EP3329325A1

EP3329325A1 - Ophthalmic lens and associated production method

Info

Publication number: EP3329325A1
Application number: EP16758230.3A
Authority: EP
Inventors: Christelle Marck; Abigaëlle CABARET
Original assignee: Essilor International Compagnie Generale dOptique SA
Current assignee: EssilorLuxottica SA
Priority date: 2015-07-28
Filing date: 2016-07-27
Publication date: 2018-06-06
Also published as: US20180224575A1; WO2017017374A1; FR3039659B1; FR3039659A1; CN107924070A

Abstract

The invention concerns an ophthalmic lens (1) that comprises a substrate (2) having a front main face (3) and a rear main face (4) and a photonic crystal layer (5) at least partially covering one of said main faces, and that has a spectral reflectivity curve for an incident angle on the front main face of between 0° and 45°, having a reflectivity peak with a maximum reflectivity value at a peak wavelength of between 420 and 450 nanometres, and a chroma value on reflection by the front main face with an incident angle of between 0° and 45° that is less than 30. The invention also concerns a method for producing such an ophthalmic lens.

Description

Ophthalmic lens and method of manufacturing

TECHNICAL FIELD TO WHICH THE INVENTION REFERS

The invention relates generally to the field of ophthalmic optics.

It relates more particularly to an ophthalmic lens designed to reduce the effects of the phototoxicity of blue light on the retina of an eyeglass wearer.

It also relates to a method of manufacturing such an ophthalmic lens.

ARRI TECHNOLOGICAL BACKGROUND

The light visible by the human eye extends over a light spectrum ranging from a wavelength of 380 nanometers (nm) to about 780 nm. The part of this spectrum, located between about 380 nm and 500 nm, corresponds to a substantially blue, high energy light.

Many studies (see 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, especially the retina.

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 Too long or too intense blue light exposure can induce severe ophthalmic conditions such as age-related macular degeneration (AMD).

Nevertheless, a part of this blue light, between about 465 nm and 495 nm is beneficial insofar as it intervenes in the mechanisms of regulation of biological rhythms, called "circadian cycles".

Thus, it is recommended to limit the exposure to potentially harmful blue light, especially for the wavelength band which presents an increased dangerousness (see in particular table B1 of the standard ISO 8980-3: 2003 (E) concerning the danger function of the blue light).

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

It has been proposed in WO 2013/084177 an ophthalmic lens comprising a substrate having a front main face and a rear main face, and a selective interference filter, for example a photonic crystal layer,

The ophthalmic lenses of WO 2013/084177 reflect phototoxic blue light over a wide range of wavelengths, for example from 395 nm to 465 nm. The reflection of the surrounding light on the main front side of the substrate of the lens can then cause a marked bluish reflection.

In some cases, this aesthetic defect may cause the wearer to reject such ophthalmic lenses.

It is therefore desirable to provide ophthalmic lenses to attenuate the blue light transmission without creating unsightly reflection.

OBJECT OF THE INVENTION

In order to overcome the aforementioned disadvantage of the state of the art, the present invention proposes an ophthalmic lens that not only limits the amount of phototoxic blue light reaching the retina of the wearer, but also reduces the residual hue in the eye. reflection of such an ophthalmic lens.

More particularly, there is provided according to the invention an ophthalmic lens comprising: a substrate having a front main face and a rear main face, and a photonic crystal layer covering at least part of one of said main faces of the substrate,

said ophthalmic lens having:

a spectral reflectivity curve for an angle of incidence on said front main face between 0 ° and 45 ° which compréid a reflectivity peak having a maximum value of reflectivity at a peak wavelength between 420 and 450 nanometers, and a chroma value in reflection on said front main face with an angle of incidence between 0 ° and 45 ° which is less than 30.

Thanks to the value of chroma in reflection which is limited to 30, the ophthalmic lens of the invention has a residual light in low intensity reflection, so that an observer of the wearer of this ophthalmic lens does not perceive or not the bluish reflection on the front main face of the substrate.

In addition, the wearer of this lens is correctly protected from the phototoxic effects of blue light between 400 and 460 nm thanks to the peak of reflectivity which is maximum in this range of wavelengths.

Other nonlimiting and advantageous features of the ophthalmic lens according to the invention, taken individually or in any technically possible combination, are as follows:

the ophthalmic lens has, in transmission through said ophthalmic lens with an angle of incidence between 0 ° and 45 °, a yellow index of less than 30;

said maximum reflectivity value is greater than 15%;

said peak of reflectivity has a width at half height less than 80 nanometers;

said chroma value is less than 20;

said ophthalmic lens has, for an angle of incidence between 0 ° and 45 °, a mean transmission factor in blue over a range of wavelengths ranging from 420 to 450 nanometers, less than 80%;

said ophthalmic lens has a mean transmittance of greater than 92%;

said ophthalmic lens has a mean light reflection factor of less than 2.5%;

said photonic crystal layer is formed of a matrix and colloidal particles arranged in said matrix;

said photonic crystal layer has a thickness of between 1 and 40 micrometers, preferably between 3 and 30 micrometers.

said photonic crystal layer has a spectral reflectivity curve for an angle of incidence between 0 ° and 45 ° which includes a reflectivity peak having a maximum reflectivity value at a wavelength of between 420 and 450 nanometers, and a chroma value in reflection on said layer with an angle of incidence between 0 ° and 45 ° which is less than 30.

