Ophthalmic tinted lens

Abstract

An ophthalmic tinted lens has a visual transmission value TV for quantifying a first light intensity ratio which relates to light effective for human vision and transmitted through the lens in daylight condition, and also has a value of a chronobiological factor FC for quantifying a second light amount ratio which relates to light effective for a non-visual physiological effect and also transmitted through the lens in daylight condition. The TV-value and the FC-value expressed as percentage values meet the following condition: FC>1.1×TV+13.0 with 3%≤TV≤43%, or FC>0.7×TV+32 with 43%<TV≤92%, for the ophthalmic tinted lens to combine solar protection and maintenance of circadian rhythms and better pupil constriction which are based on the non-visual physiological effect.

Claims

1. Ophthalmic tinted lens having a visual transmission value T.sub.V for quantifying a first light intensity ratio which relates to light effective for human vision and transmitted through the lens in daylight condition, and a value of a chronobiological factor F.sub.C for quantifying a second light amount ratio which relates to light effective for a non-visual physiological effect and also transmitted through the lens, the light effective for the non-visual physiological effect being also involved in the human vision, wherein the T.sub.V-value and the F.sub.C-value expressed as percentage values meet the following condition: F.sub.C>1.1×T.sub.V+13.0 with 3%≤T.sub.V≤43%, or F.sub.C>0.7×T.sub.V+30.2 with 43%<T.sub.V≤92%.

2. The ophthalmic tinted lens according to claim 1, wherein the visual transmission value T.sub.V is computed using the following formula: $T_V=\frac{{\int }_{380\mathrm{nm}}^{780\mathrm{nm}}{E}_s\left(\lambda \right).Math.V\left(\lambda \right).Math.T\left(\lambda \right).Math.d\lambda }{{\int }_{380\mathrm{nm}}^{780\mathrm{nm}}{E}_s\left(\lambda \right).Math.V\left(\lambda \right).Math.d\lambda }$ where: λ is light wavelength within the visible range 380 nm to 780 nm of the human vision, T(λ) is a spectral transmittance value of the ophthalmic tinted lens at wavelength λ, expressed as a percentage value, V(λ) is a value at wavelength λ of a spectral sensitivity profile V of a human eye for photopic vision, and E.sub.s(λ) is a value at wavelength λ of a spectral intensity distribution E.sub.s of solar light, and the chronobiological factor F.sub.C is an average value of the spectral transmittance values T(λ) across the wavelength range 460 nm to 510 nm, or 465 nm to 495 nm, said range corresponding to maximum sensitivity of melanopsin.

3. The ophthalmic tinted lens according to claim 2, wherein $F_C=\frac{1}{50}.Math.{\int }_{460\mathrm{nm}}^{510\mathrm{nm}}T\left(\lambda \right).Math.d\left(\lambda \right)\mathrm{or}{F}_C=\frac{1}{30}.Math.{\int }_{465\mathrm{nm}}^{495\mathrm{nm}}T\left(\lambda \right).Math.d\lambda .$

4. The ophthalmic tinted lens according to claim 2, wherein the spectral intensity distribution E.sub.s of the solar light used for computing the T.sub.V-value matches CIE Standard illuminant D65.

5. The ophthalmic tinted lens according to claim 1, further having a value of a blue-violet protection factor F.sub.BV for quantifying an efficiency of the lens to protect the human eye against hazard due to blue-violet solar light, said blue-violet protection factor F.sub.BV being computed as 100 minus another value which quantifies a third light amount ratio which relates to light belonging to the wavelength range 415 nm to 455 nm and also transmitted through the lens, wherein the T.sub.V-value and the F.sub.BV-value expressed as percentage values meet the following condition: F.sub.BV>−0.7×T.sub.V+107 if 10%≤T.sub.V≤92%.

6. The ophthalmic tinted lens according to claim 5, wherein the blue-violet protection factor F.sub.BV is computed as 100 minus an average value of the spectral transmittance values T(λ) across the wavelength range 415 nm to 455 nm, said range corresponding to maximum retinal hazard due to blue-violet light.

