CONTACT LENS

Description

[0001] The invention relates to the field of ophthalmic optics.

[0002] It relates more particularly to an ophthalmic lens, one of the main faces of which includes an optical filter intended to reduce the effects of phototoxicity of blue light on the retina of a glasses wearer.

[0003] Throughout this patent application, reference will be made to ranges of values, in particular wavelengths and angles of incidence. The expression "between the values x And y » means “in the range of x has y ", the terminals x And y being included in this range.

[0004] The light visible to the human eye spans a wavelength from about 380 nanometers (nm) to 780 nm. The portion of this spectrum between about 380 nm and 500 nm is essentially blue, high-energy light.

[0005] Numerous studies (see for example Kitchel E., "The effects of blue light on ocular health", Journal of Visual Impairment and Blindness Vol. 94, No. 6, 2000 or Glazer-Hockstein et al., Retina, Vol. 26, No. 1, pp. 1-4, 2006) suggest that blue light has phototoxic effects on the eye, and particularly on the retina.

[0006] Indeed, ocular photobiology studies (Algvere PV et al., “Age-Related Maculopathy and the Impact of the Blue Light Hazard,” Acta Ophthalmo. Scand., Vol. 84, pp. 4-15, 2006) and clinical studies (Tomany SC et al., “Sunlight and the 10-Year Incidence of Age-Related Maculopathy. The Beaver Dam Eye Study,” Arch Ophthalmol., Vol. 122, pp. 750-757, 2004) have shown that exposure to blue light that is too long or too intense can induce severe ophthalmic pathologies such as age-related macular degeneration (AMD).

[0007] However, part of this blue light, between approximately 465 nm and 495 nm, is beneficial insofar as it intervenes in the mechanisms regulating biological rhythms, called “circadian cycles”.

[0008] Therefore, it is recommended to limit exposure to potentially harmful blue light, particularly for the wavelength band which presents increased danger (see in particular table B1 of the ISO 8980-3:2003 (E) standard concerning the danger function of blue light B(λ)).

[0009] For this purpose, it may be advisable to wear an ophthalmic lens in front of each eye that prevents or limits the transmission of phototoxic blue light to the retina.

[0010] It has already been proposed, for example in patent application WO2008024414, to at least partially cut off the troublesome part of the blue light spectrum from 400 nm to 460 nm by means of lenses comprising a film partially inhibiting the light in the desired wavelength range, by absorption or by reflection.

[0011] Furthermore, those skilled in the art are looking for filters that can minimize the amount of harmful blue light received by the retina, while still allowing visible light to be transmitted efficiently for wavelengths above 465 nm in order, on the one hand, to maintain good vision for the wearer and, on the other hand, not to alter circadian cycles.

[0012] The difficulty is that the wavelength ranges from 420 nm to 450 nm that need to be filtered are very close to the wavelength ranges that should not be filtered, or only very little.

[0013] It is an objective of the invention to provide an ophthalmic lens comprising a reflection filter taking into account all the light irradiation coming from the surrounding environment and reducing the blue light received by the eye in the wavelength range from 420 nm to 450 nm.

[0014] Another object of the invention is to provide an ophthalmic lens comprising such a reflection filter which allows excellent transmission in the wavelength range from 465 nm to 495 nm.

[0015] Another objective of the invention is to provide an ophthalmic lens comprising a reflection filter having the above properties, which is easy and inexpensive to implement industrially.

[0016] Generally speaking, it is possible to design so-called "narrow" filters that are highly selective, with a limited bandwidth and a reflectivity peak centered on this bandwidth. To limit the transmission of phototoxic blue light to the retina, a suitable narrow filter should have, for example, a half-width of 30 nm between 420 nm and 450 nm, and a maximum reflectivity for the central wavelength of 435 nm.

[0017] In practice, highly selective narrow filters are generally made up of a stack comprising a large number of dielectric layers and whose total thickness is high.

[0018] Such filters are time-consuming and expensive to produce industrially, especially when they are deposited under vacuum. The increase in the number of layers and the increase in interfaces also makes it difficult to achieve good mechanical properties.

[0019] Taking into account the above constraints leads to limiting the number of layers, which has the consequence of limiting the performances in terms of spectral selectivity (the width at half-maximum of such a narrow filter can then reach up to 70 nm) and angular selectivity, the filter becoming weakly angularly selective. This means that if, for wavelengths between 420 nm and 450 nm, the reflectivity of the main face of an ophthalmic lens equipped with such a narrow filter is high for angles of incidence on this main face between 0° and 15°, then the reflectivity for angles of incidence between 30° and 45° on this same main face will also be relatively high.

[0020] The angle of incidence is classically defined as the angle between the normal to the surface at the point of incidence and the direction of the light beam contacting this surface.

[0021] This has a number of consequences for a wearer of glasses equipped with ophthalmic lenses on the main front face of which a narrow optical filter as described above has been deposited. Here, the main front face of the ophthalmic lens is the main face of the ophthalmic lens which is located furthest from the eyes of the wearer of glasses. In contrast, the main face of the ophthalmic lens which is located closest to the eyes of the wearer will be referred to as the main rear face.

[0022] Thus positioned in relation to the wearer's eyes, the ophthalmic lenses receive, on the one hand, "direct" light incident on the main front faces of the ophthalmic lenses, and, on the other hand, "indirect" light coming from the back of the wearer and reflected by the ophthalmic lenses.

[0023] Light coming from behind the wearer and reflected by the ophthalmic lens towards the wearer's eye is mainly light incident on the rear main face of the ophthalmic lens with angles of incidence between 30° and 45°.

[0024] This visible light coming from the rear of the wearer at an angle of incidence between 30° and 45° passes through the rear main face, on which a first reflection occurs, then the substrate to reach the front main face comprising said filter.

[0025] Furthermore, it is known that the optical properties of a filter deposited on the main front face of an ophthalmic lens, for example the reflectivity, are equivalent, whether the light is incident from the side of the main front face or coming from the side of the main rear face.

[0026] If the narrow filter effectively reflects blue light with a wavelength between 420 nm and 450 nm for an angle of incidence on the main front face of between 30° and 45°, then it also effectively reflects this blue light arriving from the rear, for an angle of incidence between 30° and 45° on the main rear face.

[0027] Thus, even though direct light incident on the front main faces of ophthalmic lenses is effectively rejected by reflection off the narrow filters deposited on the front main faces, indirect light coming from behind the wearer is reflected just as effectively back to the wearer's eyes.

[0028] Ultimately, despite the use of a narrow filter, the amount of phototoxic blue light reaching the wearer's retina could be relatively high and present a danger to the wearer.

[0029] Furthermore, the filter, whether applied to the front or rear face, behaves in the same way with respect to light in the wavelength range from 420 nm to 450 nm, since the ophthalmic lens, in either case, transmits light in the wavelength range from 420 nm to 450 nm. The same harmful consequence with respect to phototoxic blue light therefore occurs for the wearer if the filter, instead of being applied to the main front face of the ophthalmic lens, is applied to the main rear face.

[0030] Furthermore, as already mentioned previously, narrow reflective filters with a limited number of layers and a thickness compatible with large-scale industrial manufacturing exhibit only reduced spectral selectivity, and are likely to reflect a significant portion of the light in the range governing circadian cycles.

[0031] In order to meet the objectives of the invention and to remedy the aforementioned drawbacks of the state of the art, the present invention proposes an ophthalmic lens provided with a reflection filter making it possible to reduce the quantity of phototoxic blue light reaching the retina of a wearer of this ophthalmic lens, while preserving the circadian cycles as much as possible.