The photonic crystal layer may be deposited in different ways on the substrate of the ophthalmic lens.

The invention thus proposes a method of manufacturing an ophthalmic lens according to the invention.

According to a first aspect, the manufacturing method comprises the following steps: a) depositing on an plastic film an initial layer of a solution containing a solvent and a composition containing colloidal particles suspended in a matrix;

b) evaporating at least a portion of the solvent from the initial layer deposited on said plastic film so that the colloidal particles arrange in said matrix to form a photonic crystal interlayer on said plastic film;

c) solidifying the matrix of said intermediate layer on said plastic film to form a photonic crystal layer on said plastic film; and

d) applying said plastic film to said ophthalmic lens so as to secure said photonic crystal layer on at least one of the front and back main faces of a substrate of the ophthalmic lens.

According to the invention, the composition used in step a) of the method is adapted so that the ophthalmic lens has:

a spectral reflectivity curve for an angle of incidence on said front main face between 0 ° and 45 ° which compréid a reflectivity peak having a maximum value of reflectivity at a peak wavelength between 420 and 450 nanometers, and a chroma value in reflection on said front main face with an angle of incidence between 0 ° and 45 ° which is less than 30. According to a second aspect, the manufacturing method comprises the following steps: a ') depositing an initial layer of a solution containing a solvent and a composition containing colloidal particles suspended in a matrix on at least one of the main faces before and back of a substrate of the ophthalmic lens;

b ') evaporating at least part of the solvent of the initial layer deposited on said main face so that the colloidal particles arrange in said matrix to form a photonic crystal interlayer; and

c ') solidifying the matrix of the intermediate layer.

According to the invention, the composition used in step a) is adapted so that the ophthalmic lens has:

DETAILED DESCRIPTION OF AN EXEMPLARY EMBODIMENT

The following description with reference to the accompanying drawings, given as non-limiting examples, will make it clear what the invention consists of and how it can be achieved.

In the accompanying drawings:

FIG. 1 is a schematic view of an ophthalmic lens according to the invention comprising a photonic crystal layer on the front face and an antireflection treatment on the rear face;

Figure 2 is an exploded view of the ophthalmic lens of the figurel;

FIG. 3 is a detailed view of the ophthalmic lens of FIG. 1 showing the structure of the photonic crystal layer;

Figure 4 is a schematic view of a core-bark type colloidal particle entering the composition of the photonic crystal layer of Figure 3;

FIG. 5 represents the spectral reflectivity curves for an ophthalmic lens of the prior art and an ophthalmic lens according to the invention;

FIG. 6 represents the spectral transmission curves of an ophthalmic lens according to the invention for different thicknesses of the photonic crystal layer.

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

In known manner, and as shown in Figures 1 and 2, the ophthalmic lens 1 according to the invention comprises a transparent substrate 2 of mineral or organic glass. This substrate may comprise one or more functional coatings for imparting to the ophthalmic lens particular optical and / or mechanical properties, such as, for example, an anti-shock coating, an anti-abrasion coating, an adhesive coating, a barrier coating, a anti-reflective coating, anti-UV coating, anti-static coating, polarizing coating, tinting coating and antifouling and / or anti-fogging coating.

The substrate 2 of the ophthalmic lens 1 is preferably made of organic glass, for example a thermoplastic or thermosetting plastic material.

Among the thermoplastic materials that are suitable for substrates, mention may be made of (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 allyl carbonates (co) polymers, ethylene / vinyl acetate thermoplastic copolymers, polyesters such as poly (terephthalate), ethylene) (PET) or poly (butylene terephthalate) (PBT), polyepisulfides, polyepoxides, polycarbonate / polyester copolymers, copolymers of cycloolefins such as ethylene / norbornene or ethylene / cyclopentadiene copolymers and combinations thereof.

By (co) polymer is meant a copolymer or a homopolymer. By (meth) acrylate is meant an acrylate or a methacrylate. For the purposes of the present invention, polycarbonate (PC) is intended to mean homopolycarbonates as well as copolycarbonates and copolycarbonates which are sequenced.

Especially recommended substrates are substrates obtained by (co) polymerizing the bis allyl carbonate of diethylene glycol, sold, e.g., under the CR-39 ^® tradename available from PPG Industries (ORMA ^® ESSILOR lenses), or polythiourethane substrates / polysulfides obtained for example by polymerization of the products sold under the trade name MR6, MR7, MR8, MR10, MR1.74 by the company MITSUI.

Other recommended substrates are polycarbonates.

As shown in FIGS. 1 and 2, the substrate 2 of the ophthalmic lens 1 has a front main face 3 and a rear main face 4.

By main rear side is meant the main face which, when using the ophthalmic lens, is closest to the eye of the user. This is usually a concave face. Conversely, the main front face means the main face which, when using the ophthalmic lens, is the furthest away from the eye of the user. This is usually a convex face.

As indicated above, the substrate 2 of the ophthalmic lens 1 may comprise different coatings either on the main front face 3 of the ophthalmic lens 1 or on the rear main face 4 of the ophthalmic lens 1.

When the substrate has no coating, it is called bare substrate. 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 3, 4 of the substrate 2,

(ii) is not necessarily in contact with the substrate 2, that is to say that one or more intermediate coatings can be arranged between the substrate 2 and the coating in question, and

(iii) does not necessarily completely cover the main face of the substrate 2 on which it is deposited.

