present in the entity described in the present context in addition to the features introduced by these terms, or the situation where one or more other features are present. As an example, the expressions "A has B", "A includes B" and "A contains B" can all refer to the situation where no other elements are present in A except B (i.e., the situation where A consists only of B), or the situation where one or more other elements are present in entity A in addition to B, such as element C, element C and element D, or even other elements.

[0020] Further, as used hereinafter, the terms "preferably", "more preferably", "particularly", "more particularly" or similar terms are used in conjunction with optional features without limiting the possibility of substitution. Therefore, the features introduced by these terms are optional features and are not intended to limit the scope of the claims in any way. As the skilled person will recognize, the present invention can be implemented by using alternative features. Similarly, features introduced by "in an embodiment of the present invention" or similar expressions are intended to be optional features without any limitation on alternative embodiments of the present invention, without any limitation on the scope of the present invention, and without any limitation on the possibility of combining the features introduced in this manner with other features of the present invention.

[0021] In a first aspect, the invention relates to a spectacle lens for at least one eye of a user.Besides the term "user", different terms may also be applied, like "subject", "person", "test person" or "spectacle wearer".

[0022] According to the invention, a spectacle lens for at least one eye of a user has a lens body which comprises at least one permanent marking, wherein the at least one permanent marking is or comprises at least one diffractive structure.

[0023] Based on section 3.5.2 of the standard ISO 13666:2019 (also referred to herein as the "standard"), the term "spectacle lens" refers to an optical lens for determining and / or correcting at least one ocular aberration of at least one eye of a user, wherein the spectacle lens is carried in front of the user's eye. Further, based on section 3.7.8 of the standard, the terms "progressive power lens", "progressive multifocal lens" and "varifocal lens" refer to a specific type of spectacle lens, which is a power-changing lens with two optical power reference points, and which is generally designed to provide correction of presbyopia and clear vision from far to near. In particular, the progressive power lens has a primary reference point also referred to as the "distant reference point" and a secondary reference point referred to as the "near reference point". Further, the term "spectacle (spectacle or eye glass)" refers to any element comprising two separate spectacle lenses and a spectacle frame, wherein each spectacle lens is ready to be received by a spectacle frame selected by the user.

[0024] As further noted above, the term "eye aberration" refers to the difference between the surface of an ideal optical wavefront determined for at least one eye of a user and the surface of an actual optical wavefront. Herein, the term "optical wavefront" refers to a surface perpendicular to the light along which the light propagates. In particular, within a typical human population, eye aberrations typically include at least one second-order sphero-cylindrical focusing error, also known as "refractive error". Various approaches can be used to describe sphero-cylindrical lenses designed to correct sphero-cylindrical focusing errors. As defined in Section 3.6.6 of the standard, the term "sphero-cylindrical lens" refers to a spectacle lens having a spherical surface and a cylindrical surface. Further, according to Section 3.13.1, a sphero-cylindrical lens is defined as a spectacle lens that combines parallel paraxial beams on two separate mutually perpendicular focal lines, whereby the spectacle lens has vertex refractive power only in two meridian planes. Further, according to Section 3.10.7, the term "vertex refractive power" is defined as the reciprocal value of the width of the paraxial section. As further defined in Sections 3.2.12 and 3.13.2, the term "meridian plane" refers to one of the two perpendicular planes of a spectacle lens having an astigmatic effect parallel to the two focal lines. In the present context, the term "astigmatic effect" corresponds to the "astigmatic difference", which is defined in Section 3.13.6 as the difference between the vertex refractive power value in the second meridian plane and the vertex refractive power value in the first meridian plane. Further, according to Section 3.13.7, "cylindrical power" refers to the algebraic difference between the refractive values ​​of these meridian planes, wherein the refractive value of a particular meridian plane used as a reference is subtracted from the refractive value of another meridian plane, and according to Section 3.13.8, "cylindrical axis" refers to the direction of a meridian plane of a spectacle lens whose vertex refractive power is used as a reference.

[0025] As an alternative, L.N. Hibos, W. Wheeler, and D. Horner (1997), Power Vectors: An Application of Fourier Analysis to the Description and Statistical Analysis of Refractive Error, Optometry and Vision Science, 74(6), S. 367-375, proposed describing spherocylindrical lenses in terms of Fourier analysis of the power distribution. They pointed out that the familiar sine-square law naturally leads to a Fourier series representation with exactly three Fourier coefficients, which represent the natural parameters of thin lenses. In this paper, the constant term corresponds to the mean spherical equivalent (MSE) power, while the amplitude and phase of the harmonics correspond to the power and axis position of the Jackson cross-cylinder (JCC) lens, respectively. Expressing the Fourier series in rectangular form allows any spherocylindrical lens to be represented as the sum of a spherical lens and two crossed cylinders (one at 0° axis and the other at 45° axis). The power of these three component lenses can be interpreted as the (x, y, z) coordinates of a vector representation of the power distribution. The power vector representation of a spherocylindrical lens can be used for numerical and graphical analysis of optometric data to solve problems involving lens combinations, comparisons of different lenses, and the statistical distribution of refractive errors.

[0026] As described above, the spectacle lens for at least one eye of a user has a lens body. As commonly used, the term "lens body" refers to a three-dimensional object that includes a spectacle lens. For a spectacle lens designated to receive incident light, modify the optical path of the incident light, and emit the modified incident light to at least one eye of a user, the lens body can be transparent or at least partially transparent to the incident light. As commonly used, "transparency" refers to a property of the lens body that is related to the ability to transmit a portion of the incident light through the lens body, wherein, depending on the desired attenuation of the incident light by the lens body, the portion can be 100% (transparent) or less but greater than 0% (partially transparent). For this purpose, the lens body includes at least one transparent or translucent material, in particular selected from glass, quartz or a suitable solid organic substance.

[0027] Further, the lens body comprises at least one permanent mark. As commonly used, the term "permanent mark" refers to a mark introduced into the lens body, which cannot be removed without applying considerable forces that would damage the spectacle lens. Therefore, the term "permanent mark" should be contrasted in particular with temporary marks, which typically comprise non-permanent inks and can therefore be easily removed by an optician before wearing by applying a gentle force that is not sufficient to damage the spectacle lens. In particular, the permanent mark comprising at least one diffraction pattern as described in more detail below can be a volume element, which is included by the lens body but occupies a maximum of 2%, preferably 1%, more preferably 0.5% of the volume of the lens body. Due to the transparency or partial transparency of the lens body, the permanent mark can in principle be placed anywhere within the lens body, or at or below the surface of the lens body.

[0028] Further, the at least one permanent mark may preferably be configured to provide information, such as at least one of a position on the lens body, an information item related to the spectacle lens or an information item related to at least one eye of the user. In particular, the at least one permanent mark is configured to provide information about at least one of the positions on the lens body. As commonly used, the term "position" refers to a two-dimensional position on the surface of the lens body or a three-dimensional position within the lens body. In particular, for an optician and / or a specifically designated optical sensor to be able to control the position of at least one spectacle lens in front of at least one eye of the user, the information about at least one position on the lens body may preferably be selected from at least one of the following:

[0029] - Distant Reference Point (DRP);

[0030] - at least one near reference point (NRP);

[0031] - Fitting Cross (FC);

[0032] - Prism Reference Point (PRP);

[0033] - Alignment reference marks.

[0034] However, other kinds of locations are feasible where relevant information can be provided by at least one permanent marking comprised by the lens body.

[0035] As mentioned above, the "distance reference point" is a primary reference point included in a progressive power lens, while the "near reference point" is a secondary reference point included in a progressive power lens. Further, the "fitting cross" (FC) refers to a position on a spectacle lens that is used as a reference point for positioning the lens in front of the user's eye, which reference point coincides with the "layout reference point" (LRP) of the progressive power lens. Further, the "prism reference point" (PRP) refers to a position on a spectacle lens at which the prism value of the finished spectacle lens is to be measured, wherein the prism reference point is located on the progressive power lens at the midpoint between the "alignment reference mark" along a horizontal axis that intersects the two marks, and the two marks are separated by a distance of 34 mm.