[0032] To this end, the invention relates to an ophthalmic lens having a main front face and a main rear face, at least one of the main faces comprising a filter which gives the main face comprising said filter the following properties: an average blue reflection factor (R m,B ) over a wavelength range from 420 nanometers to 450 nanometers which is greater than or equal to 5%, for an angle of incidence between 0° and 15°, a spectral reflectivity curve for an angle of incidence between 0° and 15°, this reflectivity curve having: a maximum reflectivity at a wavelength less than 435 nanometers, and a full width at half maximum (FWHM) greater than 80 nanometers, the reflectivity value at the maximum reflectivity of the main face comprising said filter, for an angle of incidence of 15°, is at least 1.5 times greater than the reflectivity value of this same main face, at the wavelength of 435 nm and for an angle of incidence of 15°, and for an angle of incidence θ between 0° and 15° and for an angle of incidence θ' between 30° and 45°, a parameter Δ(θ,θ') defined by the relation Δ(θ,θ') = 1 - [ R θ' (435 nm) / R θ (435 nm) ],such that this parameter Δ(θ,θ') is greater than or equal to 0.6, where R θ (435 nm) represents the value of the reflectivity of the main face comprising said filter, at the wavelength of 435 nanometers for the angle of incidence θ, and R θ' (435 nm) represents the value of the reflectivity of the main face comprising said filter at the wavelength of 435 nanometers for the angle of incidence θ'.

[0033] In another embodiment, the invention relates to an ophthalmic lens having a front main face and a rear main face, at least one of the main faces comprising a filter which gives the main face comprising said filter the following properties: an average blue reflection factor (R m,B ) over a wavelength range from 420 nanometers to 450 nanometers which is greater than or equal to 10%, for an angle of incidence between 0° and 15°, a spectral reflectivity curve for an angle of incidence between 0° and 15°, this reflectivity curve having: a maximum reflectivity at a wavelength less than 435 nanometers, and a full width at half maximum (FWHM) greater than or equal to 70 nanometers, preferably greater than or equal to 75 nm, and for an angle of incidence θ between 0° and 15° and for an angle of incidence θ' between 30° and 45°, a parameter Δ(θ,θ') defined by the relation Δ(θ,θ') = 1 - [ R θ' (435 nm) / R θ (435 nm) ], such that this parameter Δ(θ,θ') is greater than or equal to 0.5, where R θ (435 nm) represents the value of the reflectivity of the main face comprising said filter at the wavelength of 435 nanometers for the angle of incidence θ,and R θ' (435 nm) represents the value of the reflectivity of the main face comprising said filter at the wavelength of 435 nanometers for the angle of incidence θ' and for an angle of incidence between 0° and 15°, a parameter Δ spectral defined by the relation Δ spectral = 1 - [ R 0°-15° (480 nm) / R 0°-15° (435 nm) ], such that this parameter Δ spectral is greater than or equal to 0.8, where R 0°-15° (480 nm) represents the value of the reflectivity of the front main face at the wavelength of 480 nanometers at the incidence considered, and R 0°-15° (435 nm) represents the value of the reflectivity of the front main face at the wavelength of 435 nanometers at the incidence considered.

[0034] Thus, the ophthalmic lens according to the invention makes it possible to minimize the transmission of phototoxic blue light to the retina of a wearer of this ophthalmic lens, thanks, on the one hand, to its average reflectivity over a range of wavelengths from 420 nm to 450 nanometers and thanks, on the other hand, to its angular selectivity.

[0035] Indeed, the ophthalmic lens provided with said filter has, at a given wavelength, a substantially different reflectivity for two angles of incidence on the main face comprising said filter which are substantially different.

[0036] Furthermore, this filter is offset from the phototoxic blue light wavelength band between 420 nanometers and 450 nanometers. Indeed, the ophthalmic lens has a maximum reflectivity at a wavelength below 435 nanometers. This then makes it possible to adjust the angular selectivity of the lens.

[0037] The spectral characteristics (reflectivity, R m , R v , etc.) of each main face of an ophthalmic lens according to the invention are determined in a conventional manner for an incident light beam arriving on the main face from the air, without having passed through the substrate.

[0038] Finally, an ophthalmic lens according to the invention having a parameter Δ(θ,θ') as defined above allows: to maximize the reflection of phototoxic blue light coming from the side of the front main face, the intensity of this reflection being linked to the quantity R θ (435 nm), and to minimize the reflection of phototoxic blue light coming from the side of the rear main face, the intensity of this reflection being linked to the quantity R θ' (435 nm).

[0039] Thus, the ophthalmic lens according to the invention, equipped with its filter, reduces the overall transmission of phototoxic blue light to the retina of a wearer of such an ophthalmic lens.

[0040] Since the proposed filter has a greater width at half height than a narrow filter, it is less thick than such a narrow filter and comprises fewer layers, and is therefore easier and less expensive to manufacture than a narrow filter.

[0041] Furthermore, other advantageous and non-limiting characteristics of the ophthalmic lens according to the invention are the following: the filter is formed on the front main face of the ophthalmic lens; the parameter Δ(θ,θ') is defined for an angle of incidence θ on the main face comprising said filter such that θ = 15° and for an angle of incidence θ' on the main face comprising said filter such that θ' = 45°; the spectral parameter Δ is defined for an angle of incidence of 15°; the parameter Δ(θ,θ') is greater than or equal to 0.65, better still greater than or equal to 0.7, better still greater than or equal to 0.75, and optimally greater than or equal to 0.8; the maximum reflectivity is at a wavelength less than or equal to 410 nm, better still less than or equal to 400 nm, and even better still less than or equal to 390 nm; the maximum reflectivity is at a wavelength greater than or equal to 350 nanometers, preferably in the wavelength range from 360 nm to 400 nm, more preferably in the wavelength range from 370 nm to 390 nm;the width at half maximum is greater than or equal to 90 nanometers, preferably greater than or equal to 100 nanometers; the width at half maximum is less than or equal to 150 nanometers, preferably less than or equal to 120 nanometers, better still less than or equal to 110 nm.;

[0042] Thus, the full width at half maximum is generally between 80 nm and 150 nm, preferably between 90 nm and 120 nm, more preferably between 90 nm and 110 nm and more preferably between 100 nm and 110 nm.

[0043] Finally, other advantageous and non-limiting characteristics of the ophthalmic lens according to the invention are the following: the value of the reflectivity at the maximum reflectivity of the main face comprising the filter, for an angle of incidence of 15°, is preferably at least 1.5 times greater, better still at least 2 times greater and optimally at least 2.5 times greater than the value of the reflectivity of this same main face, for the same angle of incidence, and at the wavelength of 435 nm;the ratio [ R 15° (435 nm) - R 15° (480 nm) ] / R 15° (435 nm) where R 15° (435 nm) and R 15° (480 nm) respectively represent the reflectivity of the main face of the ophthalmic lens comprising said filter at a wavelength of 435 nm and at a wavelength of 480 nm, for an angle of incidence on this main face of 15°, is greater than or equal to 0.8, better still greater than or equal to 0.85 and even better still greater than or equal to 0.9. This ratio characterizes the excellent selectivity of the filter equipping the ophthalmic lens according to the invention which makes it possible to protect from the phototoxic band without disturbing the chronobiological band; the average light reflection factor (R v ) on the main face of the ophthalmic lens comprising the filter is less than or equal to 2.5%, preferably less than or equal to 1.5%;the average light reflection factor (R v ) on each of the main faces of the ophthalmic lens is less than or equal to 2.5%, preferably less than or equal to 1.5%; the average light reflection factor (R v ) on the main face of the ophthalmic lens comprising the filter is less than or equal to 0.7%; the filter is formed on the front main face of the ophthalmic lens and the average reflection factor (unweighted) in the ultraviolet (UV) range from 300 nm to 380 nm, for an angle of incidence on this front main face of 15°, is greater than or equal to 15%, better still greater than or equal to 20% and even better still greater than or equal to 25%; the filter is an interference filter; the filter comprises a number of layers less than or equal to 11, preferably from 2 to 10 layers, and even more preferably from 4 to 9 layers and even better still from 4 to 7 layers;the filter has a total thickness less than or equal to 700 nanometers, preferably less than or equal to 600 nanometers, and better still less than or equal to 550 nm, and optimally from 200 nm to 400 nm; the main rear face of the ophthalmic lens has an anti-UV coating, i.e. reflecting little UV, preferably an anti-reflective coating effective in UV and visible light.;

[0044] Furthermore, the ophthalmic lens according to the invention is advantageously used in the production of a pair of glasses.

[0045] Thus, the invention also provides a pair of glasses comprising at least one ophthalmic lens according to the invention.