When "a layer A is located under a layer B", it will be understood that the layer B is further away from the substrate than the layer A.

According to the invention, the ophthalmic lens 1 comprises a photonic crystal layer 5 covering at least partly one of the main faces of the substrate 2, here the main front face 3 (see Figures 1 and 2).

In the particular embodiment described here, the photonic crystal layer 5 covers the whole of the main front face 3 of the ophthalmic lens 1, that is to say more than 99% of this surface of the main face.

In another embodiment, the photonic crystal layer may cover substantially all of one of the major faces of the substrate. It may for example cover at least 90% or more than 95% of the total surface of the main face on which it is deposited.

In other embodiments, the photonic crystal layer may cover a smaller portion of one of the main faces of the substrate, for example less than 70%, or even less than 50% of the total surface area of the main face. which it is deposited.

In certain embodiments, the ophthalmic lens may comprise two identical or different photonic crystal layers: a first photonic crystal layer on the front main face and a second photonic crystal layer on the rear main face. The first photonic crystal layer, respectively the second layer, can then totally or partially cover the front main face, respectively rear.

In other embodiments, the ophthalmic lens comprises two identical or different photonic crystal layers deposited on the same main face of the substrate: a first photonic crystal layer deposited on this main face and a second layer of photonic crystal deposited on this first layer.

In yet other embodiments, the ophthalmic lens comprises a first and a second photonic crystal layer, identical or different, deposited on the same main face of the substrate, these two layers being adjacent and each partially covering this main face. For example, the first layer may cover a first area of the surface of the main face and the second layer may cover a second area of the surface of the main face. In a preferred embodiment, the photonic crystal layer 5 is deposited directly on the main surface of the bare substrate 2 of the ophthalmic lens 1, here the main front face 3.

Before the deposition of the photonic crystal layer 5, it is common to subject the surface of the substrate 2 to a physical or chemical activation treatment intended to increase the adhesion of the photonic crystal layer 5 to the face or faces. main.

This pretreatment can be conducted under vacuum. It can be a bombardment with energetic species, for example an ion beam ("Ion Pre-Cleaning" or "IPC") or an electron beam, a corona discharge treatment, effluvage , a UV treatment, or a vacuum plasma treatment, generally an oxygen or argon plasma. It can also be an acidic or basic surface treatment and / or by solvents (water or organic solvent).

The photonic crystal layer 5 deposited on the main front face 3 of the substrate 2 of the ophthalmic lens 1 gives the latter optically optical filtering properties.

The light filtering by means of a photonic crystal is based on the principle of the Bragg mirror, the periodic structure of which reflects, by constructive interferences, the incident light for one or more wavelengths, or even for a length band. 'wave.

The periodicity (s) of the structure of the photonic crystal are of the same order of magnitude as the wavelength or wavelengths that one wishes to reflect.

According to a particularly advantageous aspect of the invention, and as represented in FIG. 3, the photonic crystal layer 5 here comprises a matrix 7 and a set of colloidal particles 8 which are arranged in this matrix 7.

Alternatively, the photonic crystal layer may be formed of a matrix containing an arrangement of cavities, for example holes.

The colloidal particles 8 are organized in the matrix 7 according to an ordered three-dimensional network, generally of cubic type - compact centered or hexagonal face (case of FIG. 3).

The volume fraction f _v of particles in the matrix is defined as being the ratio, per unit volume of the photonic crystal layer 5, between the volume occupied by the colloidal particles 8 and the volume occupied by the matrix 7. Typically, the volume fraction f _v may be between 30 and 70%.

In the particular embodiment shown in FIG. 3, the network of colloidal particles 8 in the matrix 7 of the photonic crystal layer 5 is organized periodically, with a longitudinal periodicity Pi (in a plane parallel to the substrate 2) and a transverse periodicity Pt (perpendicular to the substrate 2).

The matrix 7 may be a mineral matrix or an organic matrix, for example a polymer matrix.

The colloidal particles 8 may be mineral particles or particles organic.

Generally, the colloidal particles 8 are of globally spherical or ellipsoidal shape.

Preferably, the matrix 7 is a polymer matrix and the colloidal particles 8 are organic particles (the case of FIG. 3). The polymer matrix 7 and the colloidal particles 8 may consist of a (meth) acrylic resin, a polyester resin, a polycarbonate resin, a polyamide resin, a urethane resin or a resin. polyvinyl, a polyolefin resin, a melamine resin or a mixture of these resins. (Meth) acrylic resins, polyester and polyolefin are recommended.

Conventionally, the photonic crystal is obtained by self-assembly (also referred to as "self-organization") of the organic colloidal particles in the polymer matrix.

Documents US 2013/0171438 and EP2586799 describe how to obtain such photonic crystal layers by self-organization.

In the particular embodiment described here and illustrated in FIG. 4, the colloidal particles 8 are particles of the "core-shell" type (or "core-shell", "core-shell" in English) each comprising a core 9 ("Core") of spherical shape and a bark 10 ("shell") encompassing the entire heart 9.

The heart and the bark may consist of a (meth) acrylic resin, a polyester resin, a polycarbonate resin, a polyamide resin, a urethane resin, a polyvinyl resin, a polyolefin resin, a melamine resin or a mixture of these resins. Colloidal particles with an acrylic resin core and polyvinyl resin bark are recommended.