[0036] Alternatively or additionally, the at least one permanent marking may comprise information about an information item related to the spectacle lens, which information item may preferably be selected from at least one of the following:

[0037] - the focal power of eyeglass lenses;

[0038] - Type of eyeglass lenses;

[0039] - an identifier of the spectacle lens, in particular at least one selected from a unique identifier (UID), a unique device identifier (UDI) with UDI-DI (device identifier) ​​or UDI-PI (production identifier) ​​or a proprietary identifier;

[0040] - manufacturers of eyeglass lenses;

[0041] - Suppliers of eyeglass lenses;

[0042] - a trade name relating to spectacle lenses; or

[0043] - Trademarks related to eyeglass lenses.

[0044] However, the at least one permanent marking may comprise further items of information relating to the spectacle lens.

[0045] As mentioned above, the term "power" refers to the strength of correction of at least one eye aberration of a spectacle lens, such as the vertex refractive power. Further, the term "type" refers to at least one specification related to at least one of the material, production method or treatment of the spectacle lens. Further, the terms "manufacturer" and "supplier" indicate commercial characteristics related to the production and distribution of the spectacle lens, while the terms "trade name" and "trademark" indicate further trade-related characteristics of the spectacle lens.

[0046] Alternatively or additionally, the at least one permanent mark may include information about an information item related to at least one eye of the user, which information item may preferably be selected from at least one of the following:

[0047] - ocular aberrations, in particular at least one refractive error;

[0048] - viewing direction;

[0049] - corneal vertex distance; or

[0050] -Pupillary distance.

[0051] However, the at least one permanent marking may comprise further items of information relating to at least one eye of the user.

[0052] In particular, according to the invention, the at least one permanent mark is or comprises at least one diffractive structure. As commonly used, the term "diffractive structure" refers to a two-dimensional structure on the surface of the lens body or a three-dimensional structure in the lens body, wherein the structure is configured to generate a diffraction pattern as long as an incident light beam is incident on the diffractive structure under at least one specified condition. Therefore, as further commonly used, the term "diffraction pattern" refers to an optically visible phenomenon, which is generated by modifying the optical wavefront in a way that the spectral distribution of light in the optical wavefront changes when it comes into contact with the diffractive structure under at least one specified condition. As a result, a bystander who can look at the diffractive structure without using a specially selected optical aid under at least one specified condition can see a part of the modified optical wavefront showing the changed spectral distribution. As an alternative or in addition, a specifically designated optical sensor can be used for this purpose. As commonly used, the term "optical sensor" refers to a type of sensor configured to receive optical information and transform it into at least one electrical signal, electronic signal, optical signal or magnetic signal, which signal can be evaluated for at least one further purpose. In particular, the optical sensor can be specifically designated to be able to perceive at least one diffraction pattern.

[0053] In other words, an incident light beam incident on the lens body outside the at least one diffraction pattern or not incident on the at least one diffraction pattern under the at least one specified condition is transmitted in a manner that does not change the spectral distribution of the light beam, whereas an incident light beam incident on the at least one diffraction pattern under the at least one specified condition changes the spectral distribution of the light beam. As a result, a user of the at least one spectacle lens or an observer (such as an optician) who does not use a specifically selected optical aid to look at the user wearing the at least one spectacle lens may be able to perceive, in addition to the familiar effect of the refractive effect of the spectacle lens, no change in the incident light beam or a characteristic change in the incident light beam, wherein the latter may be used to provide desired information about at least one location on the lens body and / or at least one information item related to the spectacle lens, as described in more detail elsewhere herein.

[0054] Further, in order to arrange that the permanent marking can be visible only under the at least one specified condition, the at least one diffraction pattern can preferably be specified to be invisible under a first illumination of the spectacle lens and visible only under a second illumination of the spectacle lens. As used herein, the term "illumination" refers to electromagnetic radiation as defined in more detail below, which is configured to be incident on at least one permanent marking comprised by the lens body of the spectacle lens. As further used herein, the terms "first" and "second" are considered to be descriptive without specifying an order and without excluding the possibility that other elements of the same kind may be present. As further used herein, the term "visible" refers to the property that the at least one diffraction pattern is perceived by at least one eye of a person. Similarly, the term "invisible" refers to the property that the at least one diffraction pattern is not perceived by at least one eye of a person, which is due to at least one of the following reasons: the intensity is below the visibility threshold of at least one eye of the user, or the modified light beam generated by the diffraction structure propagates in a direction outside the field of view of at least one eye of the user. For example, although a portion of the incident light that passes through the diffractive structure may still propagate on the same optical path in an unchanged manner, this portion of light may be invisible to at least one eye of the user due to the unchanged propagation direction of the light beam.

[0055] As a result, the at least one permanent marking may remain invisible to the user wearing the at least one spectacle lens or to a bystander who does not use a specifically selected optical aid to look at the user wearing the at least one spectacle lens, but may become visible to a bystander, such as an optician, or to a specifically designated optical sensor, if the at least one specified condition can be met, thus enabling continued control of the position of the at least one spectacle lens in front of at least one eye of the user and / or retrieval of at least one information item related to the spectacle lens. As used herein, the term "specified condition" refers to at least one prerequisite to be met in order to generate visibility of the at least one diffraction pattern, in particular including at least one wavelength and / or at least one direction of illumination of the diffraction structure provided by the second illumination. As an alternative, the at least one permanent marking may become visible only when viewed through at least one additional optical element, such as a filter. In other words, the eye of the bystander, such as an optician, or the specifically designated optical sensor may only be able to perceive the diffraction structure as long as the at least one additional optical element, such as a filter, can be inserted into the optical path between the lens body of the spectacle lens and at least one eye of the bystander, or the specifically designated optical sensor, respectively.

[0056] In a preferred embodiment, the first illumination of the spectacle lens can be provided by a large bandwidth light source, and the second illumination of the spectacle lens can be provided by a small bandwidth light source. As commonly used, the term "light source" refers to any object designated to generate light. As used herein, the term "light" refers to electromagnetic radiation of at least one of the visible spectral region, the near infrared spectral region, or the near ultraviolet spectral region. As commonly used, the term "visible spectral region" refers to electromagnetic radiation with a wavelength of 380nm to 780nm, while the term "near infrared spectral region" refers to electromagnetic radiation with a wavelength of more than 780nm to 1.5μm, and the term "near ultraviolet spectral region" refers to electromagnetic radiation with a wavelength of less than 200nm to 380nm. Further, the term "bandwidth" refers to a wavelength range that can be provided by a light source. Therefore, the term "small bandwidth" refers to a wavelength range of up to 150nm, preferably up to 100nm, more preferably up to 50nm, and the term "large bandwidth" refers to a wavelength range of more than 150nm, preferably at least 200nm, more preferably at least 400nm.

[0057] Herein, a large bandwidth light source may be selected from a natural light source or an artificial light source typically used for general lighting purposes. As commonly used, the term "natural light source" refers to a light source that is available without human influence, and may include in particular sunlight (whether bright or obscured by clouds) or moonlight. Further, a large bandwidth artificial light source may be selected in particular from a white light emitting diode, an energy-saving lamp, an incandescent lamp or a gas discharge lamp, as long as such a light source has a large bandwidth and can be generally used for general lighting purposes. As commonly used, the term "white light emitting diode" refers to a combination of at least two light emitting diodes designated to generate a large bandwidth. In contrast, a small bandwidth light source may be selected from a small bandwidth artificial light source (in particular a laser light source) or a single light emitting diode.

[0058] In a specific embodiment, the diffraction structure can be specified to generate a diffraction pattern that can satisfy the at least one specified condition under illumination in at least one of the near infrared spectral region and the near ultraviolet spectral region, but not in the visible spectral region. In this specific embodiment, the small bandwidth light source can be configured to generate light that includes a segment of at least one of the near infrared spectral region and the near ultraviolet spectral region, which is diffracted by the diffraction pattern in a manner that generates light in the visible spectral region.

[0059] In general, the at least one diffractive structure may be designed to generate an arbitrary diffraction pattern which may be capable of being used for at least one purpose of the at least one permanent marking as described above or below.

[0060] However, in a preferred embodiment, the at least one diffractive structure can exhibit a reflection efficiency of 10% to 50%, preferably 15% to 30% when incident by the second illumination. As a result, the overall reflection of the at least one diffractive structure can be reduced so as to contribute to the overall reduction of the reflection intensity of the incident light by the at least one diffractive structure.

[0061] In a further preferred embodiment, the at least one specified condition may comprise an angle at which the incident light beam may be incident on the diffractive structure. As a result, the at least one diffractive structure may thus be specified to be visible only at an angle of the second illumination to the surface of the spectacle lens of at most 45°, preferably at most 30°, more preferably at most 15°.