7. The ophthalmic tinted lens according to claim 6, wherein $F_{\mathrm{BV}}=100-\frac{1}{40}.Math.{\int }_{415\mathrm{nm}}^{455\mathrm{nm}}T\left(\lambda \right).Math.d\lambda .$

8. The ophthalmic tinted lens according to claim 5, wherein the F.sub.C-value and the F.sub.BV-value expressed as percentage values meet the following condition: F.sub.C>−1.0×F.sub.BV+124.

9. The ophthalmic tinted lens according to claim 5, wherein a global efficiency factor F.sub.TOT equal to a sum of the F.sub.C-value and F.sub.BV-value expressed as percentage values, divided by two, is higher than 62%.

10. Solar protection equipment, comprising a spectacle frame suitable for fitting on a wearer's face, and two ophthalmic tinted lenses each ophthalmic tinted lens having a visual transmission value T.sub.V for quantifying a first light intensity ratio which relates to light effective for human vision and transmitted through the lens in daylight condition, and a value of a chronobiological factor F.sub.C for quantifying a second light amount ratio which relates to light effective for a non-visual physiological effect and also transmitted through the lens, the light effective for the non-visual physiological effect being also involved in the human vision, wherein the T.sub.V-value and the F.sub.C-value expressed as percentage values meet the following condition: F.sub.C>1.1×T.sub.V+13.0 with 3%≤T.sub.V≤43%, or F.sub.C>0.7×T.sub.V+30.2 with 43%<T.sub.V≤92%.

11. The ophthalmic tinted lens according to claim 3, wherein the spectral intensity distribution E.sub.s of the solar light used for computing the T.sub.V-value matches CIE Standard illuminant D65.

12. The ophthalmic tinted lens according to claim 2, further having a value of a blue-violet protection factor F.sub.BV for quantifying an efficiency of the lens to protect the human eye against hazard due to blue-violet solar light, said blue-violet protection factor F.sub.BV being computed as 100 minus another value which quantifies a third light amount ratio which relates to light belonging to the wavelength range 415 nm to 455 nm and also transmitted through the lens, wherein the T.sub.V-value and the F.sub.BV-value expressed as percentage values meet the following condition: F.sub.BV>−0.7×T.sub.V+107 if 10%≤T.sub.V≤92%.

13. The ophthalmic tinted lens according to claim 3, further having a value of a blue-violet protection factor F.sub.BV for quantifying an efficiency of the lens to protect the human eye against hazard due to blue-violet solar light, said blue-violet protection factor F.sub.BV being computed as 100 minus another value which quantifies a third light amount ratio which relates to light belonging to the wavelength range 415 nm to 455 nm and also transmitted through the lens, wherein the T.sub.V-value and the F.sub.BV-value expressed as percentage values meet the following condition: F.sub.BV>−0.7×T.sub.V+107 if 10%≤T.sub.V≤92%.

14. The ophthalmic tinted lens according to claim 4, further having a value of a blue-violet protection factor F.sub.BV for quantifying an efficiency of the lens to protect the human eye against hazard due to blue-violet solar light, said blue-violet protection factor F.sub.BV being computed as 100 minus another value which quantifies a third light amount ratio which relates to light belonging to the wavelength range 415 nm to 455 nm and also transmitted through the lens, wherein the T.sub.V-value and the F.sub.BV-value expressed as percentage values meet the following condition: F.sub.BV>−0.7×T.sub.V+107 if 10%≤T.sub.V≤92%.

15. The ophthalmic tinted lens according to claim 11, further having a value of a blue-violet protection factor F.sub.BV for quantifying an efficiency of the lens to protect the human eye against hazard due to blue-violet solar light, said blue-violet protection factor F.sub.BV being computed as 100 minus another value which quantifies a third light amount ratio which relates to light belonging to the wavelength range 415 nm to 455 nm and also transmitted through the lens, wherein the T.sub.V-value and the F.sub.BV-value expressed as percentage values meet the following condition: F.sub.BV>−0.7×T.sub.V+107 if 10%≤T.sub.V≤92%.