[0046] According to one of its aspects, the invention relates to the use of an ophthalmic lens according to the invention to increase the contrast of vision of a wearer. The use of lenses according to the invention thus makes it possible to improve the wearer's visual comfort, and in particular to more easily recognize objects or people observed through said ophthalmic lens. This use will be of interest to any subject, in particular to a healthy subject not presenting ocular pathologies or predisposition to such a pathology.

[0047] Furthermore, the use of an ophthalmic lens according to the invention proves to be particularly interesting for therapeutic use or for preventing diseases linked to the phototoxicity of blue light.

[0048] The invention therefore also relates to the use of an ophthalmic lens according to the invention to reduce the risks of the appearance of an ophthalmic pathology due to a degenerative process due to the phototoxicity of blue light.

[0049] The invention finally proposes the use of an ophthalmic lens according to the invention to protect at least part of a wearer's eye from the phototoxicity of blue light, in particular to protect it from a degenerative process such as age-related macular degeneration (AMD).

[0050] The invention will be described in more detail with reference to the accompanying drawings, in which ophthalmic lenses have a filter according to the invention on their front main face: THE figures 1 to 3present the spectral reflectivity curves for an angle of incidence on the main front face of 15°, of certain ophthalmic lenses prepared in examples 1 to 3 of the present application and of ophthalmic lenses coated with a filter not satisfying the characteristics of the filters of the invention, in particular the width at half-height (see comparative examples C1, C2, and C3). figure 4 presents for each of the previous examples the weighted transmission factor (in %) and the weighted rear reflectivity (in %), the weighting being done using the blue light risk function. Figure 5 represents the spectral reflectivity curves between 380 nm and 500 nm of the ophthalmic lens of example 3 of the present application for angles of incidence on the front main face of 0° and 45°.

[0051] As is well known, the ophthalmic lens according to the invention comprises a transparent substrate made of mineral or organic glass. This substrate may comprise one or more functional coatings to give the ophthalmic lens particular optical and / or mechanical properties, such as, for example, an anti-impact coating, an anti-abrasion coating, an anti-reflective coating, an anti-UV coating, an anti-static coating, a polarizing coating, and an anti-fouling and / or anti-fog coating. All these coatings are well known in the art of ophthalmic lenses.

[0052] The substrate of the ophthalmic lens according to the invention is preferably made of organic glass, for example a thermoplastic or thermosetting plastic material.

[0053] Thermoplastic materials suitable for substrates include (meth)acrylic (co)polymers, in particular poly(methyl methacrylate) (PMMA), thio(meth)acrylic (co)polymers, polyvinyl butyral (PVB), polycarbonates (PC), polyurethanes (PU), poly(thiourethanes), polyol allylcarbonate (co)polymers, thermoplastic ethylene / vinyl acetate copolymers, polyesters such as polyethylene terephthalate (PET) or poly(butylene terephthalate) (PBT), polyepisulfides, polyepoxides, polycarbonate / polyester copolymers, cycloolefin copolymers such as ethylene / norbornene or ethylene / cyclopentadiene copolymers and combinations thereof.

[0054] By (co)polymer is meant a copolymer or a homopolymer. By (meth)acrylate is meant an acrylate or a methacrylate. By polycarbonate (PC), for the purposes of the present invention, is meant both homopolycarbonates and copolycarbonates and block copolycarbonates.

[0055] Particularly recommended substrates are substrates obtained by (co)polymerization of diethylene glycol bis allyl carbonate, sold, for example, under the trade name CR-39 ®< by the company PPG Industries (ORMA ®< ESSILOR lenses), or by polymerization of thio(meth)acrylic monomers, such as those described in French patent application FR 2734827. The substrates can be obtained by polymerization of mixtures of the above monomers, or can also comprise mixtures of these polymers and (co)polymers.

[0056] Other preferred substrates are polycarbonates.

[0057] The ophthalmic lens has a main front face and a main rear face.

[0058] The back principal surface is the principal surface that, when using the ophthalmic lens, is closest to the user's eye. This is usually a concave surface. Conversely, the front principal surface is the principal surface that, when using the ophthalmic lens, is furthest from the user's eye. This is usually a convex surface.

[0059] According to the invention, at least one of the main faces of the ophthalmic lens comprises a filter.

[0060] As previously stated, the substrate of the ophthalmic lens may have different coatings either on the front main face of the ophthalmic lens or on the back main face of the ophthalmic lens.

[0061] A coating that is "on" the substrate or has been deposited "on" the substrate is defined as a coating that: (i) is positioned above a main face of the substrate, (ii) is not necessarily in contact with the substrate, i.e. one or more intermediate coatings may be disposed between the substrate and the coating in question, and (iii) does not necessarily completely cover the main face of the substrate.

[0062] When "a layer A is located under a layer B", we will understand that layer B is further from the substrate than layer A.

[0063] In one embodiment, the filter is formed directly on the front major face of the ophthalmic lens.

[0064] In another preferred embodiment, it is deposited directly on an anti-abrasion and / or anti-scratch coating which has itself been deposited on the main front face of the ophthalmic lens.

[0065] Before depositing the filter, it is common to subject the surface of said substrate to a physical or chemical activation treatment, intended to increase the adhesion of the filter on the main face(s).

[0066] This pretreatment is usually carried out under vacuum. It can involve bombardment with energetic species, for example an ion beam (" Ion Pre-Cleaning » or "IPC") or electron beam, corona discharge treatment, corona discharge treatment, UV treatment, or vacuum plasma treatment, usually oxygen or argon plasma. It may also be an acidic or basic surface treatment and / or solvent treatment (water or organic solvent).

[0067] In the present application, the spectral reflectivity of the ophthalmic lens, for a given angle of incidence of the face comprising said filter, represents the variation of the reflectivity (i.e. of the reflection factor) at this angle of incidence as a function of the wavelength. The spectral reflectivity curve corresponds to a graphical representation of the spectral reflectivity in which the spectral reflectivity (ordinates) is plotted as a function of the wavelength (abscissas). The spectral reflectivity curves can be measured using a spectrophotometer, for example a Perkin Elmer Lambda 850 spectrophotometer equipped with URA (Universal Reflectance Accessory).

[0068] The average reflection factor, denoted R m , is as defined in ISO 13666:1998, and measured in accordance with ISO 8980-4 (at an angle of incidence less than 17°, typically 15°), i.e. it is the (unweighted) average of the spectral reflectivity over the entire light spectrum from 400 nm to 700 nm.

[0069] Similarly, the luminous reflectance factor, denoted R v , also referred to in this application as the average luminous reflectance factor, is as defined in ISO 13666:1998, and measured in accordance with ISO 8980-4 (at an angle of incidence of less than 17°, typically 15°), i.e. it is the weighted average of the spectral reflectivity over the entire visible light spectrum between 380 nm and 780 nm.

[0070] By analogy, we define an average reflection factor in the blue between 420 nm and 450 nm, noted R m,B , which corresponds to the average (unweighted) of the spectral reflectivity over the wavelength range from 420 nm to 450 nm.

[0071] According to the invention, this average reflection factor in the blue R m,B can be measured for an angle of incidence on the main face comprising the filter between 0° (normal incidence) and 15°, preferably at 15°.

[0072] In this application, it will also be noted: R θ (435 nm) the value of the reflectivity of the main face of the ophthalmic lens comprising the filter according to the invention, this value being determined (by measurement or by calculation) at a wavelength of 435 nanometers and for an angle of incidence θ on the main face comprising the filter of between 0° and 15°, and R θ' (435 nm) the value of the reflectivity of the main face of the ophthalmic lens comprising the filter according to the invention, this value being determined (by measurement or by calculation) at a wavelength of 435 nanometers and for an angle of incidence θ' on the main face comprising the filter of between 30° and 45°.

[0073] We will then define a parameter Δ(θ,θ') by the following relation: Δ(θ,θ') = 1 - [ R θ' (435 nm) / R θ (435 nm) ]. We will see in the rest of the description how this parameter Δ(θ,θ') makes it possible to evaluate the effectiveness of an ophthalmic lens in limiting the quantity of phototoxic blue light arriving on the retina of a wearer, taking into account the respective contributions of the blue light coming from the front side or from the back side of the lens.