[0062] In a further preferred embodiment, the at least one specified condition may alternatively or additionally comprise an angle at which an exit light beam may be generated by the diffractive structure when illuminated by the incident light beam. As a result, the at least one diffractive structure may thus be specified for generating an exit light beam having an angle of at most 45°, preferably at most 30°, more preferably at most 15° relative to the surface of the spectacle lens, in which case the diffraction pattern may only be visible when using the second illumination. In this way, alternatively or additionally, the visibility of the diffraction pattern may be limited.

[0063] In a further preferred embodiment, the at least one diffractive structure can be specified to generate at least one holographic pattern under the at least one specified condition. As commonly used, the term "holographic pattern" refers to an interference pattern that can be reproduced by a three-dimensional light field that illuminates a specific generated diffraction pattern. However, other kinds of diffractive structures are also feasible.

[0064] In another aspect, the present invention relates to a method for producing a spectacle lens for at least one eye of a user as disclosed elsewhere herein. In particular, the method can be used to introduce at least one permanent mark into the lens body, wherein the at least one permanent mark can be visible only if at least one specified condition is met. The method according to the invention comprises the following steps a) and b), which are preferably performed in a given order starting with step a) and continuing with step b), wherein, depending on the selected production method, these two steps can also be performed at least partially in a simultaneous manner. Additionally, further steps disclosed or not disclosed herein can be additionally performed. The steps of the method of the invention are as follows:

[0065] a) generating a spectacle lens based on the instructions configured to compensate for at least one ocular aberration of at least one eye of a user; and

[0066] b) introducing at least one permanent marking into the lens body of the spectacle lens,

[0067] Therein, the at least one permanent mark is introduced into the lens body in such a way that the at least one permanent mark is or comprises at least one diffractive structure.

[0068] According to step a), a spectacle lens is generated based on instructions configured to compensate for at least one ocular aberration of at least one eye of a user. For this purpose, a lens blank can be provided, which can subsequently be ground so as to provide the desired compensation. Based on standard 3.8.1, the term "lens blank" refers to a lens piece, wherein at most one surface is an optical surface, so that at least one other surface is ground until the desired compensation is achieved. As an alternative, an additive technology designated for generating a lens body, such as a 3D printing technology, can be performed for this purpose.

[0069] According to step b), at least one permanent mark is introduced into the lens body of the spectacle lens, wherein the at least one permanent mark can preferably be configured to provide information about at least one of a position on the lens body, an information item related to the spectacle lens or an information item related to at least one eye of the user. Herein, the lens body generated during step a) can undergo additional processing specified for this purpose. Alternatively, an additive technology (such as a 3D printing technology) that can be specified for generating the lens body can be used simultaneously for this purpose, in particular during the generation of the spectacle lens according to step a).

[0070] Herein, the at least one diffractive structure may be generated by embedding a photosensitive layer into a lens body and irradiating the photosensitive layer. As commonly used, the term "photosensitive layer" refers to an extended thin body having a structure designated to be modified by irradiation, thereby obtaining the desired diffractive structure.

[0071] As an alternative, the at least one diffraction pattern may be generated by treating the surface of the eyeglass lens by a surface treatment method selected from additive techniques or subtractive techniques. As commonly used, the term "additive techniques" refers to a process of depositing at least one additional substance on the lens body. As further commonly used, the term "subtractive techniques" refers to a process of removing a portion of the material comprised by the lens body.

[0072] As a further alternative, the at least one diffraction pattern may be generated by modifying the refractive index within at least one volume element of the lens body. As used herein, the term "refractive index" refers to the degree to which incident light is refracted upon entering the lens body or a portion thereof. Thus, modifying the refractive index within at least one volume element of the lens body may achieve a desired diffraction of the incident light. For modifying the refractive index, the chemical composition of at least one volume element within the lens body may be modified, for example, by ion exchange. However, other kinds of procedures are also possible.

[0073] Typically, the method according to the invention may be performed in a non-automatic manner, wherein a lens blank may be provided and subsequently ground, such as by using a grinding device, in order to provide the desired compensation for at least one ocular aberration of at least one eye of a user. However, in a preferred embodiment, the method according to the invention may be a computer-implemented method. As generally used, the term "computer-implemented method" refers to a method involving a programmable device, in particular a computer, a computer network or a readable medium carrying a computer program, whereby at least one method step, preferably all method steps, are performed by using at least one computer program. For this purpose, the computer program code may be provided on a data storage medium or a separate device, such as an optical storage medium, for example on a compact disc, directly on a computer or a data processing unit, in particular a mobile communication device, in particular a smartphone or a tablet, or via a network, such as an intranet or the Internet. Thus, the method according to the invention may be performed on a programmable unit configured for this purpose, such as by providing a specific computer program.

[0074] Therefore, in another aspect, the present invention relates to a computer program product comprising executable instructions for performing the method for producing a spectacle lens according to the present invention. For this purpose, the computer program may comprise instructions provided by means of a computer program code, which, when implemented on a computer or a data processing unit, are capable of performing any or all of the steps of the method as described elsewhere herein, and thus producing a spectacle lens for at least one eye of a user. In this context, the computer program code may be provided on a data storage medium or a separate device, such as an optical storage medium, for example on a compact disc, directly on a computer or a data processing unit (in particular a mobile communication device, in particular a smartphone or a tablet), or via a network (such as an intranet or the Internet).

[0075] For further details on the method for producing a spectacle lens and the related computer program product, reference may be made to the spectacle lens as disclosed elsewhere herein.

[0076] A spectacle lens for at least one eye of a user, in particular at least one single vision lens or at least one progressive power lens, a method for producing a spectacle lens and a related computer program product present various advantages over the prior art. In particular, the spectacle lens may therefore comprise permanent markings which may be configured to provide desired information about at least one position on the lens body and / or at least one information item related to the spectacle lens and / or at least one information item related to at least one eye of a user only if at least one specified condition is met. In particular, the permanent markings on the spectacle lens may on the one hand be invisible to the user or to a bystander who does not use a specifically selected optical aid to look at the user wearing the at least one spectacle lens, but on the other hand, the optician or a specifically designated optical sensor is able to continue to control the position of the at least one spectacle lens in front of at least one eye of the user. As a result, the optician can still control the positioning of the spectacles in front of at least one eye of the user even if the user wearing the spectacles comprising at least one single vision lens or at least one progressive power lens may have left the optician's business premises and may have returned despite suboptimal vision caused by wearing new spectacles. Therefore, the user's satisfaction with the at least one spectacle lens, especially the at least one single-vision lens or the at least one progressive-power lens, can be significantly improved, thereby helping the user to accept the at least one spectacle lens, especially the at least one single-vision lens or the at least one progressive-power lens.

[0077] In summary, the following embodiments are particularly preferred within the scope of the present invention:

[0078] Embodiment 1. A spectacle lens for at least one eye of a user, the spectacle lens having a lens body, wherein the lens body comprises at least one permanent mark, wherein the at least one permanent mark is or comprises at least one diffractive structure.

[0079] Embodiment 2. The eyeglass lens according to the preceding embodiment, wherein at least one diffraction pattern generated by illuminating the diffractive structure is designated to be invisible under a first illumination.

[0080] Embodiment 3. The spectacle lens according to the preceding embodiment, wherein the first illumination of the spectacle lens is provided by a wide bandwidth light source.

[0081] Embodiment 4. The eyeglass lens according to the preceding embodiment, wherein the wide-bandwidth light source is selected from a natural light source or an artificial light source for general lighting purposes.

[0082] Embodiment 5. The eyeglass lens according to the previous embodiment, wherein the wide-bandwidth light source is selected from a white light emitting diode, an energy-saving lamp, an incandescent lamp or a gas discharge lamp.

[0083] Embodiment 6. A spectacle lens according to any one of the preceding four embodiments, wherein the at least one diffraction pattern generated by illuminating the diffractive structure is designated to be visible only under a second illumination.

[0084] Embodiment 7. The eyeglass lens according to the preceding embodiment, wherein the visibility of the at least one diffraction pattern under the second illumination comprises a property of the at least one diffraction pattern as perceived by at least one eye of a person.

[0085] Embodiment 8. A spectacle lens according to any one of the two preceding embodiments, wherein the second illumination of the spectacle lens is provided by a small bandwidth light source.