16. The ophthalmic tinted lens according to claim 6, wherein the F.sub.C-value and the F.sub.BV-value expressed as percentage values meet the following condition: F.sub.C>−1.0×F.sub.BV+124.

17. The ophthalmic tinted lens according to claim 7, wherein the F.sub.C-value and the F.sub.BV-value expressed as percentage values meet the following condition: F.sub.C>−1.0×F.sub.BV+124.

18. The ophthalmic tinted lens according to claim 6, wherein a global efficiency factor F.sub.TOT equal to a sum of the F.sub.C-value and F.sub.BV-value expressed as percentage values, divided by two, is higher than 62%.

19. The ophthalmic tinted lens according to claim 7, wherein a global efficiency factor F.sub.TOT equal to a sum of the F.sub.C-value and F.sub.BV-value expressed as percentage values, divided by two, is higher than 62%.

20. The ophthalmic tinted lens according to claim 8, wherein a global efficiency factor F.sub.TOT equal to a sum of the F.sub.C-value and F.sub.BV-value expressed as percentage values, divided by two, is higher than 62%.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a general view of an ophthalmic tinted lens and a solar protection equipment according to the present invention.

(2) FIG. 2a is a spectral absorption diagram of melanopsin;

(3) FIG. 2b is a diagram displaying two blue-violet hazard spectra.

(4) FIG. 3 is a first diagram which compares lenses according to the present invention with lenses existing prior to the invention, in T.sub.V- and F.sub.C-coordinates.

(5) FIG. 4 is a second diagram which compares lenses according to the present invention with lenses existing prior to the invention, in T.sub.V- and F.sub.BV-coordinates.

(6) FIG. 5 is a third diagram which compares lenses according to the present invention with lenses existing prior to the invention, in F.sub.BV- and F.sub.C-coordinates.

(7) FIG. 6 is a fourth diagram which compares lenses according to the present invention with lenses existing prior to the invention, in and T.sub.V- and F.sub.TOT-coordinates.

(8) FIG. 7 is a diagram which compares respective light transmittance spectra of four lenses according to the present invention and three lenses existing prior to the invention.

DETAILED DESCRIPTION OF THE INVENTION

(9) In FIG. 1, reference number 1 denotes an ophthalmic tinted lens which is exposed to impinging light. The light ray R passes through the lens 1 and enters into the eye 10 of a wearer who is equipped with the ophthalmic tinted lens 1. To this purpose, the lens 1 is mounted into a spectacle frame 2 so as to form the solar protection equipment 11.

(10) The spectral light transmittance T(λ) of the ophthalmic tinted lens 1 can be measured in a well-known manner, for example using a spectrophotometer. As a non-limiting example, the light ray R may be oriented perpendicular to the lens 1 during the measurements. Then, the visual transmission T.sub.V of the lens 1, which quantifies the intensity ratio of the light which participates to human photopic vision, may be calculated using the above formula (1), where the spectral intensity values of the illuminant D65 may be used for the spectral intensity distribution E.sub.s, as defined by the standard ISO 8980-3:2013. The spectral sensitivity profile V of the human eye for photopic vision is defined by CIE Standard ISO 10526:1999/CIE 5005/E-1998.

(11) The chronobiological factor F.sub.C may be provided generally by the following second formula:

(12) $\begin{array}{cc}{F}_C=\frac{{\int }_{m_1}^{m_2}{E}_s\left(\lambda \right).Math.M\left(\lambda \right).Math.T\left(\lambda \right).Math.d\lambda }{{\int }_{m_1}^{m_2}{E}_s\left(\lambda \right).Math.M\left(\lambda \right).Math.d\lambda }& \left(2\right)\end{array}$
where: m.sub.1 and m.sub.2 are two first wavelength limits comprised between 380 nm and 780 nm, or equal to 380 nm or 780 nm, with m.sub.1 less than m.sub.2; and M(λ) is a value at wavelength λ of a spectral sensibility profile M of the non-visual physiological effect, for the wavelength ranging from m.sub.1 to m.sub.2.