[0074] According to the invention, the filter gives the main face of the ophthalmic lens comprising the filter the property of having, for an angle of incidence on this main face of between 0° and 15°, an average reflection factor in the blue R m,B which is greater than or equal to 5%.

[0075] The filter is thus specially designed to maximize the average reflection factor in the blue R m,B . This makes it possible to maximize the rejection of phototoxic blue light, in the wavelength range from 420 nm to 450 nm, arriving directly on the main front face of the lens. It is considered here that the majority of the direct light which comes from the front of the wearer of the ophthalmic lens and which reaches the wearer's retina has a low incidence on the main front face, generally between 0° and 15°.

[0076] According to a preferred embodiment of the invention, the average reflection factor in blue R m,B , for an angle of incidence on the main face of the ophthalmic lens comprising the filter of between 0° and 15°, preferably 15°, is greater than or equal to 10%, better still greater than or equal to 20%, and even better still greater than or equal to 30%, and optimally greater than or equal to 50%.

[0077] In accordance with the invention, the filter also gives the main face comprising the filter the property of presenting a spectral reflectivity curve for an angle of incidence on this main face of between 0° and 15°, preferably 15°, which has: a maximum reflectivity at a wavelength less than 435 nanometers, and a full width at half maximum (FWHM) greater than or equal to 80 nanometers.

[0078] Indeed, as can be seen on the figures 1 to 3 , the spectral reflectivity curves of the main front face of the ophthalmic lenses in accordance with the invention generally have, in the wavelength range from 380 nm to 500 nm, a “bell” shape which can be characterized by its height (maximum reflectivity) and its width at half-height (FWHM or “Full Width at Half Maximum " in English).

[0079] According to the invention, the maximum reflectivity is obtained for a wavelength less than 435 nm. It is therefore shifted relative to the central wavelength (435 nm) of the wavelength band between 420 nm and 450 nm of phototoxic blue light.

[0080] Preferably, the maximum reflectivity is at a wavelength less than or equal to 410 nm, better still less than or equal to 400 nm and even better still less than or equal to 390 nm.

[0081] In a preferred embodiment, this shift is limited such that the reflectivity maximum is also at a wavelength greater than or equal to 350 nm. Preferably, the reflectivity maximum is at a wavelength greater than 360 nm, more preferably greater than or equal to 370 nm.

[0082] According to the invention, the width at half-height of the spectral reflectivity curve considered, for an angle of incidence on the main face comprising the filter between 0° and 15° is greater than or equal to 80 nm.

[0083] A filter sized so that the spectral reflectivity curve for an angle of incidence on the main face comprising the filter between 0° and 15° has a full width at half maximum (FWHM) greater than or equal to 80 nanometers, will hereinafter be referred to as a wide filter.

[0084] In a preferred embodiment, the width at half maximum is greater than or equal to 90 nanometers, preferably greater than or equal to 100 nanometers.

[0085] Also preferably, the width at half maximum is less than 150 nanometers, more preferably less than 120 nanometers, more preferably less than 110 nm.

[0086] Still according to the invention, the filter finally gives the main face of the ophthalmic lens comprising the filter the property of having a parameter Δ(θ,θ'), as defined previously, greater than or equal to 0.6.

[0087] As defined previously, the parameter Δ(θ,θ') depends both on the reflectivity at 435 nm for an angle of incidence θ on the main face between 0° and 15°, noted R θ (435 nm) and on the reflectivity at 435 nm for an angle of incidence θ' on the main face between 30° and 45°, noted R θ' (435 nm).

[0088] In the case of an ophthalmic lens according to the invention, placed in front of the eye of a wearer, as explained in the introduction, it is understood that the quantity of phototoxic blue light included in the wavelength range from 420 nm to 450 nm arriving directly on the main front face of the ophthalmic lens and reaching the eye of the wearer varies in the inverse direction of the quantity R θ (435 nm).

[0089] Similarly, the amount of phototoxic blue light in the wavelength range 420 nm to 450 nm arriving indirectly from behind the wearer and reflected by the ophthalmic lens varies in the same direction as the quantity R θ' (435 nm).

[0090] Thus, by choosing a parameter Δ(θ,θ') such that Δ(θ,θ') ≥ 0.6, we obtain an ophthalmic lens with an effective and optimized filter against phototoxic blue light. Indeed, the parameter Δ(θ,θ') is all the higher as: (i) the value of the reflectivity R θ' (435 nm) is low, i.e. the amount of phototoxic blue light coming from the back of the wearer and reflected by the ophthalmic lens towards the wearer's retina is low, and (ii) the value of the reflectivity R θ (435 nm) is high, i.e. the amount of phototoxic blue light arriving directly on the front main face of the ophthalmic lens and reflected by it is high.

[0091] In a preferred embodiment, the parameter Δ(θ,θ') of the ophthalmic lens provided with a wide filter according to the invention is greater than or equal to 0.7, better still greater than or equal to 0.75, and even better still greater than or equal to 0.8.

[0092] Preferably, the parameter Δ(θ,θ') is determined for an angle of incidence θ substantially equal to 15° and an angle of incidence θ' substantially equal to 45°.

[0093] Preferably, the average transmission factor in the blue between 465 nm and 495 nm of the ophthalmic lens according to the invention (for an angle of incidence on the front main face of between 0° and 15°), which corresponds to the (unweighted) average of the spectral transmittance over the wavelength range from 465 nm to 495 nm, is greater than or equal to 80%, better still greater than or equal to 85%, and even better still greater than or equal to 90%.

[0094] This ensures that most of the blue light between 465 nm and 495 nm, which is responsible for synchronizing the biological clock, is transmitted to the eye of a wearer fitted with this ophthalmic lens.

[0095] Preferably, the transmission factor of the ophthalmic lens at 480 nm for an angle of incidence on the main front face of between 0° and 15° is greater than or equal to 70%, better still greater than or equal to 90%, and even better still greater than or equal to 95%.

[0096] In a preferred embodiment of the invention, the filter that the lens comprises is an interference filter. This means that the filter comprises at least one layer formed on one of the main faces of the ophthalmic lens provided with the interference filter, this layer having a refractive index different by at least 0.1 units from the refractive index of the substrate. The optical properties of such a filter, such as for example the reflectivity, result from interferences originating from multiple reflections at the air / layer and substrate / layer interfaces.

[0097] A filter layer is defined as having a deposited thickness greater than or equal to 1 nm. Therefore, any layer with a thickness less than 1 nm will not be counted in the number of filter layers. Any sub-layer placed between the filter and the substrate is also not counted in the number of layers of the interference filter.

[0098] Unless otherwise indicated, all layer thicknesses disclosed in this application are physical thicknesses, not optical thicknesses.

[0099] When the interference filter of the invention comprises at least two layers, it then comprises a stack of at least one layer of high refractive index, or “high index layer” designated HI layer, and at least one layer of low refractive index, or “low index layer” designated BI layer.

[0100] In a preferred embodiment, the interference filter comprises less than 11 layers, preferably a number of layers ranging from 2 to 10 layers, more preferably from 4 to 9 layers, optimally from 4 to 7 layers. It is not necessary for the HI and BI layers to be alternated in the stack of the interference filter, although they may be according to one embodiment of the invention. Two (or more) HI layers may be deposited one on top of the other, just as two (or more) BI layers may be deposited one on top of the other.

[0101] In the present application, a layer of the interference filter is called a "high refractive index layer" when its refractive index is greater than 1.60, preferably greater than or equal to 1.65, more preferably greater than or equal to 1.70, better still greater than or equal to 1.80 and even better still greater than or equal to 1.90. Similarly, a layer of the interference filter is called a low refractive index layer when its refractive index is less than 1.50, preferably less than or equal to 1.48, more preferably less than or equal to 1.47.

[0102] Unless otherwise indicated, the refractive indices referred to in this application are expressed at a temperature of 25°C and for a reference wavelength equal to 550 nm.