[0086] Embodiment 9. The eyeglass lens according to the preceding embodiment, wherein the narrow bandwidth light source comprises a spectral band having a wavelength range of maximum 150 nm, preferably maximum 100 nm, more preferably maximum 50 nm.

[0087] Embodiment 10. The eyeglass lens according to the preceding embodiment, wherein the small bandwidth light source is selected from a laser light source or a single light emitting diode.

[0088] Embodiment 11. A spectacle lens according to any one of the two preceding embodiments, wherein the small bandwidth light source is configured to generate light in at least one of the following spectral regions: a near infrared spectral region and a near ultraviolet spectral region.

[0089] Embodiment 12. A spectacle lens according to any one of the preceding six embodiments, wherein, under a second illumination of the spectacle lens, the at least one diffractive structure exhibits a reflection efficiency of 10% to 50%, preferably 15% to 30%.

[0090] Embodiment 13. An eyeglass lens according to any of the preceding seven embodiments, wherein the at least one diffractive structure is designated to be visible only when the second illumination is at an angle of maximum 45°, preferably maximum 30°, more preferably maximum 15° relative to the surface of the eyeglass lens.

[0091] Embodiment 14. An eyeglass lens according to any of the first eight embodiments, wherein the at least one diffractive structure is designated to generate an exit light beam having an angle of a maximum of 45°, preferably a maximum of 30°, more preferably a maximum of 15° relative to the surface of the eyeglass lens only when the second illumination is used.

[0092] Embodiment 15. A spectacle lens according to any of the preceding nine embodiments, wherein the at least one diffractive structure is designated to be visible only when viewed through at least one additional optical element.

[0093] Embodiment 16. A spectacle lens according to any of the preceding ten embodiments, wherein the at least one diffractive structure is designated to be visible to at least one of: a bystander or a specifically designated optical sensor.

[0094] Embodiment 17. The spectacle lens according to any of the preceding eleven claims, wherein the at least one diffractive structure is designed to generate at least one holographic pattern under a second illumination of the spectacle lens.

[0095] Embodiment 18. The eyeglass lens according to any of the preceding embodiments, wherein the at least one permanent mark is a mark comprised by the lens body that can only be removed by applying a substantial force capable of damaging the eyeglass lens.

[0096] Embodiment 19. A spectacle lens according to any of the preceding embodiments, wherein the at least one permanent mark is configured to provide information about at least one of the following: a location on the lens body, an information item related to the spectacle lens, or an information item related to at least one eye of the user.

[0097] Embodiment 20. The eyeglass lens according to the preceding embodiment, wherein the position is a two-dimensional position on the surface of the lens body or a three-dimensional position within the lens body.

[0098] Embodiment 21. A spectacle lens according to any one of the first two embodiments, wherein the information about the position on the lens body is selected from at least one of the following: a distance reference point, at least one near reference point, a fitting cross, a prism reference point, an alignment reference mark.

[0099] Embodiment 22. A spectacle lens according to any one of the first three embodiments, wherein the information item related to the spectacle lens is selected from at least one of the following items: an indication of at least one of the following items: the focal length, type, manufacturer or supplier of the spectacle lens, or a trade name or trademark related to the spectacle lens.

[0100] Embodiment 23. A spectacle lens according to any one of the first four embodiments, wherein the information item related to at least one eye of the user is selected from at least one of the following: eye aberrations, in particular at least one refractive error; viewing direction; corneal vertex distance; or pupil distance.

[0101] Embodiment 24. An eyeglass lens according to any of the preceding embodiments, wherein the at least one diffractive structure is a volume element included by the lens body, and the volume element occupies a maximum of 2%, preferably 1%, and more preferably 0.5% of the volume of the lens body.

[0102] Embodiment 25. A spectacle lens according to any one of the preceding embodiments, wherein the lens body is transparent or at least partially transparent to incident light.

[0103] Embodiment 26. A spectacle lens according to any one of the preceding embodiments, wherein the spectacle lens is a single vision lens or a progressive power lens.

[0104] Embodiment 27. A method for producing a spectacle lens, the method comprising the following steps:

[0105] a) generating a spectacle lens based on the instructions configured to compensate for at least one ocular aberration of at least one eye of a user; and

[0106] b) introducing at least one permanent marking into the lens body of the spectacle lens,

[0107] Therein, the at least one permanent mark is introduced into the lens body in such a way that the at least one permanent mark is or comprises at least one diffractive structure.

[0108] Embodiment 28. A method according to any of the preceding method-related embodiments, wherein the at least one diffraction pattern is generated by embedding a photosensitive layer into the lens body and irradiating the photosensitive layer.

[0109] Embodiment 29. A method according to any of the aforementioned embodiments involving methods, wherein the at least one diffraction pattern is generated by processing the surface of the lens body by a surface processing method selected from additive technology or subtractive technology.

[0110] Embodiment 30. A method according to any of the preceding method-related embodiments, wherein the at least one diffraction pattern is generated by modifying the refractive index within at least one volume element of the lens body.

[0111] Embodiment 31. A computer program product comprising executable instructions for executing a method for producing an eyeglass lens for at least one eye of a user, wherein the method comprises the steps of the method according to any one of the preceding method-related embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0112] Preferably in conjunction with the dependent claims, further optional features and embodiments of the present invention are disclosed in more detail in the subsequent description of the preferred embodiments. Wherein, as will be appreciated by those skilled in the art, each optional feature can be implemented in an isolated manner as well as in any feasible combination. It is emphasized here that the scope of the present invention is not limited by the preferred embodiments.

[0113] In the attached picture:

[0114] Figure 1 A preferred embodiment of a spectacle lens for use with at least one eye of a user under a first illumination is presented; and

[0115] Figure 2 Preferred embodiments of spectacle lenses for at least one eye of a user under a second illumination are presented. DETAILED DESCRIPTION

[0116] Figure 1 and Figure 2 Each shows a preferred embodiment of a spectacle lens 110 for at least one eye 112 of a user 114. However, in the following, for simplicity, the drawings and their description only refer to one eye 112 of the user 114. In particular, the spectacle lens 110 can be a single vision lens, or alternatively, a progressive power lens, which is a power change lens with two optical power reference points and is generally designed to provide correction of presbyopia and clear vision from far to near. For further details on the progressive power, reference can be made to the description above.

[0117] The eyeglass lens 110 has a lens body 116 which may be transparent or at least partially transparent to an incident light beam 118 so as to be able to correct at least one eye aberration of the eye 112 of the user 114. Figure 1 and Figure 2 Schematically depicted, the lens body 116 includes a permanent mark 120 that corresponds to a two-dimensional structure on a surface 122 of the lens body 116, or a three-dimensional structure within the lens body 116. Figure 1 and Figure 2 Only a single permanent mark 120 is shown, but for purposes as described above or in more detail below, the lens body 116 may generally include more than one permanent mark 120. In particular, in contrast to temporary marks (not depicted here) that may also be disposed on the surface 122 of the lens body 116 and that typically include non-permanent inks and that may therefore be easily removed by applying a moderate, gentle force that is insufficient to damage the eyeglass lens 110, the permanent mark 120 can only be removed from the optical lens 110 by applying a considerable force that can damage the eyeglass lens 110.

[0118] In particular, each permanent mark 120 may be a volume element that is included by the lens body 116 and may occupy at most 2%, preferably at most 1%, and more preferably at most 0.5% of the volume of the lens body 116. In particular due to the transparency or partial transparency of the lens body 116, each permanent mark 120 may in principle be arranged at any position within the lens body 116, or at or below the surface 122 of the lens body 116.

[0119] As described in more detail above, each permanent mark 120 may preferably be configured to provide information about one or more locations on the lens body 116, about one or more information items related to the spectacle lens 110, or about one or more information items related to the eye 112 of the user 114. Herein, the information about one or more locations on the lens body 116 (which may be particularly useful for an optician to control the position of the spectacle lens 110 in front of the eye 112 of the user 114) may preferably include at least one of the following: a distance reference point (DRP); at least one near reference point (NRP); a fitting cross (FC); a prism reference point (PRP); an alignment reference mark. However, information about other kinds of locations is feasible. Further, the one or more information items related to the spectacle lens 110 may preferably include at least one of the following: a power, type, manufacturer or supplier of the spectacle lens 110; a trade name or trademark related to the spectacle lens 110. However, the permanent mark 120 may also include other information items related to the spectacle lens 110. Further, the one or more information items that can be associated with at least one eye 112 of the user 114 can preferably include at least one of the following: eye aberrations, in particular at least one refractive error; viewing direction; corneal vertex distance; or pupil distance. However, the at least one permanent mark 120 can also include other information items associated with at least one eye 112 of the user 114.