(13) The F.sub.C-value thus computed ranges from 0 to 100, since the spectral transmittance values T(λ) to be inputted in formula (2) range from 0 to 100.

(14) In preferred embodiments of the invention, the spectral intensity distribution E.sub.s of solar light, which is used for computing the T.sub.V-value and F.sub.C-value, may match the CIE Standard illuminant D65.

(15) Possibly, m.sub.1 may equal 380 nm and m.sub.2 may equal 780 nm.

(16) When the chronobiological factor F.sub.C is directed to at least one melanopsin-based physiological effect, the spectral sensitivity profile M may be a spectral absorption profile of melanopsin. In this way, the F.sub.C-value quantifies an efficiency of the invention tinted lens to maintain at least one circadian rhythm for a melanopsin-based physiological effect. FIG. 2a reproduces a spectral absorption of melanopsin as recovered from widely available documents. The horizontal axis of this diagram indicates the wavelength values λ in nanometers, and the vertical axis indicates the melanopsin absorption values, corresponding to M(λ). The melanopsin absorption values for both wavelength values 460 nm and 510 nm are about 0.15 when the maximum absorption value is set to unity. So, the spectral sensitivity profile M for each wavelength value between 380 nm and 780 nm but outside the range from 460 nm to 510 nm, is much less than the maximum value of this spectral sensitivity profile M, such maximum value occurring for a value of the wavelength λ which is comprised between 460 nm and 510 nm. Then, for a melanopsin-based physiological effect, the chronobiological factor F.sub.C can be more focused on the melanopsin absorption range when m.sub.1 equals 460 nm and m.sub.2 equals 510 nm, or m.sub.1 equals 465 nm and m.sub.2 equals 495 nm.

(17) So, when the non-visual physiological effect which is considered is based on melanopsin, the spectral absorption profile of melanopsin can be used for the spectral sensibility profile M. Then, it may be considered that the E.sub.s(λ)-values of the spectral intensity distribution of the solar light are almost constant across the wavelength range from 460 nm to 510 nm, and that the spectral sensitivity profile M has a crenel-shape with values M(λ) which are almost equal to zero outside the wavelength range from 460 nm to 510 nm, and almost constant non-zero values M(λ) between 460 nm and 510 nm. Then, these conditions lead to the F.sub.C-value being computed as

(18) $F_C=\frac{1}{50}.Math.{\int }_{460\mathrm{nm}}^{510\mathrm{nm}}T\left(\lambda \right).Math.d\left(\lambda \right)$
when m.sub.1=460 nm and m.sub.2=510 nm, which involves simplified and more rapid calculations. Similar reasons apply for using alternatively m.sub.1=465 nm and m.sub.2=495 nm.

(19) Low T.sub.V-values indicate that the ophthalmic tinted lens reduces significantly the amount of visible light which enters into the wearer's eye, and high F.sub.C-values indicate that the ophthalmic tinted lens produces good transmission for the light part which is effective for the non-visual physiological effect. In FIG. 3, the horizontal axis of the diagram displayed indicates the T.sub.V-values, and the vertical axis indicates the F.sub.C-values calculated according to the above simplified formula with m.sub.1=465 nm and m.sub.2=495 nm. The diagram compares in this first coordinate system, locations of lenses existing prior to the present invention to lenses which meet the invention. The left segment of the boundary L.sub.1 corresponds to the condition F.sub.C=1.1×T.sub.V+13.0 for 3%≤T.sub.V≤43%, and the right segment of the boundary L.sub.1 corresponds to the condition F.sub.C=0.7×T.sub.V+30.2 for 43%<T.sub.V≤92%. FIG. 3 thus shows that the lenses which existed before the present invention are located in the lower right part of the diagram, with respect to the boundary L.sub.1, whereas the invention lenses are located in the upper left diagram part. This distribution indicates the improvement which is brought by the invention lenses for transmitting light which is effective for a melanopsin-based non-visual physiological effect, while producing a protection against dazzling.