[0103] The HI layer is a conventional high refractive index layer well known in the art. It generally comprises one or more inorganic oxides such as, but not limited to: zirconia (ZrO 2 ), titanium oxide (TiO 2 ), alumina (Al 2 O 3 ), tantalum pentoxide (Ta 2 O 5 ), neodymium oxide (Nd 2 O 5 ), praseodymium oxide (Pr 2 O 3 ), praseodymium titanate (PrTiO 3 ), lanthanum oxide (La 2 O 3 ), niobium pentoxide (Nb 2 O 5 ), or yttrium oxide (Y 2 O 3 ). Optionally, the HI layers may also contain silica or other low refractive index materials, provided that their refractive index is greater than 1.60 as indicated above. Preferred materials are TiO 2 , PrTiO 3 , ZrO 2 , Al 2 O 3 , Y 2 O 3 and mixtures thereof.

[0104] The BI layer is also a well-known conventional low refractive index layer and may comprise, without limitation: silica (SiO 2 ), or a mixture of silica and alumina, in particular silica doped with alumina, the latter contributing to increasing the thermal resistance of the interference filter. The BI layer is preferably a layer comprising at least 80% by mass of silica, more preferably at least 90% by mass of silica, relative to the total mass of the BI layer, and even more preferably consists of a layer of silica.

[0105] Optionally, low-index layers may also contain high refractive index materials, provided that the refractive index of the resulting layer is less than 1.50.

[0106] When a BI layer comprising a mixture of SiO 2 and Al 2 O 3 is used, it preferably comprises from 1 to 10%, better still from 1 to 8% and even better still from 1 to 5% by mass of Al 2 O 3 relative to the total mass of silica and alumina in this layer.

[0107] For example, SiO 2 layers doped with 4% or less Al 2 O 3 by mass, or a SiO 2 layer doped with 8% Al 2 O 3 can be used. Commercially available SiO 2 / Al 2 O 3 mixtures can be used, such as LIMA ®< marketed by UMICORE MATERIALS AG (refractive index between 1.48 and 1.50), or the substance L5 ®< marketed by MERCK KGaA (refractive index equal to 1.48 at a wavelength of 500 nm).

[0108] The outer layer of the interference filter is generally a low index layer, typically silica-based, preferably comprising at least 80% by mass of silica, better still at least 90% by mass of silica (for example a layer of silica doped with alumina), relative to the total mass of this outer layer, and even better still consists of an outer layer of silica.

[0109] In a preferred embodiment, the filter has a total thickness of less than or equal to 700 nanometers, more preferably less than or equal to 600 nm. The total thickness of the filter is generally greater than 200 nm, preferably greater than 250 nm.

[0110] In particular embodiments of the invention where the filter is an interference filter comprising 8 or 9 layers, the total thickness of the stack is preferably between 450 nm and 600 nm.

[0111] In the particular embodiments of the invention where the filter is an interference filter comprising 6 or 7 layers, the total thickness of the stack is preferably less than 500 nm, better still it is between 300 nm and 500 nm.

[0112] In the particular embodiments of the invention where the filter is an interference filter comprising 4 or 5 layers, the total thickness of the stack is preferably less than 300 nm, better still it is between 200 nm and 300 nm.

[0113] Generally, HI layers have a physical thickness ranging from 10 nm to 100 nm, better less than or equal to 80 nm, and even better less than or equal to 70 nm, and BI layers have a physical thickness ranging from 10 nm to 150 nm, better less than or equal to 135 nm, and even better less than or equal to 120 nm.

[0114] The ophthalmic lens of the invention can also be made antistatic, i.e. not retain and / or develop an appreciable electrostatic charge, by incorporating at least one electrically conductive layer into the filter.

[0115] Preferably, it is an additional layer of a conductive oxide such as indium oxide, tin oxide, ITO (Indium Tin Oxide). This layer has a thickness generally less than 20 nm, preferably between 5 nm and 15 nm.

[0116] It is preferentially adjacent to a high index layer such as a zirconium oxide layer.

[0117] Preferably, this conductive layer is placed under the last low index layer of the filter (i.e. the layer closest to the air), generally silica-based.

[0118] According to one embodiment of the invention, the filter is deposited on a sub-layer. It is considered here that this sub-layer of the filter is not part of the filter.

[0119] Filter undercoat, or adhesion layer, means a coating of relatively significant thickness, used for the purpose of improving mechanical properties such as abrasion and / or scratch resistance of the filter and / or promoting its adhesion to the underlying substrate or coating.

[0120] Given its relatively large thickness, the undercoat does not generally participate in the optical filtering activity of the filter, in particular in the case where it has a refractive index close to that of the underlying coating (which is generally the anti-abrasion and / or anti-scratch coating) or that of the substrate of the ophthalmic lens, when the undercoat is directly deposited on the substrate of the ophthalmic lens.

[0121] The undercoat should be of sufficient thickness to promote the abrasion resistance of the filter, but preferably not so thick as to cause light absorption which, depending on the nature of the undercoat, could significantly reduce the visual transmittance T v as defined in ISO 13666:1998, and measured in accordance with ISO 8980-3.

[0122] The thickness of this sub-layer is generally less than 300 nm, better less than 200 nm, and is generally greater than 90 nm, better greater than 100 nm.

[0123] The underlayer preferably comprises a SiO 2 -based layer, preferably comprising at least 80% by mass of silica, better still at least 90% by mass of silica, relative to the total mass of the underlayer, and even better still consists of a silica underlayer. The thickness of this silica-based underlayer is generally less than 300 nm, better still less than 200 nm, and is generally greater than 90 nm, better still greater than 100 nm.

[0124] According to another embodiment, this SiO 2 -based sub-layer is a silica sub-layer doped with alumina, in proportions as defined above, preferably consisting of a silica layer doped with alumina.

[0125] According to a particular embodiment, the underlayer consists of a layer of SiO 2 .

[0126] It is preferable to use a single-layer undercoat. However, the undercoat may be laminated (multi-layered), particularly when the undercoat and the underlying coating (or the substrate, if the undercoat is deposited directly on the substrate) have a significant difference in refractive index. This is particularly the case when the underlying coating, which is generally an abrasion-resistant and / or scratch-resistant coating, or the substrate, have a high refractive index, by which term is meant a refractive index greater than or equal to 1.55, preferably greater than or equal to 1.57.

[0127] In this case, the underlayer may comprise, in addition to a layer with a thickness of between 90 nm and 300 nm, called the main layer, preferably at most three other layers, better still at most two other layers, intercalated between the possibly coated substrate and this layer with a thickness of between 90 nm and 300 nm, which is generally a silica-based layer. These additional layers are preferably thin layers, the function of which is to limit multiple reflections at the underlayer / underlying coating interface or at the underlayer / substrate interface, as the case may be.

[0128] A multi-layer sub-layer preferably comprises, in addition to the main layer, a layer with a high refractive index and a thickness less than or equal to 80 nm, better still less than or equal to 50 nm and even better still less than or equal to 30 nm. This high refractive index layer is directly in contact with the high refractive index substrate or the underlying high refractive index coating, as the case may be. Of course, this embodiment can be used even if the substrate (or the underlying coating) has a refractive index less than 1.55.

[0129] Alternatively, the underlayer comprises, in addition to the main layer and the aforementioned high refractive index layer, a layer of material with a refractive index of less than or equal to 1.55, preferably less than or equal to 1.52, better still less than or equal to 1.50 based on SiO 2 (i.e. preferably comprising at least 80% by mass of silica) with a thickness of less than or equal to 80 nm, better still less than or equal to 50 nm and even better still less than or equal to 30 nm, on which said high refractive index layer is deposited. Typically, in this case, the underlayer comprises, deposited in this order on the optionally coated substrate, a 25 nm layer of SiO 2 , a 10 nm layer of ZrO 2 or Ta 2 O 5 and the main layer of the underlayer.

[0130] The filter and any undercoat are preferably deposited by vacuum deposition using one of the following techniques: i) by evaporation, possibly assisted by ion beam; ii) by ion beam sputtering; iii) by cathode sputtering; iv) by plasma-assisted chemical vapor deposition. These different techniques are described in the works " Thin Film Processes " And " Thin Film Processes II" (Vossen & Kern Editors, Academic Press, 1978 and 1991 respectively). A particularly recommended technique is vacuum evaporation.