[0120] According to the present invention, the permanent mark 120 is or includes a diffraction structure 124. As described above, the diffraction structure 124 refers to a two-dimensional structure on the surface 122 of the lens body 116 or a three-dimensional structure within the lens body 110, wherein the structure is configured to generate a diffraction pattern (not depicted here) as long as (i) the incident light beam 118 is incident on the diffraction structure 124 and (ii) at least one specified condition is met. Herein, the diffraction pattern can be any kind of diffraction pattern, including but not limited to a holographic pattern.

[0121] As shown here, Figure 1 1 shows a first case where the at least one specified condition is not met. Although the permanent mark 120 is or includes a diffractive structure 124, it is therefore unable to generate a diffraction pattern. As a result, as indicated by arrow 130, the incident light beam 118 passes through the permanent mark 120 that is or includes the diffractive structure 124 in an unchanged manner. Therefore, the permanent mark 120 can remain invisible to the eye 112 of the user 114 of the eyeglass lens 110 and to an observer 128 (such as an optician) who does not use a specially selected optical aid to look at the diffractive structure 124 in the eyeglass lens 110 worn by the user 114 (such as in Figure 2The eye 126 (schematically depicted in FIG. 1 ) may also be invisible. As an alternative (not depicted here), a specifically designated optical sensor may be used to sense the diffractive structure 124 in the eyeglass lens 110.

[0122] Herein, the first situation in which the at least one specified condition is not met can be achieved by using a first illumination 132 to illuminate the eyeglass lens 110. Figure 1 As further shown, the first illumination 132 can preferably be provided by a large bandwidth light source 134, in particular a natural light source 136, such as the sun 138. As an alternative (not depicted here), an artificial light source typically used for general lighting purposes can also be used. Here, the artificial large bandwidth light source 134 can be selected in particular from white light emitting diodes, energy-saving lamps, incandescent lamps or gas discharge lamps, as long as such light source has a large bandwidth and can be generally used for general lighting purposes.

[0123] In contrast, Figure 2 A second case in which the at least one specified condition is satisfied is shown. Herein, the permanent mark 120 as or including the diffractive structure 124 can thus generate a desired diffraction pattern. As a result, the incident light beam 118 incident on the diffractive structure 124 included in the permanent mark 120 is diffracted by the diffractive structure 124 to generate an additional light beam 140 (also referred to as an "exit light beam") while a portion of the incident light beam 118 can still be transmitted in an unchanged manner at Figure 1 and Figure 2 110 . Thus, while the permanent mark 120 may remain invisible to the eye 112 of the user 114 of the spectacle lens 110 because the light beam indicated by the arrow 130 does not encounter the eye 112 of the user 114, the permanent mark 120 may become visible to the eye 126 of a bystander 128 (e.g., an optician) looking at the diffractive structure 124 included by the lens body 116 of the spectacle lens 110 from a specifically selected viewing direction 142. In certain embodiments (not depicted here), the permanent mark 120 may only become visible to the eye 126 of a bystander 128 (e.g., an optician) looking at the diffractive structure 124, provided that the bystander may insert at least one additional optical element (e.g., a filter) into the light path between the lens body 116 of the spectacle lens 110 and at least one eye 126 of the bystander 128. As described above, a specifically designated optical sensor may alternatively be used to sense the diffractive structure 124 in the spectacle lens 110. As Figure 2 As further shown, the diffractive structure 124 can be specified to be visible only when the second illumination 132 is at an angle of at most 45°, preferably at most 30°, more preferably at most 15° relative to the surface 122 of the eyeglass lens 110. Figure 2It is further shown that the diffractive structure 124 can be specified in such a way that the outgoing light beam 140 can have an angle of maximum 45°, preferably maximum 30°, more preferably maximum 15° relative to the surface 122 of the eyeglass lens 110, in order to specifically further limit the visibility of the diffraction pattern in this way. Figure 2 It may be suggested that the user 114 is actually wearing the spectacle lens 110 , but the visibility of the diffraction pattern is not affected thereby, and this would also occur if the user 114 was not wearing the spectacle lens 110 .

[0124] Herein, the second situation of satisfying the at least one specified condition can be achieved by using a second illumination 144 to illuminate the eyeglass lens 110. Figure 2 It is further shown that the second illumination 144 can preferably be provided by a small bandwidth light source 146, which can preferably be selected from a small bandwidth artificial light source (especially a laser light source 148) or a single light emitting diode 150. Herein, the small bandwidth light source 146 can especially include a spectral band with a wavelength range of maximum 150nm, preferably maximum 100nm, more preferably maximum 50nm.

[0125] In particular, by adjusting the second illumination 144 for the diffractive structure 124 in the eyeglass lens 110, the intensity of the light beam indicated by the arrow 130 that passes through the diffractive structure 124 in an otherwise unchanged manner can be reduced, preferably below the visibility threshold of the eye 112 of the user 114. In order to increase the difference between the invisibility and visibility of the diffraction pattern, the diffractive structure 124 can exhibit a reflection efficiency of only 10% to 50%, preferably 15% to 30%, under the second illumination 144 of the eyeglass lens 110. Alternatively or additionally, the small bandwidth light source 146 can be configured to generate light in at least one of the near infrared spectral region and the near ultraviolet spectral region in order to further reduce the visibility of the diffraction pattern in the visible spectral region.

[0126] Reference numerals list

[0127] 110 Eyeglass lenses

[0128] 112 Eyes

[0129] 114 users

[0130] 116 lens body

[0131] 118 Incident beam

[0132] 120 Permanent Marker

[0133] 122 Surface

[0134] 124 Diffraction structure

[0135] 126 Eyes

[0136] 128 Spectator (Optician)

[0137] 130 Arrow

[0138] 132 The First Lighting

[0139] 134 Wide Bandwidth Light Source

[0140] 136 Natural light source

[0141] 138 Sun

[0142] 140 Additional beam (outgoing beam)

[0143] 142 Viewing direction

[0144] 144 Second Lighting

[0145] 146 Small bandwidth light source

[0146] 148 Laser light source

[0147] 150 single LEDs

Claims

1. A spectacle lens (110) for at least one eye (112) of a user (114), the spectacle lens having a lens body (116), the lens body comprising at least one permanent marking (120), wherein: The at least one permanent marking (120) is or includes at least one diffractive structure (124), wherein at least one diffractive pattern generated by illuminating the diffractive structure (124) is designated as not visible under a first illumination (132) and is designated as visible only under a second illumination (144), wherein visible is a property of the at least one diffractive pattern being perceived by at least one eye of a person, and wherein invisible is a property of the at least one diffractive pattern not being perceived by at least one eye of the person, wherein the person is the user (114) or a bystander (128), It is characterized in that The at least one diffraction pattern is designated to be visible only under illumination in at least one of a near infrared spectral region and a near ultraviolet spectral region, wherein the at least one permanent mark (120) is configured to provide information about at least one of the locations on the lens body (116), wherein the information about the at least one location on the lens body (116) is selected from at least one of the following: - far reference point; - at least one near reference point; - Spectacle cross; - Prism reference point; or - Alignment reference marks, wherein the first illumination (132) of the eyeglass lens (110) is provided by a wide bandwidth light source (134), The second illumination (144) of the eyeglass lens (110) is provided by a small bandwidth light source (146), wherein the small bandwidth light source (146) is configured to generate light in at least one of a near infrared spectral region and a near ultraviolet spectral region.

2. The eyeglass lens (110) according to claim 1, wherein: The wide bandwidth light source (134) has a wavelength range above 150 nm.

3. The eyeglass lens (110) according to claim 2, wherein: The wide bandwidth light source (134) is selected from a natural light source (136) or an artificial light source used for general lighting purposes.

4. The spectacle lens (110) according to any one of claims 1 to 3, wherein: The narrow bandwidth light source (146) has a wavelength range of maximum 150 nm.

5. The eyeglass lens (110) according to claim 4, wherein: The narrow bandwidth light source (146) includes a spectral band having a wavelength range of up to 150 nm.

6. The spectacle lens (110) according to any one of claims 1 to 3, wherein: The at least one diffraction pattern is designed to be visible only when the second illumination (144) is at an angle of at most 45° relative to the surface (122) of the spectacle lens (110) and / or when viewed through at least one further optical element.