(20) The particular invention sample which is indicated with a square in the diagrams of FIGS. 3 to 6 and called Mirror will be described later.

(21) When the non-visual physiological effect which is desired to be maintained while the wearer is equipped with the lens 1, is melanopsin-based, the sub-part of the spectral range of visible light to be transmitted efficiently through the lens is from about 460 nm to about 510 nm. However, it is well-known that the blue-violet light with wavelength values below 455 nm or 480 nm is harmful for the retina and participates to the ageing of the eye. It is therefore preferable that the lens 1 provides protection against such blue-violet light below 455 nm at the same time it provides efficient transmission between 460 nm and 510 nm. Then, the following formula (3) allows quantifying such protection against harmful blue-violet light:

(22) $\begin{array}{cc}{F}_{\mathrm{BV}}=100-\frac{{\int }_{h_1}^{h_2}{E}_s\left(\lambda \right).Math.B\left(\lambda \right).Math.T\left(\lambda \right).Math.d\lambda }{{\int }_{h_1}^{h_2}{E}_s\left(\lambda \right).Math.M\left(\lambda \right).Math.d\lambda }& \left(3\right)\end{array}$
where: h.sub.1 and h.sub.2 are two second wavelength limits comprised between 380 nm and 780 nm, or equal to 380 nm or 780 nm, with h.sub.1 less than h.sub.2; and B(λ) is a value at wavelength λ of a blue-violet hazard spectrum which matches Standard ISO 8980-3 or experimental photobiology data on retina, for example as defined by Arnault, Barrau et al. in the article entitled “Phototoxic Action Spectrum on a Retinal Pigment Epithelium Model of Age-related Macular Degeneration Exposed to Sunlight Normalized Conditions”, PlosOne. 2013, for the wavelength λ ranging from h.sub.1 to h.sub.2.

(23) The diagram of FIG. 2b shows two spectral profiles of the harmful blue-violet light, denoted B(λ) and B′(λ) respectively, and which can be used alternatively in formula (3). The profile B(λ) is that contained in Standard ISO 8980-3, and the profile B′(λ) is that disclosed in the PlosOne reference indicated above.

(24) In a way similar to that applied for the chronobiological factor F.sub.C as initially expressed according to formula (2), it may be considered that the E.sub.s(λ)-values of the spectral intensity distribution of solar light are almost constant across the wavelength range from 415 nm to 455 nm, and that the harmful blue-violet profile B(λ) or B′(λ) is similar to a crenel-shape, with values which are almost equal to zero outside the wavelength range from 415 nm to 455 nm, and almost constant non-zero values between 415 nm and 455 nm. Then, the F.sub.BV-value may be computed as

(25) $F_{\mathrm{BV}}=100-\frac{1}{40}.Math.{\int }_{415\mathrm{nm}}^{455\mathrm{nm}}T\left(\lambda \right).Math.d\lambda ,$
which involves simplified and more rapid calculations. In FIG. 4, the horizontal axis of the diagram displayed indicates the T.sub.V-values again, but the vertical axis indicates the F.sub.BV-values calculated in this simplified way. The diagram compares in this second coordinate system, locations of the lenses existing prior to the present invention to the lenses which meet the invention. The continuous straight line L.sub.2 corresponds to formula F.sub.BV=−0.7×T.sub.V+107 for 10%≤T.sub.V≤92%. FIG. 4 then shows that the lenses which existed before the present invention are located in the lower left part of the diagram, with respect to the boundary line L.sub.2, whereas the invention lenses are located in the upper right diagram part. This distribution indicates the improvement which is brought by the invention lenses for protecting against the blue-violet light hazard while simultaneously producing an efficient protection against dazzling.