[0131] Preferably, when the filter is an interference filter, the deposition of each of the layers of the filter stack and of the possible sub-layer is carried out by vacuum evaporation.

[0132] In a particular embodiment of the invention, the ophthalmic lens has an average light reflection factor R v on the main face of the ophthalmic lens comprising the filter which is less than or equal to 2.5%. Preferably, this average light reflection factor R v is less than or equal to 2%, better still less than or equal to 1.5%. In a particularly preferred embodiment, the average light reflection factor R v is less than or equal to 0.7%, better still less than or equal to 0.6%.

[0133] In a preferred embodiment, the ophthalmic lens has an average light reflection factor R v on each of the main faces of the ophthalmic lens which is less than or equal to 2.5%. Better still, this average light reflection factor R v is less than or equal to 0.7%.

[0134] According to a preferred embodiment of the invention, the main face coated by the filter according to the invention is the front main face of the ophthalmic lens of the invention and the rear main face is coated with a conventional anti-reflective coating or preferably with an anti-reflective coating effective in the UV, that is to say reflecting little UV, such as those described for example in document PCT / EP2011 / 072386.

[0135] The average reflection factor in the UV R UV on the main rear face of the ophthalmic lens, for wavelengths between 280 nm and 380 nm, weighted by the function W(λ) defined in the ISO 13666:1998 standard, is less than or equal to 7%, better still less than or equal to 6%, and even better still less than or equal to 5%, for an angle of incidence of 30° and for an angle of incidence of 45°. The average reflection factor in the UV R UV is defined by the relationship: R UV = ∫ 280 380 W λ . R λ . dλ ∫ 280 380 W λ . dλ where R(λ) denotes the spectral reflectivity on the main rear face of the ophthalmic lens at the wavelength considered, and W(λ) denotes a weighting function equal to the product of the solar spectral irradiance Es(λ) by the relative spectral efficiency function S(λ).

[0136] The spectral function W(λ), which allows the calculation of UV radiation transmission factors, is defined in the ISO 13666:1998 standard.

[0137] The UV-effective antireflective coating preferably comprises a stack of at least one high refractive index layer and at least one low refractive index layer.

[0138] In another embodiment of the invention, the two main front and rear faces each comprise a filter against phototoxic blue light. The two filters thus formed, one on the main front face and the other on the main rear face, can then be identical or different.

[0139] The filter according to the invention can be deposited directly on a bare substrate. In certain applications, it is preferable for the main face of the ophthalmic lens comprising the filter to be coated with one or more functional coatings prior to the formation of the filter on this main face. These functional coatings, conventionally used in optics, can be, without limitation: an anti-shock primer layer, an anti-abrasion and / or anti-scratch coating, a polarizing coating, a colored coating.

[0140] Generally, the main front and / or back face of the substrate on which a filter will be formed is coated with a layer of shock-resistant primer, an anti-abrasion and / or anti-scratch coating.

[0141] The filter is preferably deposited on an anti-abrasion and / or anti-scratch coating. The anti-abrasion and / or anti-scratch coating may be any layer conventionally used as an anti-abrasion and / or anti-scratch coating in the field of ophthalmic lenses. Such coatings are described, among others, in document EP 0614957.

[0142] The ophthalmic lens according to the invention may also comprise coatings formed on the filter and capable of modifying its surface properties, such as hydrophobic and / or oleophobic coatings (“ top coat »anti-fouling) and / or anti-fog coatings. Such coatings are described, among others, in document US 7678464. These coatings are preferably deposited on the outer layer of the filter. Their thickness is generally less than or equal to 10 nm, preferably from 1 nm to 10 nm, better still from 1 nm to 5 nm.

[0143] Typically, an ophthalmic lens according to the invention comprises a substrate successively coated on its main front face with an anti-shock primer layer, an anti-abrasion and / or anti-scratch layer, a filter according to the invention, and a hydrophobic and / or oleophobic coating.

[0144] The ophthalmic lens according to the invention is preferably an ophthalmic lens for spectacles, or an ophthalmic lens blank. The invention thus also relates to a pair of spectacles comprising at least one such ophthalmic lens.

[0145] The ophthalmic lens can be a polarized lens, or a solar lens, tinted, with or without correction.

[0146] The main rear face of the substrate of the optical article may be coated successively with a layer of shock-resistant primer, an anti-abrasion and / or anti-scratch layer, an anti-reflective coating which may or may not be an anti-UV anti-reflective coating, and a hydrophobic and / or oleophobic coating.

[0147] It is particularly advantageous for protecting the eye of a wearer suffering from eye deterioration, particularly due to a degenerative process such as age-related macular degeneration, from blue light phototoxicity.

[0148] An ophthalmic lens as described above also has the advantage of providing better visual contrast to the wearer.

[0149] The following examples illustrate the invention in more detail but are not limiting. EXAMPLES 1. General procedures and operating methods

[0150] The filters according to the invention are deposited on ORMA ® glasses coated with an anti-abrasion coating as described in example 3 of patent EP614957.

[0151] The evaporation device and the conditions for deposition of the SiO 2 and ZrO 2 layers (evaporation rate, pressure) are as described in patent application WO 2008107325. 2. Calculation of curves

[0152] The spectral reflectivity curves of the filters according to the invention were modeled using the software Essential Mac Leod (version 9.4) from Thin Film Center.

[0153] The characteristics of the filters and their properties are given in point 3 below.

[0154] The ophthalmic lenses equipped with the filters of examples 1 and 2 were actually produced and the spectral reflectivity curves measured.

[0155] It was verified that the curves obtained corresponded to those modeled. 3. Filter stacks and properties. Spectral reflectivity curves. Results

[0156] The structural characteristics and optical performances of the ophthalmic lenses obtained according to examples 1 to 3 are detailed in the table below (see next page).

[0157] The spectral reflectivity curves at an angle of incidence on the front main face of 15° and for wavelengths ranging from 280 nm to 780 nm of examples 1 to 3 below are shown in figures 1 to 3 . Also shown in these figures are the spectral reflectivity curves of comparative examples C1, C2, and C3 (see below).

[0158] The values ​​of the average reflection factors are those of the main front face. The factors R m, B and R v are indicated for an angle of incidence of 15°.

[0159] In the following table, the parameter Spectral Δ @ 15° is defined by the relation: Spectral Δ @ 15° = [ R 15° (435 nm) - R 15° (480 nm) ] / R 15° (435 nm) where R 15° (435 nm) and R 15° (480 nm) represent the reflectivity of the main front face at 435 nm and 480 nm respectively, for an angle of incidence of 15° on the main front face.

[0160] It is found that the ophthalmic lenses according to the invention have very good phototoxic blue light reflection properties (R m,B > 10%), without this harming the anti-reflection performance in the visible range (R v < 2.5% for an angle of incidence of 15°).

[0161] The ophthalmic lenses obtained according to Examples 1 to 3 also have excellent transparency properties and good colorimetric neutrality, good abrasion and scratch resistance, and good resistance to hot water dipping treatment followed by mechanical surface stress. The adhesion of the coatings to the substrate is also very satisfactory. Ex. 1: 4-layer wide filter on the main front face Ex. 2: 6-layer wide filter on the main front face Ex. 3: 8-layer wide filter on the main front face Substrate + hard coat Substrate + hard coat Substrate + hard coat ZrO2 34 nm ZrO2 44 nm ZrO2 47 nm SiO2 35 nm SiO2 45 nm SiO2 50 nm ZrO2 73 nm ZrO2 68 nm ZrO2 54 nm SiO2 110 nm SiO2 32 nm SiO2 70 nm Air ZrO2 66 nm ZrO2 45 nm SiO2 124 nm SiO2 62 nm Air ZrO2 53 nm SiO2 134 nm Air Total thickness 252 nm Total thickness 379 nm Total thickness 515 nm Rm,B @ 15° (420 - 450nm) 11,8% Rm,B @ 15° (420 - 450nm) 30,6% Rm,B @ 15° (420 - 450nm) 51,5% Max. Reflectivity 359 nm Max. Reflectivity 379 nm Max. Reflectivity 384 nm Width at half height 98 nm width at half height 100 nm width at half height 105 nm Δ(θ=15°,θ'=45°) @ 435 nm 0,72 Δ(θ=15°,θ'=45°) @ 435 nm 0,75 Δ(θ=15°,θ'=45°) @ 435 nm 0,80 Rm @ 15° (465 - 495 nm) 2,3% Rm @ 15° (465 - 495 nm) 4,5% Rm @ 15° (465 - 495 nm) 7,3% Spectral Δ @ 15° 435 nm / 480 nm 0,85 Spectral Δ @ 15° 435 nm / 480 nm 0,92 Spectral Δ @ 15° 435 nm / 480 nm 0,95 Rv @ 15° (380 - 780 nm) 0,5% Rv @ 15° (380 - 780 nm) 1,9% Rv @ 15° (380 - 780 nm) 2,0% Comparative examples C1, C2, and C3

[0162] The “anti-blue light” performances of three ophthalmic lenses equipped with a filter which does not satisfy the characteristics of the filters of the invention, in particular the width at mid-height, are recorded in the tables below (see next page).