7. The spectacle lens (110) according to any one of claims 1 to 3, wherein: The at least one diffractive structure (124) is designed to generate at least one holographic pattern when the spectacle lens (110) is subjected to the second illumination (144).

8. The spectacle lens (110) according to any one of claims 1 to 3, wherein: The at least one permanent mark (120) is configured to provide information about an information item related to the eyeglass lens (110) or an information item related to at least one eye (112) of the user (114).

9. The spectacle lens (110) according to any one of claims 1 to 3, wherein: The at least one diffractive structure (124) is a volume element encompassed by the lens body (116), the volume element occupying at most 2% of the volume of the lens body (116).

10. A method for producing a spectacle lens (110) for at least one eye (112) of a user (114), wherein: The method comprises the following steps: a) generating an eyeglass lens (110) based on instructions configured to compensate for at least one eye aberration of at least one eye (112) of the user (114); and b) introducing at least one permanent marking (120) into the lens body (116) of the spectacle lens (110), wherein the at least one permanent mark (120) is introduced into the lens body (116) in such a way that the at least one permanent mark (120) is or comprises at least one diffractive structure (124), wherein at least one diffractive pattern generated by illuminating the diffractive structure (124) is designated as not visible under a first illumination (132) and as visible only under a second illumination (144), wherein visible is a property of the at least one diffractive pattern being perceived by at least one eye of a person, and wherein invisible is a property of the at least one diffractive pattern not being perceived by at least one eye of the person, wherein the person is the user (114) or a bystander (128), It is characterized in that The at least one diffraction pattern is designated as visible only under illumination in at least one of a near infrared spectral region and a near ultraviolet spectral region, wherein the at least one permanent mark (120) is configured to provide information about at least one of the locations on the lens body (116), wherein the information about the at least one location on the lens body (116) is selected from at least one of the following: - far reference point; - at least one near reference point; - Spectacle cross; - Prism reference point; or - Alignment reference marks, wherein the first illumination (132) of the eyeglass lens (110) is provided by a wide bandwidth light source (134), The second illumination (144) of the eyeglass lens (110) is provided by a small bandwidth light source (146), wherein the small bandwidth light source (146) is configured to generate light in at least one of a near infrared spectral region and a near ultraviolet spectral region.

11. The method according to claim 10, wherein: The at least one diffractive structure (124) is generated by at least one of: - embedding a photosensitive layer into the lens body (116) and irradiating the photosensitive layer; - treating the surface (122) of the lens body (116) by a surface treatment method selected from additive technology or subtractive technology; - modifying the refractive index within at least one volume element of the lens body (116).

12. A computer program product comprising executable instructions for performing a method for producing a spectacle lens (110) for at least one eye (112) of a user (114), wherein: The method comprises the following steps: a) generating an eyeglass lens (110) based on instructions configured to compensate for at least one eye aberration of at least one eye (112) of the user (114); and b) introducing at least one permanent marking (120) into the lens body (116) of the spectacle lens (110), wherein the at least one permanent mark (120) is introduced into the lens body (116) in such a way that the at least one permanent mark (120) is or comprises at least one diffractive structure (124), wherein at least one diffractive pattern generated by illuminating the diffractive structure (124) is designated as not visible under a first illumination (132) and as visible only under a second illumination (144), wherein visible is a property of the at least one diffractive pattern being perceived by at least one eye of a person, and wherein invisible is a property of the at least one diffractive pattern not being perceived by at least one eye of the person, wherein the person is the user (114) or a bystander (128), It is characterized in that The at least one diffraction pattern is designated to be visible only under illumination in at least one of a near infrared spectral region and a near ultraviolet spectral region, wherein the at least one permanent mark (120) is configured to provide information about at least one of the locations on the lens body (116), wherein the information about the at least one location on the lens body (116) is selected from at least one of the following: - far reference point; - at least one near reference point; - Spectacle cross; - Prism reference point; or - Alignment reference marks, wherein the first illumination (132) of the eyeglass lens (110) is provided by a wide bandwidth light source (134), The second illumination (144) of the eyeglass lens (110) is provided by a small bandwidth light source (146), wherein the small bandwidth light source (146) is configured to generate light in at least one of a near infrared spectral region and a near ultraviolet spectral region.

13. An eyeglass lens (110) for at least one eye (112) of a user (114), the eyeglass lens having a lens body (116), the lens body comprising at least one permanent marking (120), wherein: The at least one permanent marking (120) is or includes at least one diffractive structure (124), wherein at least one diffractive pattern generated by illuminating the diffractive structure (124) is designated as not visible under a first illumination (132) and is designated as visible only under a second illumination (144), wherein visible is a property of the at least one diffractive pattern being perceived by at least one eye of a person, and wherein invisible is a property of the at least one diffractive pattern not being perceived by at least one eye of the person, wherein the person is the user (114) or a bystander (128), It is characterized in that The at least one diffraction pattern is designated to be visible only when the second illumination (144) is at an angle of at most 45° relative to the surface (122) of the spectacle lens (110), wherein the at least one permanent mark (120) is configured to provide information about at least one of the positions on the lens body (116), wherein the information about the at least one position on the lens body (116) is selected from at least one of the following: - far reference point; - at least one near reference point; - Spectacle cross; - Prism reference point; or - Alignment reference marks, wherein the first illumination (132) of the eyeglass lens (110) is provided by a wide bandwidth light source (134), The second illumination (144) of the eyeglass lens (110) is provided by a small bandwidth light source (146), wherein the small bandwidth light source (146) is configured to generate light in at least one of a near infrared spectral region and a near ultraviolet spectral region.

14. The spectacle lens (110) according to claim 13, wherein: The wide bandwidth light source (134) has a wavelength range above 150 nm.

15. The spectacle lens (110) according to claim 14, wherein: The wide bandwidth light source (134) is selected from a natural light source (136) or an artificial light source used for general lighting purposes.

16. The spectacle lens (110) according to any one of claims 13 to 15, wherein: The narrow bandwidth light source (146) has a wavelength range of maximum 150 nm.

17. The spectacle lens (110) according to claim 16, wherein: The narrow bandwidth light source (146) includes a spectral band having a wavelength range of up to 150 nm.

18. The spectacle lens (110) according to any one of claims 13 to 15, wherein: The at least one diffraction pattern is designed to be visible only when the second illumination (144) is at an angle of at most 30° relative to the surface (122) of the spectacle lens (110).

19. The spectacle lens (110) according to claim 18, wherein: The at least one diffraction pattern is designated to be visible only when the second illumination (144) is at an angle of at most 15° relative to the surface (122) of the spectacle lens (110).

20. The spectacle lens (110) according to any one of claims 13 to 15, wherein: The at least one diffractive structure (124) is designed to generate at least one holographic pattern when the spectacle lens (110) is subjected to the second illumination (144).

21. The spectacle lens (110) according to any one of claims 13 to 15, wherein: The at least one permanent mark (120) is configured to provide information about an information item related to the eyeglass lens (110) or an information item related to at least one eye (112) of the user (114).

22. The spectacle lens (110) according to any one of claims 13 to 15, wherein: The at least one diffractive structure (124) is a volume element encompassed by the lens body (116), the volume element occupying at most 2% of the volume of the lens body (116).

23. A method for producing a spectacle lens (110) for at least one eye (112) of a user (114), wherein: The method comprises the following steps: a) generating an eyeglass lens (110) based on instructions configured to compensate for at least one eye aberration of at least one eye (112) of the user (114); and b) introducing at least one permanent marking (120) into the lens body (116) of the spectacle lens (110), wherein the at least one permanent mark (120) is introduced into the lens body (116) in such a way that the at least one permanent mark (120) is or comprises at least one diffractive structure (124), wherein at least one diffractive pattern generated by illuminating the diffractive structure (124) is designated as not visible under a first illumination (132) and as visible only under a second illumination (144), wherein visible is a property of the at least one diffractive pattern being perceived by at least one eye of a person, and wherein invisible is a property of the at least one diffractive pattern not being perceived by at least one eye of the person, wherein the person is the user (114) or a bystander (128), It is characterized in that The at least one diffraction pattern is designated to be visible only when the second illumination (144) is at an angle of at most 45° relative to the surface (122) of the spectacle lens (110), wherein the at least one permanent mark (120) is configured to provide information about at least one of the positions on the lens body (116), wherein the information about the at least one position on the lens body (116) is selected from at least one of the following: - far reference point; - at least one near reference point; - Spectacle cross; - Prism reference point; or - Alignment reference marks, wherein the first illumination (132) of the eyeglass lens (110) is provided by a wide bandwidth light source (134), The second illumination (144) of the eyeglass lens (110) is provided by a small bandwidth light source (146), wherein the small bandwidth light source (146) is configured to generate light in at least one of a near infrared spectral region and a near ultraviolet spectral region.