(26) In FIG. 5, the horizontal axis of the diagram displayed indicates the F.sub.BV-values, and the vertical axis indicates the F.sub.C-values. The diagram compares in this third coordinate system, locations of the lenses existing prior to the present invention to the lenses which meet the invention. The continuous straight line L.sub.3 corresponds to formula F.sub.C=−1.0×F.sub.BV+124. FIG. 5 then shows that the lenses which existed before the present invention are located mainly in the lower left part of the diagram, with respect to the boundary line L.sub.3, whereas the invention lenses are located in the upper right diagram part. This distribution indicates the improvement which is brought by the invention lenses for producing an efficient protection against harmful blue-violet light while transmitting enough light effective for the melanopsin-based non-visual physiological effect.

(27) The half-sum of both F.sub.C- and F.sub.BV-values quantifies the capability of a lens to provide an efficient protection against harmful blue-violet light and simultaneously transmitting light which is effective for the melanopsin-based non-visual physiological effect. In FIG. 6, the horizontal axis of the diagram displayed indicates the T.sub.V-values, and the vertical axis indicates the values for F.sub.TOT=0.5.Math.(F.sub.C+F.sub.BV). The diagram compares in this fourth coordinate system, locations of the lenses existing prior to the present invention to the lenses which meet the invention. The continuous straight line L.sub.4 corresponds to F.sub.TOT=62%. The diagram shows that the lenses which existed before the present invention are located in the lower part of the diagram, with respect to the boundary line L.sub.4, whereas the invention lenses are located in the upper diagram part. This distribution indicates the improvement which is brought by the invention lenses for producing efficient protection against harmful blue-violet light while being efficient for transmitting light effective for the melanopsin-based non-visual physiological effect.

(28) Table 1 below recites the dies and absorbers that are used for three invention lenses which are labelled #1, #2 and #3, with their respective concentrations. For these three lenses, the lens base material is Trivex™ as supplied by PPG Industries, and which is based on polyurethane polymer. The concentrations are expressed in mg (milligram) of each dye or absorber for 100 g of the resulting blend of Trivex™ with the dies and absorbers. Commercial suppliers are also indicated between parentheses.

(29) TABLE-US-00001 TABLE 1 concentrations dyes absorbers #1 #2 #3 Solvent Green 3 0 2.6 2.7 Macrolex Green 5B 4 0 0 (Lanxess AG)) Estofil Blue RR 5 0 0 (Sandoz Ltd) Macrolex Yellow G 1.8 2.5 2.1 (Lanxess AG) Macrolex Red H 0 1.1 1 (Lanxess AG) Ancroplast Blue 2RC 0 7.6 6.4 Exciton ABS584L 1 1.7 1.2 (Exciton) Macrolex Violet 3R 1 1.7 1.3 (Lanxess AG) Exciton ABS526 1.5 1.9 1.6 (Exciton) Yamada FDB002 6 6.3 5.3 (Yamada Chemical Co., Ltd.) Gentex A102 0.5 0.8 0.7 (Gentex)

(30) These dyes and absorbers match the transmission and absorption features recited in the general part of the description for the third invention aspect. In particular, the dyes are mainly responsible for the shape of the lens transmittance profile for wavelength values between 380 nm and 460 nm, whereas the absorbers are mainly responsible for the shape of the lens transmittance profile for wavelength values between 510 nm and 780 nm. For reciting the connections with the general part of the invention description: Macrolex Yellow G is a die which participates to obtaining a T.sub.V-value of less than 0.6.Math.T.sub.V at a first wavelength value between 415 nm and 455 nm; Exciton ABS526, Yamada FDB002 and Gentex A102 are absorbers which are efficient for absorbing in the range 525 nm-550 nm; and Exciton ABS584L is another absorber which is efficient for absorbing in the range 570 nm-590 nm.