Each colloidal particle 8 has a diameter D (see FIG. 4). The bark 10 of each colloidal particle 8 has a bark thickness t (see FIG. 4) and an optical index of bark n _sh ; the core 9 has a core diameter equal to Dt and a core optical index n _co .

The matrix 7 has, for its part, an optical index of n _mat matrix.

In the light of FIG. 3, it can be understood that the total thickness E of the photonic crystal layer 5 depends on the number of sub-layers of colloidal particles 8 stacked one on the other to form said layer as well as the spacing between each underlayer.

Typically, the photonic crystal layer 5 comprises between 10 and 150 sub-layers of colloidal particles 8, these having a diameter D of between 100 and 500 nm.

Preferably, the photonic crystal layer 5 has a total thickness E of between 1 and 40 microns, more preferably between 3 and 30 microns.

With a thickness greater than 5 microns and less than 25 microns, it is possible to obtain a satisfactory compromise between the intensity of the light reflection and the efficiency of the filter formed by the photonic crystal layer 5 to limit the transmission of light. blue photo-toxic in the wavelength range of 420 to 450 nm.

In a particular embodiment, a dye is added to the photonic crystal layer. This dye may be a pigment dispersed in the matrix or a dye soluble in the matrix. The dye is generally added to the solution containing a solvent and a composition containing colloidal particles suspended in a matrix prior to being deposited on a substrate or film. The dye may also be added to the matrix or solvent prior to preparing the solvent-containing solution and a composition containing colloidal particles suspended in a matrix.

The added dye does not alter the characteristics of the light reflected by the photonic crystal layer, but may modulate the characteristics of the transmitted color. Thus, for the ophthalmic lens wearer, the added dye modifies the color of the glass to reduce the residual yellow color, unattractive, or to color it according to the wishes of the wearer.

In the present application, the spectral reflectivity, denoted R _k , of the ophthalmic lens 1, for a given angle of incidence on the main front face 3 of the substrate 2, represents the variation of the reflectivity (ie of the energy reflection factor ) at this angle of incidence as a function of the wavelength λ of the incident light.

The spectral reflectivity curve corresponds to a graphical representation of the spectral reflectivity R _K in which the spectral reflectivity (ordinates) is plotted as a function of the wavelength λ (abscissa).

The spectral reflectivity curves can be measured by means of a spectrophotometer, for example a Perkin Elmer Lambda 850 spectrophotometer equipped with URA (Universal Reflectance Accessory).

The average transmission factor in blue, hereinafter denoted T _{m, B} , is defined as being the (unweighted) average of the spectral transmission over the wavelength range extending from 420 nm to 450 nm, corresponding to the photo-toxic blue light (at an angle of incidence less than 17 °, typically 0 °).

The visual transmission factor, denoted T _v , also referred to herein as the average light transmittance, is as defined in IS0 13666: 1998, and measured in accordance with ISO 8980-3 (at an angle of incidence below 17 °, typically 0 °).

Similarly, the visual reflection factor, denoted R _v , also referred to herein as average light reflection factor, is as defined in IS0 13666: 1998, and measured in accordance with ISO 8980-4 (at an angle of incidence less than 17 °, typically 15 °), that is to say that it is the weighted average of the spectral reflectivity R _K over the entire visible light spectrum between 380 nm and 780 nm .

Finally, the chroma, also called "chromaticity" and noted hereinafter, is such that defined by the CIE Lab 76 model.

In the present application, the value of chroma C measured or calculated in reflection on the main front face 3 of the substrate 2 will be considered in particular with an angle of incidence on this main front face which is between 0 ° (normal incidence) and 45 ° (oblique incidence), for a standard illuminant D65 and for a standard observer (10 ° angle).

According to the invention, the ophthalmic lens 1 has:

a spectral reflectivity curve R _k for an angle of incidence on the main front face 3 of between 0 ° and 45 ° which includes a peak of reflectivity having a maximum value of reflectivity at a peak wavelength of between 400 and 460 nanometers, and a value of chroma Ç in reflection on the main face before 3 with an angle of incidence of between 0 ° and 45 ° which is inferior to 30.

Advantageously, the maximum reflectivity value, denoted R _p , of the peak is obtained for a peak wavelength, denoted λ _ρ , which is between 410 and 450 nm, better still between 420 and 450 nm.

This makes it possible to reject more efficiently the blue wavelengths whose photo-toxic effect is the most important.

In a particular embodiment, the ophthalmic lens 1 has a spectral reflectivity curve R _K such that the maximum reflectivity value R _p is greater than 15%, preferably greater than 20%, and even more preferably greater than 30%.

Advantageously, the peak of reflectivity has a width at half height, hereinafter denoted FWHM (for "Full Widht at Half Maximum" in English) which is less than 80 nanometers, preferably less than 50 nanometers, and even more preferably lower at 30 nm.

Advantageously, the value of chroma Ç in reflection is less than 20, better still less than 10.

The photonic crystal layer of the ophthalmic lens functions as a selective interference filter in reflection for phototoxic blue light.

The average transmission factor in the blue T _{m B} can be adjusted by modifying the optical and geometric properties of the photonic crystal layer 5.