[0163] It is found that the ophthalmic lenses equipped with filters according to the invention have a better light reflection factor R v than the comparative lenses, in particular the filters having a limited number of layers (number of layers less than or equal to 7, preferably less than or equal to 6 layers).

[0164] It is noted that all the ophthalmic lenses of comparative examples C1, C2, and C3 which are equipped with filters which do not satisfy the characteristics of the filters of the invention, in particular the width at half-height, have an average reflection factor in the blue R m,B greater than or equal to 5%.

[0165] On the other hand, as can be seen on the figures 1 to 3 , no comparative example of these ophthalmic lenses presents: a maximum reflectivity at a wavelength less than 435 nm, and a full width at half maximum greater than or equal to 80 nm. Comparative example C1: filter « narrow » 4-layer on the front main face Comparative example C2: 6-layer “narrow” filter on the main front face Comparative example C3: 8-layer “narrow” filter on the main front face Substrate + hard coat Substrate + hard coat Substrate + hard coat ZrO2 45 nm ZrO2 34 nm ZrO2 163 nm SiO2 15 nm SiO2 43 nm SiO2 220 nm ZrO2 235 nm ZrO2 315 nm ZrO2 182 nm SiO2 98 nm SiO2 25 nm SiO2 51 nm Air ZrO2 196 nm ZrO2 47 nm SiO2 115 nm SiO2 26 nm Air ZrO2 121 nm SiO2 107 nm Air Total thickness 393 nm Total thickness 728 nm Total thickness 917 nm Rm,B @ 15° (420 - 450nm) 8,5% Rm,B @ 15° (420 - 450nm) 35,0% Rm,B @ 15° (420 - 450nm) 55,0% Max. Reflectivity 435 nm Max. Reflectivity 437 nm Max. Reflectivity 436 nm width at half height 62 nm width at half height 47 nm width at half height 54 nm Δ(θ=0°,θ'=45°) @ 435 nm 0,40 Δ(θ=0°,θ'=45°) @ 435 nm 0,55 Δ(θ=0°,θ'=45°) @ 435 nm 0,57 Rm @ 15° (465 - 495 nm) 3,5% Rm @ 15° (465 - 495 nm) 7,5% Rm @ 15° (465 - 495 nm) 13,8% Spectral Δ @ 15° 435 nm / 480 nm 0,40 Spectral Δ @ 15° 435 nm / 480 nm 0,90 Spectral Δ @ 15° 435 nm / 480 nm 0,93 Rv @ 15° (380 - 780 nm) 1,4% Rv @ 15° (380 - 780 nm) 2,6% Rv @ 15° (380 - 780 nm) 2,1%

[0166] Furthermore, it will be understood in the light of the figure 4 the effectiveness of examples 1 to 3 of ophthalmic lenses according to the invention compared to comparative examples C1, C2, and C3 described above.

[0167] Backward thinking BR (λ) and transmission T(λ) of the entire optical system (with the blue filter corresponding to examples 1, 2 and 3 and to comparative examples C1, C2 and C3, on the front face of a biplane type lens made of ORMA ®< glass, bearing a Crizal Forte ®< UV antireflection coating on the rear face (R v = 0.59%, R UV = 3.1% for an incidence of 45°), were determined using the software Essential Mac Leod for each of the filters studied.

[0168] The calculation takes into account all the multiple reflections occurring within the ophthalmic lens.

[0169] To assess the risk associated with blue light, these transmission and reflection curves are weighted using the WB spectral function (λ) from the international standard ISO 8980-3. This function results from the product of the blue light risk function ( “blue-light hazard function” in English) B(λ) and the spectral distribution function of the sun ( “spectral distribution of solar radiation”in English) ES (λ) integrated over the wavelength range from 380 nm to 500 nm (see Table 1 on the next page).

[0170] On the figure 4 , are represented: on the abscissa: the value of the rear reflection weighted by the blue light risk weighting function, for an angle of incidence on the rear main face of 45°. BR B = ∫ 380 500 W B λ . BR λ . dλ ∫ 380 500 W B λ . dλ Or BR( λ ) is the back reflection spectral factor of the glass (“ back reflectance » in English), and on the ordinate: the transmission value weighted by the blue light risk weighting function. This transmission value represents the share (in %) of direct light transmitted in the blue-violet band (from 380 nm to 500 nm) by this ophthalmic lens for an angle of incidence on the main front face of 0°. T B = ∫ 380 500 W B λ . T λ . dλ ∫ 380 500 W B λ . dλ Or T(λ) is the spectral transmittance of the glass.

[0171] Greatness WB ( λ ) represents the weighting function which is equal to the product of the spectral solar irradiation Es( λ ) and the risk function of blue light B( λ ) (see table 1).

[0172] We see on the figure 4 that examples 1 to 3 of ophthalmic lenses according to the invention have not only lower transmission, but also lower rear reflection, than comparative examples C1, C2, and C3, with the same number of layers.

[0173] Thus, the ophthalmic lenses according to the invention make it possible to prevent a degenerative process of the eye of a wearer due to the phototoxicity of blue light, such as age-related macular degeneration.

[0174] Spectral functions for calculating transmission or reflection values ​​of light in the 380-500 nm band: Table 1 : λ Numerical data for calculating the weighting function WB(). Wavelength λ (nm) Spectral solar irradiation Es(λ) (mW / m 2< .nm) Blue light hazard function B(λ) Weighting function WB (λ) = Es(λ).B(λ) 380 336 0.006 2 385 365 0,012 4 390 397 0,025 10 395 432 0,05 22 400 470 0,10 47 405 562 0,20 112 410 672 0,40 269 415 705 0,80 564 420 733 0,90 660 425 760 0,95 722 430 787 0,98 771 435 849 1,00 849 440 911 1,00 911 445 959 0,97 930 450 1006 0,94 946 455 1037 0,90 933 460 1080 0,80 864 465 1109 0,70 776 470 1138 0,62 706 475 1161 0,55 639 480 1183 0,45 532 485 1197 0,40 479 490 1210 0,22 266 495 1213 0,16 194 500 1215 0,10 122

[0175] There Figure 5 represents the spectral reflectivity curves between 380 nm and 500 nm of the ophthalmic lens of example 3 for angles of incidence on the front main face of 0° and 45°.

[0176] We notice in this figure that the spectral reflectivity curve at 45° is shifted towards short wavelengths ( ie . towards deep blue and UV) compared to the spectral reflectivity curve at 0°. This illustrates the high angular selectivity of the wide filter in Example 3.

[0177] This shift then results in the value of the spectral reflectivity at 435nm for an angle of incidence of 45°, noted here R 45° (435 nm) being low, here equal to 11%, and much lower than the value of the spectral reflectivity at 435nm for an angle of incidence of 0°, noted here R 0° (435 nm), equal to 59.5%.

[0178] We therefore understand that the value of the parameter Δ(θ,θ') is high here, equal to 0.82. This is true for all ophthalmic lenses, which are equipped with at least one wide filter according to the invention.