(31) With these compositions, lens #1 is blue-green in transmission and has a transmission colorimetric a*-value which is equal to −35, lens #2 is greyish in transmission and has another transmission colorimetric a*-value which is equal to −7.8, and lens #3 is greyish in transmission too but with a*-value of −10.

(32) A further ophthalmic tinted lens in accordance with the invention has been produced from the above lens #1, by applying the following transmission-selective stack on the convex face of this lens: silica (SiO.sub.2): 41.4 nm (nanometer), zirconia (ZrO.sub.2): 52.2 nm, silica: 117.4 nm and zirconia: 65.5 nm, and also by applying the antireflective coating called Crizal F® and produced by Essilor on the concave face of the lens. This further ophthalmic tinted lens has been labelled Mirror in FIGS. 3 to 6, and #1-Mirror/AR in table 2 below and FIG. 7.

(33) Still another ophthalmic tinted lens in accordance with the invention has been produced from the lens #1, by applying the antireflective coating Crizal F® on both its concave and convex faces. The tinted lens thus obtained is labelled #1-AR/AR in table 2 below and FIG. 7.

(34) With the dyes and absorbers of table 1 and their respective concentrations, the following numerical values have been obtained for the above described lenses, using the illuminant D65 and the calculation parameters indicated therein:

(35) TABLE-US-00002 TABLE 2 #1 #2 #3 #1-AR/AR #1-Mirror/AR T.sub.V 380 nm-780 nm 24 17 20 26 19 F.sub.C Crenel-shape melanopsin 58 37 42 62 54 absorption profile m.sub.1 = 465 nm; m.sub.2 = 495 nm F.sub.BV Crenel-shape hazard profile 98 99 99 97 97 h.sub.1 = 415 nm; h.sub.2 = 455 nm

(36) FIG. 7 compares spectral light transmittance profiles of four among these invention lenses, with three lenses which existed before the invention. The horizontal axis indicates the wavelength values λ in nanometers, from 380 nm to 780 nm, and the vertical axis indicates the spectral light transmittance values T(λ) for all lenses. The thickness of the base lens material for the seven lenses is 2 mm (millimeter). It appears that the invention lenses exhibit profiles which are much more shaped, with lower transmittance values for wavelength values below 450 nm, higher transmittance values between 460 nm and 510 nm, and a deeper decrease of the transmittance between about 510 nm and 570 nm. The four invention lenses considered in FIG. 7 are #1-AR/AR, #1-Mirror/AR, #2 and #3. Each of them has a average transmittance value in the wavelength range 465 nm-495 nm which amounts to between 30% and 90%. Transmittance is higher than 70% in the range 750 nm-780 nm for all lenses represented.

(37) FIG. 7 also shows the narrow wavelength ranges 455 nm-465 nm and 510 nm-520 nm, in which the slopes of the T(λ)-curves may be calculated. Line constructions are also provided for drawing a first slope P.sub.1 equal to 1.4%.Math.nm.sup.−1 and a second slope P.sub.2 equal to −0.5%.Math.nm.sup.−1. Then, it can be checked that the slopes of the transmittance curves for the four invention lenses are steeper than P.sub.1 in the range 455 nm-465 nm, and the slopes in the range 510 nm-520 nm for the same curves are steeper than P.sub.2.

(38) In addition, clinical studies have shown that such ophthalmic tinted lens according to the invention causes a benefit in the pupillary amplitude of constriction of 50%, and in the constriction sustainability of 75%, vs a standard solar lens.

(39) It is clear that the invention may be reproduced while modifying secondary aspects thereof with respect to the embodiments just described in detail, but maintaining the advantages cited. In particular, the chronobiological factor F.sub.C may be computed using summations restrained to the wavelength range from 465 nm to 495 nm, and the blue-violet protection factor F.sub.BV may be computed using summations restrained to the wavelength range from 415 nm to 455 nm.