For this purpose, it is possible to vary the total thickness E of the photonic crystal layer 5: this makes it possible to adapt the levels of reflection and light transmission, ie the maximum value of reflectivity R _p , for the length of light. peak wave λ _ρ .

The total thickness E can be adjusted by varying the number of sub-layers of colloidal particles 8 forming the photonic crystal layer 5.

Furthermore, the diameter and the refractive index n _co of heart, the thickness t and the refractive index n _sh bark, the refractive index n matrix _mat, the volume fraction f _v of particles in the matrix, or else the longitudinal periodicities Pi and transverse Pt, can also be determined so that the ophthalmic lens 1 has the required optical properties relating to the peak wavelength λ _ρ of the spectral reflectivity peak, the spectral reflectivity R _K and the chroma C of the reflected light.

In a particular embodiment of the invention, the ophthalmic lens 1 has, in transmission through said ophthalmic lens with an angle of incidence of between 0 ° and 45 °, a yellow index of less than 30, preferably less than 20, better than 10.

The YI index (Yellowness Index) is defined according to ASTM D-1925. Yl is determined from the values of tristimulus X, Y, Z defined by the CIE, by the relation: Yl = (128 ^* X - 106 ^* Z) / Y.

The yellow index Yl reflects the tendency of the ophthalmic lens to transmit a light of more or less yellow color.

Particularly advantageously, the ophthalmic lens 1 has, for an angle of incidence between 0 ° and 45 °, a mean transmission factor in the blue T _{m B} , over a range of wavelengths ranging from 420 to 450 nm, less than 80%, preferably less than 70%, better still less than 60%.

In some embodiments, the ophthalmic lens 1 has a mean light transmittance factor T _v (see definition above) greater than 92%, better than 95%.

In other embodiments, the ophthalmic lens 1 also has a mean light reflection factor R _{v of} less than 2.5%, better still less than 1.5%.

The ophthalmic lens 1 of the invention may comprise on one and / or the other main face 3, 4 of the substrate 2 a functional layer covering all or part of said main face 3, 4 of the substrate 2.

This functional layer may be, for example: an anti-shock layer, an anti-abrasion layer, an adhesive coating, a barrier coating, an anti-static layer, an antifouling layer, an anti-reflection coating, an anti-scratch layer, mist, a layer of tint, a polarizing layer, a photochromic layer, etc.

Thus, in the particular embodiment shown in FIGS. 1 to 4, the ophthalmic lens 1 comprises an anti-reflection coating 6 deposited on the rear main surface 4 of the substrate 2. The anti-reflection coating here covers the entire surface of the substrate. the rear main face 4.

Examples of high index and low index layer anti-reflective coatings are described in WO 2008/107325 and WO 2012/076714.

According to another embodiment, the antireflection coating may be deposited on the photonic crystal layer, that it is deposited on the main front face or on the rear main face of the substrate.

In all cases, it can advantageously be provided to insert an anti-abrasion layer between the photonic crystal layer and the anti-reflection coating. It is possible in the ophthalmic lens 1 according to the invention to dissociate the selective filtering function of the photo-toxic blue light by virtue of the photonic crystal layer 5 and the anti-reflection function by virtue of the anti-reflection coating 6.

The ophthalmic lens thus obtained has higher performance levels than an ophthalmic lens providing the functions of selective filtering and anti-reflection by means of a single system, for example a stack of dielectric thin layers.

Generally, the photonic crystal layer can be deposited directly on a bare substrate.

For certain substrates, it is preferable that the main face of the ophthalmic lens comprising the photonic crystal layer is coated with one or more functional coatings prior to the formation of the filter on this main face, for example an adhesive coating and / or a barrier coating.

Generally, the main front and / or rear face of the substrate on which the photonic crystal layer is deposited is then coated with functional coatings, conventionally used in optics, which may be, without limitation: a layer of primer anti-shock, a coating anti abrasion and / or anti-scratch, a polarizer coating, a colored coating, an anti-reflective coating.

The ophthalmic lens according to the invention may also comprise coatings formed on the photonic crystal layer and capable of modifying its surface properties, such as hydrophobic and / or oleophobic coatings ("anti-fouling top coat") and / or anti-fog coatings. Such coatings are described, inter alia, in US 7678464. Their thickness is generally less than or equal to 10 nm, preferably 1 nm to 10 nm, more preferably 1 nm to 5 nm.

Typically, an ophthalmic lens according to the invention comprises a substrate successively coated on its main face before a photonic crystal layer according to the invention, with an anti-abrasion and / or anti-scratch layer, with an anti-abrasion coating. -reflet and a hydrophobic and / or oleophobic coating.

The rear principal face of the substrate of the optical article may be successively coated with a layer of anti-shock primer, with an anti-abrasion and / or anti-scratch layer, with an anti-reflection coating which may whether or not it is an anti-UV coating, and a hydrophobic and / or oleophobic coating.

The ophthalmic lens according to the invention is preferably an ophthalmic lens for spectacles, or an ophthalmic lens blank. The ophthalmic lens according to the invention may be non-corrective or corrective. Corrective ophthalmic lenses can be unifocal, bifocal, trifocal or progressive. The invention thus also relates to a pair of spectacles comprising at least one such ophthalmic lens.

It is particularly advantageous for protecting the eye of a wearer from the phototoxicity of blue light. An ophthalmic lens as described above also has the advantage of conferring a better visual comfort to the wearer in the perception of colors.