[0179] On the contrary, and as can be seen from the tables of comparative examples, an ophthalmic lens equipped with a filter which does not satisfy the characteristics of the filters of the invention, in particular the width at half-height, does not have a parameter Δ(θ,θ') which is sufficiently high to be effective against phototoxic blue light.

Claims

1. An ophthalmic lens having a front main face and a back main face, at least one of both main faces comprising a filter, which provides the main face comprising said filter with the following properties: - an average blue reflectance factor (Rm,B) within a wavelength range of from 420 nanometers to 450 nanometers, which is higher than or equal to 5%, for an angle of incidence ranging from 0° to 15°, - a spectral reflectivity curve for an angle of incidence ranging from 0° to 15°, this reflectivity curve having: - a maximum reflectivity at a wavelength of less than 435 nanometers, and - a full width at half maximum (FWHM) higher than or equal to 80 nanometers, characterized in that - the reflectivity value at the maximum level of reflectivity of the main face comprising said filter, for an angle of incidence of 15°, is at least 1.5 times higher than the reflectivity value of the same main face, at a wavelength of 435 nm and for an angle of incidence of 15°, and - for an angle of incidence θ ranging from 0° to 15° and for an angle of incidence θ' ranging from 30° to 45°, a parameter Δ(θ,θ') defined by the relation Δ(θ,θ') = 1 - [ Rθ'(435 nm) / Rθ(435 nm)], in such a way that this parameter Δ(θ,θ') is higher than or equal to 0.6, where - Rθ(435 nm) represents the reflectivity value of the main face comprising said filter at a 435 nanometer-wavelength for the angle of incidence θ, and - Rθ'(435 nm) represents the reflectivity value of the main face comprising said filter at a 435 nanometer-wavelength for the angle of incidence θ'.

2. An ophthalmic lens according to claim 1, wherein the parameter Δ(θ,θ') is defined for an angle of incidence θ = 15° and for an angle of incidence θ' = 45°.

3. An ophthalmic lens according to claim 1 or 2, wherein the average blue reflectance factor (Rm,B) is higher than or equal to 10%, more preferably higher than or equal to 20%, and even more preferably higher than or equal to 30% for an angle of incidence ranging from 0° to 15°.

4. An ophthalmic lens according to any one of claims 1 to 3, wherein the maximum reflectivity is observed at a wavelength lower than or equal to 410 nm, more preferably lower than or equal to 400 nm, and even more preferably lower than or equal to 390 nm.

5. An ophthalmic lens according to any one of claims 1 to 4, wherein the maximum reflectivity is observed at a wavelength higher than or equal to 350 nm, more preferably higher than or equal to 360 nm.

6. An ophthalmic lens according to any one of claims 1 to 5, wherein the full width at half maximum is higher than or equal to 90 nanometers, preferably higher than or equal to 100 nanometers.

7. An ophthalmic lens according to any one of claims 1 to 6, wherein the full width at half maximum is lower than or equal to 150 nanometers, preferably lower than or equal to 120 nanometers, more preferably lower than or equal to 110 nm.

8. An ophthalmic lens according to any one of claims 1 to 7, wherein the average luminous reflectance factor (Rv) on the main face of the ophthalmic lens comprising the filter is lower than or equal to 2.5%, preferably lower than or equal to 1.5%.

9. An ophthalmic lens according to any one of claims 1 to 7, wherein the average luminous reflectance factor (Rv) on each of the main faces of the ophthalmic lens is lower than or equal to 2.5%, preferably lower than or equal to 1.5%.

10. An ophthalmic lens according to any one of claims 1 to 9, wherein the filter is an interference filter.

11. An ophthalmic lens according to claim 10, wherein the filter comprises a number of layers lower than or equal to 11, preferably ranging from 2 to 10 layers, and more preferably from 4 to 9 layers.

12. An ophthalmic lens according to any one of claims 1 to 11, wherein the filter has a total thickness lower than or equal to 700 nanometers, preferably lower than or equal to 600 nanometers.

13. An ophthalmic lens according to any one of claims 1 to 12, characterized in that the ratio [ R15°(435 nm) - R15°(480 nm) ] / R15°(435 nm) is higher than or equal to 0.8, where R15°(435 nm) and R15°(480 nm) represent respectively the reflectivity of the main face comprising said filter at 435 nm and at 480 nm, for an angle of incidence of 15° on this main face.

14. An ophthalmic lens according to any one of claims 1 to 13, characterized in that the reflectivity value at the maximum level of reflectivity of the main face comprising said filter, for an angle of incidence of 15°, is at least 2 times higher than the reflectivity value of the same main face, at a wavelength of 435 nm and for an angle of incidence of 15°.

15. An ophthalmic lens according to any one of claims 1 to 14, wherein the filter is formed on the front main face of the ophthalmic lens.

16. An ophthalmic lens according to claim 15, wherein the back main face of the ophthalmic lens comprises an antireflection coating efficient within the UV region having an average reflectance factor within the UV region RUV on the back main face of the ophthalmic lens, for wavelengths ranging from 280 nm to 380 nm, weighted by the function W(λ) defined in the standard ISO 13666:1998, lower than or equal to 7%, for an angle of incidence of 30° and for an angle of incidence of 45°, the average reflectance factor within the UV region RUV being defined by the relation: R UV = ∫ 280 380 W λ . R λ . dλ ∫ 280 380 W λ . dλ wherein R(λ) represents the spectral reflectivity on the back main face of the ophthalmic lens at the relevant wavelength, and W(λ) represents a weighting function that is equal to the product of solar spectral irradiance Es(λ) and relative spectral efficiency function S(λ).

17. An ophthalmic lens having a front main face and a back main face, at least one of both main faces comprising a filter, which provides the main face comprising said filter with the following properties: - an average blue reflectance factor (Rm,B) within a wavelength range of from 420 nanometers to 450 nanometers, which is higher than or equal to 10%, preferably higher than or equal to 20%, more preferably higher than or equal to 30%, for an angle of incidence ranging from 0° to 15°, - a spectral reflectivity curve for an angle of incidence ranging from 0° to 15°, this reflectivity curve having: - a maximum reflectivity at a wavelength of less than 435 nanometers, and - a full width at half maximum (FWHM) higher than or equal to 70 nanometers, preferably higher than or equal to 75 nm, and characterized in that - for an angle of incidence θ ranging from 0° to 15° and for an angle of incidence θ' ranging from 30° to 45°, a parameter Δ(θ,θ') defined by the relation Δ(θ,θ') = 1 - [ Rθ'(435 nm) / Rθ(435 nm)], in such a way that this parameter Δ(θ,θ') is higher than or equal to 0.5, where - Rθ(435 nm) represents the reflectivity value of the main face comprising said filter at a 435 nanometer-wavelength for the angle of incidence θ, and - Rθ'(435 nm) represents the reflectivity value of the main face comprising said filter at a 435 nanometer-wavelength for the angle of incidence θ' and - for an angle of incidence ranging from 0° to 15°, a parameter Δspectral defined by the relation Δspectral = 1 - [ R0°-15°(480 nm) / R0°-15°(435 nm)], in such a way that this parameter Δspectral is higher than or equal to 0.8, where - R0°-15°(480 nm) represents the reflectivity value of the front main face at a 480 nanometer-wavelength for the relevant incidence, and - R0°-15°(435 nm) represents the reflectivity value of the front main face at a 435 nanometer-wavelength for the relevant incidence.

18. An ophthalmic lens according to claim 17, wherein the parameter Δ(θ,θ') is defined for an angle of incidence θ = 15° and an angle of incidence θ' = 45°.

19. An ophthalmic lens according to claim 17, wherein the parameter Δspectral is defined for an angle of incidence of 15°.

20. An ophthalmic lens according to any one of claims 17 to 19, wherein the maximum reflectivity is observed at a wavelength higher than or equal to 350 nm, more preferably higher than or equal to 360 nm.

21. An ophthalmic lens according to any one of claims 17 to 20, wherein the full width at half maximum is lower than or equal to 150 nanometers, preferably lower than or equal to 120 nanometers, more preferably lower than or equal to 110 nm.