24. The method according to claim 23, wherein: The at least one diffractive structure (124) is generated by at least one of: - embedding a photosensitive layer into the lens body (116) and irradiating the photosensitive layer; - treating the surface (122) of the lens body (116) by a surface treatment method selected from additive technology or subtractive technology; - modifying the refractive index within at least one volume element of the lens body (116).

25. A computer program product comprising executable instructions for performing a method for producing a spectacle lens (110) for at least one eye (112) of a user (114), wherein: The method comprises the following steps: a) generating an eyeglass lens (110) based on instructions configured to compensate for at least one eye aberration of at least one eye (112) of the user (114); and b) introducing at least one permanent marking (120) into the lens body (116) of the spectacle lens (110), wherein the at least one permanent mark (120) is introduced into the lens body (116) in such a way that the at least one permanent mark (120) is or comprises at least one diffractive structure (124), wherein at least one diffractive pattern generated by illuminating the diffractive structure (124) is designated as not visible under a first illumination (132) and as visible only under a second illumination (144), wherein visible is a property of the at least one diffractive pattern being perceived by at least one eye of a person, and wherein invisible is a property of the at least one diffractive pattern not being perceived by at least one eye of the person, wherein the person is the user (114) or a bystander (128), It is characterized in that The at least one diffraction pattern is designated to be visible only when the second illumination (144) is at an angle of at most 45° relative to the surface (122) of the spectacle lens (110), wherein the at least one permanent mark (120) is configured to provide information about at least one of the positions on the lens body (116), wherein the information about the at least one position on the lens body (116) is selected from at least one of the following: - far reference point; - at least one near reference point; - Spectacle cross; - Prism reference point; or - Alignment reference marks, wherein the first illumination (132) of the eyeglass lens (110) is provided by a wide bandwidth light source (134), The second illumination (144) of the eyeglass lens (110) is provided by a small bandwidth light source (146), wherein the small bandwidth light source (146) is configured to generate light in at least one of a near infrared spectral region and a near ultraviolet spectral region.

26. An eyeglass lens (110) for at least one eye (112) of a user (114), the eyeglass lens having a lens body (116), the lens body comprising at least one permanent marking (120), wherein: The at least one permanent marking (120) is or includes at least one diffractive structure (124), wherein at least one diffractive pattern generated by illuminating the diffractive structure (124) is designated as not visible under a first illumination (132) and is designated as visible only under a second illumination (144), wherein visible is a property of the at least one diffractive pattern being perceived by at least one eye of a person, and wherein invisible is a property of the at least one diffractive pattern not being perceived by at least one eye of the person, wherein the person is the user (114) or a bystander (128), It is characterized in that The at least one diffraction pattern is designated to be visible only under illumination in at least one of a near infrared spectral region and a near ultraviolet spectral region, wherein the at least one permanent mark (120) is configured to provide information about at least one of the locations on the lens body (116), wherein the information about the at least one location on the lens body (116) is selected from at least one of the following: - far reference point; - at least one near reference point; - Spectacle cross; - Prism reference point; or - Alignment reference marks, wherein the at least one diffractive structure is designated to be visible by a specifically designated optical sensor, wherein the first illumination (132) of the eyeglass lens (110) is provided by a wide bandwidth light source (134), The second illumination (144) of the eyeglass lens (110) is provided by a small bandwidth light source (146), wherein the small bandwidth light source (146) is configured to generate light in at least one of a near infrared spectral region and a near ultraviolet spectral region.

27. The spectacle lens (110) according to claim 26, wherein: The wide bandwidth light source (134) has a wavelength range above 150 nm.

28. The spectacle lens (110) according to claim 27, wherein: The wide bandwidth light source (134) is selected from a natural light source (136) or an artificial light source used for general lighting purposes.

29. The spectacle lens (110) according to any one of claims 26 to 28, wherein: The narrow bandwidth light source (146) has a wavelength range of maximum 150 nm.

30. The spectacle lens (110) according to claim 29, wherein: The narrow bandwidth light source (146) includes a spectral band having a wavelength range of up to 150 nm.

31. The spectacle lens (110) according to any one of claims 26 to 28, wherein: The at least one diffraction pattern is designed to be visible only when the second illumination (144) is at an angle of at most 45° relative to the surface (122) of the spectacle lens (110) and / or when viewed through at least one further optical element.

32. The spectacle lens (110) according to any one of claims 26 to 28, wherein: The at least one diffractive structure (124) is designed to generate at least one holographic pattern when the spectacle lens (110) is subjected to the second illumination (144).

33. The spectacle lens (110) according to any one of claims 26 to 28, wherein: The at least one permanent mark (120) is configured to provide information about an information item related to the eyeglass lens (110) or an information item related to at least one eye (112) of the user (114).

34. The spectacle lens (110) according to any one of claims 26 to 28, wherein: The at least one diffractive structure (124) is a volume element encompassed by the lens body (116), the volume element occupying at most 2% of the volume of the lens body (116).

35. A method for producing a spectacle lens (110) for at least one eye (112) of a user (114), wherein: The method comprises the following steps: a) generating an eyeglass lens (110) based on instructions configured to compensate for at least one eye aberration of at least one eye (112) of the user (114); and b) introducing at least one permanent marking (120) into the lens body (116) of the spectacle lens (110), wherein the at least one permanent mark (120) is introduced into the lens body (116) in such a way that the at least one permanent mark (120) is or comprises at least one diffractive structure (124), wherein at least one diffractive pattern generated by illuminating the diffractive structure (124) is designated as not visible under a first illumination (132) and as visible only under a second illumination (144), wherein visible is a property of the at least one diffractive pattern being perceived by at least one eye of a person, and wherein invisible is a property of the at least one diffractive pattern not being perceived by at least one eye of the person, wherein the person is the user (114) or a bystander (128), It is characterized in that The at least one diffraction pattern is designated to be visible only under illumination in at least one of a near infrared spectral region and a near ultraviolet spectral region, wherein the at least one permanent mark (120) is configured to provide information about at least one of the locations on the lens body (116), wherein the information about the at least one location on the lens body (116) is selected from at least one of the following: - far reference point; - at least one near reference point; - Spectacle cross; - Prism reference point; or - Alignment reference marks, wherein the at least one diffractive structure is designated to be visible by a specifically designated optical sensor, wherein the first illumination (132) of the eyeglass lens (110) is provided by a wide bandwidth light source (134), The second illumination (144) of the eyeglass lens (110) is provided by a small bandwidth light source (146), wherein the small bandwidth light source (146) is configured to generate light in at least one of a near infrared spectral region and a near ultraviolet spectral region.

36. The method of claim 35, wherein: The at least one diffractive structure (124) is generated by at least one of: - embedding a photosensitive layer into the lens body (116) and irradiating the photosensitive layer; - treating the surface (122) of the lens body (116) by a surface treatment method selected from additive technology or subtractive technology; - modifying the refractive index within at least one volume element of the lens body (116).

37. A computer program product comprising executable instructions for performing a method for producing a spectacle lens (110) for at least one eye (112) of a user (114), wherein: The method comprises the following steps: a) generating an eyeglass lens (110) based on instructions configured to compensate for at least one eye aberration of at least one eye (112) of the user (114); and b) introducing at least one permanent marking (120) into the lens body (116) of the spectacle lens (110), wherein the at least one permanent mark (120) is introduced into the lens body (116) in such a way that the at least one permanent mark (120) is or comprises at least one diffractive structure (124), wherein at least one diffractive pattern generated by illuminating the diffractive structure (124) is designated as not visible under a first illumination (132) and as visible only under a second illumination (144), wherein visible is a property of the at least one diffractive pattern being perceived by at least one eye of a person, and wherein invisible is a property of the at least one diffractive pattern not being perceived by at least one eye of the person, wherein the person is the user (114) or a bystander (128), It is characterized in that The at least one diffraction pattern is designated to be visible only under illumination in at least one of a near infrared spectral region and a near ultraviolet spectral region, wherein the at least one permanent mark (120) is configured to provide information about at least one of the locations on the lens body (116), wherein the information about the at least one location on the lens body (116) is selected from at least one of the following: - far reference point; - at least one near reference point; - Spectacle cross; - Prism reference point; or - Alignment reference marks, wherein the at least one diffractive structure is designated to be visible by a specifically designated optical sensor, wherein the first illumination (132) of the eyeglass lens (110) is provided by a wide bandwidth light source (134), The second illumination (144) of the eyeglass lens (110) is provided by a small bandwidth light source (146), wherein the small bandwidth light source (146) is configured to generate light in at least one of a near infrared spectral region and a near ultraviolet spectral region.