The ophthalmic lens of the invention, in its various embodiments described above, can be manufactured according to two manufacturing processes also forming part of the invention.

The first method of manufacture relates to a method in which the photonic crystal layer is attached to one of the main faces of the substrate of the ophthalmic lens by means of a plastic film.

According to the invention, this first manufacturing method comprises the following steps: a) depositing on an plastic film an initial layer of a solution containing a solvent and a composition containing colloidal particles suspended in a matrix;

The second method of manufacture relates to a method in which the photonic crystal layer is deposited directly (i.e. without the use of a plastic film) on one of the major faces of the substrate of the ophthalmic lens.

According to the invention, this second manufacturing method comprises the following steps: a ') depositing an initial layer of a solution containing a solvent and a composition containing colloidal particles suspended in a matrix on at least one of the main faces front and back of a substrate of the ophthalmic lens;

c ') solidifying the matrix of the intermediate layer.

The following examples illustrate the invention in a more detailed but nonlimiting manner, in particular the various methods of manufacturing an ophthalmic lens according to the invention.

In particular, Examples 1 to 4 below relate to ophthalmic lenses manufactured according to the first manufacturing method. Examples 6 to 8 relate to them ophthalmic lenses manufactured according to the second manufacturing method. EXAMPLES

1) Examples 1 to 4 - Getting œuyre n ⁰ 1: crystal LACOUCHE photonic deposit by means of a plastic film

In these first examples, the photonic crystal layer is deposited on a thermoplastic film which is itself transferred to the ophthalmic lens by thermoforming.

More specifically, according to a particular embodiment, in a first step of the process (step a), polyethylene terephthalate (also called polyethylene terephthalate or polyethylene terephthalate in English, abbreviated hereinafter) is deposited on a flat plastic film. PET) 80 microns thick an initial layer of a solution containing:

a solvent in the form of glycol acetate; and

a composition as described in EP 2586799 and containing: an acrylate polymer matrix of refractive index n _mat = 1.6; and

organic colloidal particles suspended in the matrix with a volume fraction f _v = 40%, the colloidal particles being of "core-shell" type with an acrylic resin core of diameter Dt = 160 nm and optical index n _co = 1, 49 and a polystyrene bark of thickness t = 70 nm and optical index n _sh = _1.60 .

The deposition of the initial layer (wet thickness = 30 μηι) on the PET film can for example be carried out by bar coating or spin coating.

In a second step (step b), the initial layer deposited on the PET film is concentrated so that the colloidal particles arrange in the matrix and form an intermediate layer of photonic crystal on the PET film.

This concentration may comprise the evaporation of the solvent from the initial layer, for example by drying in a forced convection oven of the initial layer for 50 minutes at a temperature of 80 ° C. The thickness of the intermediate layer after evaporation of the solvent is approximately 12 μηι.

In a third step (step c), the matrix of the intermediate layer is solidified on the plastic film to form the photonic crystal layer on the PET film.

This solidification is here carried out by polymerization under ultra-violet light (UV) of the polymer matrix. The UV dose (hydrogen lamp, polymerization wavelength = 365 nm) generally used for a total polymerization of the matrix is between 500 and 2000 millijoules per centimeter-square (mJ / cm ² ).

In a fourth step (step d), the PET film is applied to the ophthalmic lens so as to secure the photonic crystal layer on the front main surface of the ophthalmic lens substrate. The transfer of the PET film onto the substrate can be carried out by rolling (thermoforming then transfering) by means of an adhesive on the main front face of the substrate of the ophthalmic lens, as described in documents FR 2883984 and FR 2918917.

In Examples 1 to 4 below, the transfer of the plastic film is performed on an ophthalmic lens comprising a piano substrate (parallel main faces) of organic material MR8 of thickness 2 mm. The ophthalmic lens thus manufactured comprises a single layer of photonic crystal of thickness E on its main front face.

FIG. 5 shows the spectral reflectivity curves C1, C2 as a function of the wavelength between 380 nm and 580 nm for:

curve C1: the PET film covered by the photonic crystal layer (see above); and

curve C2: an antireflection coating alone as described in the international application WO 2013/171434 (example 1).

If both systems have similar blue transmittance values T _{m B} around 75-80%, the selectivity of the blue photo-toxic light cut-off is clear for the PET film covered by the photonic crystal layer. .

The low reflectivity of the photonic crystal system (curve C1) outside of its reflection peak 1 1 prevents the residual color reflected by the front face is too intense (low chroma).

This can also be understood in the light of Tables 1 and 2 below, in which:

Comparative Example 1 corresponds to Example 1 of International Application WO 2013/171434; and

Comparative Example 2 corresponds to Example 3 of International Application WO 2013/171434.

Table 1 Reflection Reflection Transmission

Thickness

luminous average luminous E (Mm)

Rm (%) Rv (%) Tv (%)

Example 1 6 5.9 4.5 90

Example 2 12 6.2 4.5 89

Example 3 6.14.8

Comparative Example 1 - 3.0 0.6 98

Comparative Example 2 - 8.7 1, 7 98

Table 2

Table 1 shows that the chroma C values of the reflected light (measured at an angle of incidence of 15 ° on the main front face of the substrate, for a standard illuminant D65 and for a standard observer (10 ° angle )) Examples 1 to 3 corresponding to ophthalmic lenses according to the invention are much lower, less than 30, than for Comparative Examples 1 and 2 corresponding to inorganic interference filters based on alternating oxide layers; low and high refractive indices and partly reflective of photo-toxic blue light. This is particularly true with a mean transmission factor in the blue Tm, comparable B (see Example 2 and Comparative Example 2: T _m , _B = 62%).

It is also noted in these tables that the yellow Yl values of the light transmitted by the ophthalmic lenses of the invention are lower than those of the comparative examples.

FIG. 6 shows the curves C3, C4, C5, C6 of spectral transmission Τ _λ as a function of the wavelength λ between 380 nm and 580 nm for the various ophthalmic lenses (respectively examples 1, 2, 3 and 4) according to the invention with different total thicknesses E for the photonic crystal layer.

This FIG. 6, associated with Table 3 below, shows that the yellow Y1 index values increase with the thickness but also that the total thickness E of the photonic crystal layer makes it possible to control the breaking performance for the photo-toxic blue light.

Table 3

2) Examples 5 to 8 - Embossing No. 2: direct deposition of the photonic crystal layer on the substrate In Examples 5 to 8 below, the photon crystal layer was deposited directly on the substrate of the ophthalmic lens, said substrate being here an organic glass type CR39 (glass sold under the name ORMA ^® by ESSILOR).

More specifically, according to a particular embodiment, in a first step of the process (step a '), an initial layer of a solution is deposited on the main front face of the ophthalmic lens substrate containing:

a solvent in the form of glycol acetate; and

a composition as described in EP 2586799 and containing: - an acrylate polymer matrix having an optical index of refraction n = _mat 1, 6; and

organic colloidal particles suspended in the matrix with a volume fraction f _v = 40%, the colloidal particles being of "core-shell" type with an acrylic resin core of diameter Dt = 160 nm and optical index n _∞ = 1, 49 and a polystyrene bark of thickness t = 70 nm and optical index n _sh = _1.60 .

The deposition of the initial layer (wet thickness = 20 μηι) on the CR39 substrate can for example be carried out by spin coating, bar coating or dip coating.

In a second step (step b '), the initial layer deposited on the substrate is concentrated so that the colloidal particles arrange in the matrix and form the intermediate photonic crystal layer on the main front face of the substrate.

This concentration may comprise the evaporation of the solvent from the initial layer, for example by drying in a forced convection oven of the initial layer for 20 minutes at a temperature of 80.degree. The thickness E of the intermediate layer after evaporation of the solvent is 6 or 10 μηι according to the examples (see below).

In a third step (step c '), the matrix of the intermediate layer is solidified to form the photonic crystal layer on the substrate.

Example 5 corresponds to the ophthalmic lens manufactured according to the process above and in which the thickness E of the intermediate layer after evaporation of the solvent is 6 μηι.

In Examples 6 to 8:

Example 6 corresponds to the ophthalmic lens manufactured according to the above method with an anti-abrasion coating as described in the document EP 0614957 deposited on the photonic crystal layer;

Example 7 corresponds to Example 6 with an effective anti-reflective coating in the visible and UV as described in WO 2012/076714;

Example 8 is identical to Example 7 in its structure (crystal layer photonic / anti-abrasion coating / antireflection treatment) but with a thickness E of the intermediate layer after solvent evaporation of 10 μηι.

Comparative example 3 below corresponds to the interferential filter described in document WO 2013/171434 (example 1) deposited on a CR39 substrate.

Tables 4 and 5 below show the different performances of Examples 5 to 8 compared to Comparative Example No. 3.

Table 4

ableau 5

According to these tables, it is found that the chroma value pour for the reflected light (measured for an angle of incidence of 15 ° on the main front face of the substrate, for a standard illuminant D65 and for a standard observer (angle of 10 °)) is lower for ophthalmic lenses according to the invention (Examples 5 to 8) than for the ophthalmic lens of the prior art (Comparative Example 3).

The ophthalmic lenses of the invention therefore have a residual hue in reflection (chroma) less pronounced and yellowing in transmission less noticeable by the wearer.

In addition, the performances in terms of "hue", that is to say the Yl yellow index and the average transmission factor in the blue T _{m B} are governed essentially by the photonic crystal layer: the subsequent additions anti-abrasion coating or anti-reflective treatment do not change these performances.

Moreover, the mean reflection values R _m , the visual reflection factor R _v , and the visual transmission factor T _v are improved by adding the anti-reflection treatment. 3) Examples 9 to 1 1 - Embossing No. 3: direct deposition of the colored photonic crystal layer on the substrate

In Examples 9 to 11 below, the protocol of Example 5 is repeated, but a dye is added to the solution containing a solvent, colloidal particles and a matrix before deposition on a CR39® type substrate.

Table 6 describes the dyes used and their concentrations. Epolight series are available from Epolin, Newark, NJ, USA. SDA series are available from HW Sands, Jupiter, FL, USA.

Table 6

Tables 7 and 8 below show the different performances of the examples (without dye) and 9 to 11 (with dye).

Table 7

Table 8

Ophthalmic lenses containing a dye have properties similar to uncoloured ophthalmic lenses: they have blue transmission factors unchanged around 75% for a photonic crystal thickness of 6 μηι and yellow indices that are weak or slightly negative: transmitted light is perceived as very weakly yellow, or even bluish or pinkish (for the negative values of the yellow index). Finally, the hue and chroma of the reflected light are unchanged because they are governed only by the nature of the photonic crystals.