38. An eyeglass lens (110) for at least one eye (112) of a user (114), the eyeglass lens having a lens body (116), the lens body comprising at least one permanent marking (120), wherein: The at least one permanent marking (120) is or includes at least one diffractive structure (124), wherein at least one diffractive pattern generated by illuminating the diffractive structure (124) is designated as not visible under a first illumination (132) and is designated as visible only under a second illumination (144), wherein visible is a property of the at least one diffractive pattern being perceived by at least one eye of a person, and wherein invisible is a property of the at least one diffractive pattern not being perceived by at least one eye of the person, wherein the person is the user (114) or a bystander (128), It is characterized in that The at least one diffraction pattern is designated to be visible only under illumination in at least one of a near infrared spectral region and a near ultraviolet spectral region, wherein the at least one permanent mark (120) is configured to provide information about at least one of the locations on the lens body (116), wherein the information about the at least one location on the lens body (116) is selected from at least one of the following: - far reference point; - at least one near reference point; - Spectacle cross; - Prism reference point; or - Alignment reference marks, wherein an incident light beam incident on the lens body (116) outside the at least one diffraction pattern or incident on the at least one diffraction pattern and not including at least one wavelength in at least one of the near-infrared spectral region and the near-ultraviolet spectral region is transmitted in a manner that does not change the spectral distribution of the light beam, while an incident light beam incident on the at least one diffraction pattern and including at least one wavelength in at least one of the near-infrared spectral region and the near-ultraviolet spectral region changes the spectral distribution of the light beam, wherein the first illumination (132) of the eyeglass lens (110) is provided by a wide bandwidth light source (134), The second illumination (144) of the eyeglass lens (110) is provided by a small bandwidth light source (146), wherein the small bandwidth light source (146) is configured to generate light in at least one of a near infrared spectral region and a near ultraviolet spectral region.

39. The spectacle lens (110) according to claim 38, wherein: The wide bandwidth light source (134) has a wavelength range above 150 nm.

40. The spectacle lens (110) according to claim 39, wherein: The wide bandwidth light source (134) is selected from a natural light source (136) or an artificial light source used for general lighting purposes.

41. The spectacle lens (110) according to any one of claims 38 to 40, wherein: The narrow bandwidth light source (146) has a wavelength range of maximum 150 nm.

42. The spectacle lens (110) according to claim 41, wherein: The narrow bandwidth light source (146) includes a spectral band having a wavelength range of up to 150 nm.

43. The spectacle lens (110) according to any one of claims 38 to 40, wherein: The at least one diffraction pattern is designed to be visible only when the second illumination (144) is at an angle of at most 45° relative to the surface (122) of the spectacle lens (110) and / or when viewed through at least one further optical element.

44. The spectacle lens (110) according to any one of claims 38 to 40, wherein: The at least one diffractive structure (124) is designed to generate at least one holographic pattern when the spectacle lens (110) is subjected to the second illumination (144).

45. The spectacle lens (110) according to any one of claims 38 to 40, wherein: The at least one permanent mark (120) is configured to provide information about an information item related to the eyeglass lens (110) or an information item related to at least one eye (112) of the user (114).

46. ​​The spectacle lens (110) according to any one of claims 38 to 40, wherein: The at least one diffractive structure (124) is a volume element encompassed by the lens body (116), the volume element occupying at most 2% of the volume of the lens body (116).

47. A method for producing a spectacle lens (110) for at least one eye (112) of a user (114), wherein: The method comprises the following steps: a) generating an eyeglass lens (110) based on instructions configured to compensate for at least one eye aberration of at least one eye (112) of the user (114); and b) introducing at least one permanent marking (120) into the lens body (116) of the spectacle lens (110), wherein the at least one permanent mark (120) is introduced into the lens body (116) in such a way that the at least one permanent mark (120) is or comprises at least one diffractive structure (124), wherein at least one diffractive pattern generated by illuminating the diffractive structure (124) is designated as not visible under a first illumination (132) and as visible only under a second illumination (144), wherein visible is a property of the at least one diffractive pattern being perceived by at least one eye of a person, and wherein invisible is a property of the at least one diffractive pattern not being perceived by at least one eye of the person, wherein the person is the user (114) or a bystander (128), It is characterized in that The at least one diffraction pattern is designated to be visible only under illumination in at least one of a near infrared spectral region and a near ultraviolet spectral region, wherein the at least one permanent mark (120) is configured to provide information about at least one of the locations on the lens body (116), wherein the information about the at least one location on the lens body (116) is selected from at least one of the following: - far reference point; - at least one near reference point; - Spectacle cross; - Prism reference point; or - Alignment reference marks, wherein an incident light beam incident on the lens body (116) outside the at least one diffraction pattern or incident on the at least one diffraction pattern and not including at least one wavelength in at least one of the near-infrared spectral region and the near-ultraviolet spectral region is transmitted in a manner that does not change the spectral distribution of the light beam, while an incident light beam incident on the at least one diffraction pattern and including at least one wavelength in at least one of the near-infrared spectral region and the near-ultraviolet spectral region changes the spectral distribution of the light beam, wherein the first illumination (132) of the eyeglass lens (110) is provided by a wide bandwidth light source (134), The second illumination (144) of the eyeglass lens (110) is provided by a small bandwidth light source (146), wherein the small bandwidth light source (146) is configured to generate light in at least one of a near infrared spectral region and a near ultraviolet spectral region.

48. The method of claim 47, wherein: The at least one diffractive structure (124) is generated by at least one of: - embedding a photosensitive layer into the lens body (116) and irradiating the photosensitive layer; - treating the surface (122) of the lens body (116) by a surface treatment method selected from additive technology or subtractive technology; - modifying the refractive index within at least one volume element of the lens body (116).

49. A computer program product comprising executable instructions for performing a method for producing a spectacle lens (110) for at least one eye (112) of a user (114), wherein: The method comprises the following steps: a) generating an eyeglass lens (110) based on instructions configured to compensate for at least one eye aberration of at least one eye (112) of the user (114); and b) introducing at least one permanent marking (120) into the lens body (116) of the spectacle lens (110), wherein the at least one permanent mark (120) is introduced into the lens body (116) in such a way that the at least one permanent mark (120) is or comprises at least one diffractive structure (124), wherein at least one diffractive pattern generated by illuminating the diffractive structure (124) is designated as not visible under a first illumination (132) and as visible only under a second illumination (144), wherein visible is a property of the at least one diffractive pattern being perceived by at least one eye of a person, and wherein invisible is a property of the at least one diffractive pattern not being perceived by at least one eye of the person, wherein the person is the user (114) or a bystander (128), It is characterized in that The at least one diffraction pattern is designated to be visible only under illumination in at least one of a near infrared spectral region and a near ultraviolet spectral region, wherein the at least one permanent mark (120) is configured to provide information about at least one of the locations on the lens body (116), wherein the information about the at least one location on the lens body (116) is selected from at least one of the following: - far reference point; - at least one near reference point; - Spectacle cross; - Prism reference point; or - Alignment reference marks, wherein an incident light beam incident on the lens body (116) outside the at least one diffraction pattern or incident on the at least one diffraction pattern and not including at least one wavelength in at least one of the near-infrared spectral region and the near-ultraviolet spectral region is transmitted in a manner that does not change the spectral distribution of the light beam, while an incident light beam incident on the at least one diffraction pattern and including at least one wavelength in at least one of the near-infrared spectral region and the near-ultraviolet spectral region changes the spectral distribution of the light beam, wherein the first illumination (132) of the eyeglass lens (110) is provided by a wide bandwidth light source (134), The second illumination (144) of the eyeglass lens (110) is provided by a small bandwidth light source (146), wherein the small bandwidth light source (146) is configured to generate light in at least one of a near infrared spectral region and a near ultraviolet spectral region.

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