The addition of antireflection coatings on the ophthalmic lenses of Examples 5 and 9 to 11 would lead to a decrease in the values of R _m and R _v . The ophthalmic lenses according to the invention, which selectively filter the blue photo-toxic light between 420 nm and 450 nm by means of the photonic crystal layer, allow easy industrial management of performance levels as needed.

In particular, the choice of the thickness and the components of the photonic crystal layers makes it possible to design products more simply. In addition, the use of a photonic crystal layer deposited on one of the main faces of the substrate makes it possible to dissociate the selective filtering function of the blue photo-toxic light by this layer of the general anti-reflection function. which can be provided by a conventional interferential filter of the dielectric thin film stack type.

Claims

1. Ophthalmic lens (1) comprising:

a substrate (2) having a front main face (3) and a rear main face (4), and

a photonic crystal layer (5) at least partially covering one of said main faces of the substrate (2),

said ophthalmic lens (1) having:

a curve (C1) of spectral reflectivity (R _K ) for an angle of incidence on said front main face (3) between 0 ° and 45 ° which comprises a reflectivity peak (1 1) having a maximum reflectivity value ( R _p ) at a peak wavelength (λ _ρ ) of between 420 and 450 nanometers, and

a value of chroma (ÇJ in reflection on said front main face (3) with an angle of incidence between 0 ° and 45 ° qii is less than 30.

2. Ophthalmic lens (1) according to claim 1, having, in transmission through said ophthalmic lens (1) with an angle of incidence of between 0 ° and 45 °, a yellow index (Y1) of less than 30, preferably less than 20.

3. Ophthalmic lens (1) according to one of claims 1 and 2, wherein said maximum value of reflectivity (R _p ) is greater than 15%.

4. Ophthalmic lens (1) according to one of claims 1 to 3, wherein said peak reflectivity (1 1) has a width at half height (FWHM) less than 80 nanometers, preferably less than 50 nanometers.

The ophthalmic lens (1) according to one of claims 1 to 4, wherein said chroma value (JC is less than 20.

6. Ophthalmic lens (1) according to one of claims 1 to 5, having, for an angle of incidence between 0 ° and 45 °, a mean transmission factor in the blue (T _{m, B} ), on a range of wavelengths ranging from 420 to 450 nanometers, less than 80%.

7. Ophthalmic lens (1) according to one of claims 1 to 6, having a mean transmittance factor (T _v ) greater than 92%.

8. Ophthalmic lens (1) according to one of claims 1 to 7, having a mean light reflection factor (R _v ) less than 2.5%.

9. Ophthalmic lens (1) according to one of claims 1 to 8, wherein said photonic crystal layer (5) is formed of a matrix (7) and colloidal particles (8) arranged in said matrix (7) .

10. Ophthalmic lens (1) according to one of claims 1 to 9, wherein said photonic crystal layer (5) has a thickness (E) of between 1 and 40 micrometers, preferably between 3 and 30 micrometers.

1 1. An ophthalmic lens (1) according to one of claims 1 to 10, wherein said photonic crystal layer (5) comprises a dye.

The ophthalmic lens (1) according to claim 1, wherein said photonic crystal layer (5) has:

a spectral reflectivity curve for an angle of incidence between 0 ° and 45 ° which comprises a reflectivity peak having a maximum reflectivity value at a wavelength of between 420 and 450 nanometers, and

a chroma value in reflection on said layer with an angle of incidence between 0 ° and 45 ° which is less than 30.

13. A method of manufacturing an ophthalmic lens (1) comprising the following steps:

a) depositing on an plastic film an initial layer of a solution containing a solvent and a composition containing colloidal particles (8) suspended in a matrix (7);

b) evaporating at least part of the solvent from the initial layer deposited on said plastic film so that the colloidal particles (8) arrange in said matrix (7) to form a photonic crystal interlayer on said plastic film;

c) solidifying the matrix (7) of said intermediate layer on said plastic film to form a photonic crystal layer (5) on said plastic film; and

d) applying said plastic film to said ophthalmic lens (1) so as to secure said photonic crystal layer (5) on at least one of the front and back main faces of a substrate (2) of the ophthalmic lens (1). )

characterized in that the composition implemented in step a) is adapted so that the ophthalmic lens (1) has:

a spectral reflectivity curve for an angle of incidence on said front main face (3) between 0 ° and 45 ° which comprises a reflectivity peak having a maximum reflectivity value at a peak wavelength between 420 and 450 nanometers, and

a chroma value (Ç_) in reflection on said front main face (3) with an angle of incidence between 0 ° and 45 ° qii is less than 30.

14. A method of manufacturing an ophthalmic lens (1) comprising the following steps:

a ') depositing an initial layer of a solution containing a solvent and a composition containing colloidal particles (8) suspended in a matrix (7) on at least one of the main front and rear faces of a substrate (2 ) of the lens ophthalmic (1);

b ') evaporating at least part of the solvent from the initial layer deposited on said main face so that the colloidal particles (8) arrange in said matrix (7) to form a photonic crystal interlayer; and

c ') solidifying the matrix (7) of the intermediate layer,