JP2015118122A - Spectacle lens and spectacles - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a novel spectacle lens which can achieve required and sufficient protection from light in the blue wavelength region and has yellowishness reduced to be preferable in appearance.SOLUTION: The spectacle lens (lens D) has 5% or less transmittance of light at a wavelength of 410 nm and has 85% or more transmittance of light at a wavelength of 440 nm, and a spectral transmittance distribution in the blue wavelength region (for example, 400 to 450 nm) sharply rises like a perpendicular within a region from 410 nm or more to 440 nm or less. Further the spectacle lens has 85% or more luminous transmittance.

Description

  The present invention relates to a spectacle lens capable of protecting eyes and having a good appearance, and spectacles using the spectacle lens.

For the human eye, it is known that ultraviolet rays and light having a wavelength belonging to the blue region, which is the short wavelength side in the visible region, are relatively easily burdened. In addition, eyeglass lenses that reduce blue light are known.
As for the evaluation standard for such an ophthalmic device that cuts blue light, that is, the standard for dimming blue light, British Standard BS 2724 (1987) and European Standard BS / EN 1836 (2005) are known. The former is based on the fact that the light cut rate (100-transmittance [%]) at approximately 380 to 500 nanometers (nm) is a predetermined value or more, and the latter can be obtained based on experiments on animals (monkeys). Based on the obtained data, the cut rate weighted with a predetermined distribution centered at about 450 nm is set as a reference value that is equal to or greater than a predetermined value.
Although these standards indicate the degree of attenuation of blue light in spectacle lenses, the degree of protection against human eyes cannot be measured quantitatively depending on the human eye. The protective effect of the spectacle lens cannot be accurately grasped.

As an attempt to quantitatively grasp the protective effect on the human eye in a form corresponding to the human eye, there is one described in Non-Patent Document 1 below.
In this trial, when inserting an intraocular lens into multiple human eyes by cataract surgery, a group that inserts a lens that cuts short wavelength light (colored intraocular lens) and a lens that does not cut short wavelength light (colorless) Intraocular lenses) are divided into groups to be inserted, and the macular pigment concentration of the surgical latter belonging to each group is measured over time. In addition, the lens which cuts short wavelength light (blue light) is colored yellow which is a complementary color of blue.

The macular pigment has lutein and its isomer zeaxanthin as its main components, and in human eyes, it is known to exist in the lens and the central fovea of the retina (an important part of the retina) Yes. Furthermore, lutein is a kind of carotenoid and is known to exhibit an action of absorbing blue light, and is also known to exhibit an antioxidant action. And lutein in macular pigment prevents blue light from affecting the human eye by the blue light absorption action, prevents blue light from exerting oxidative stress on the human eye by the antioxidant action, It is considered that the eyes are protected so as not to develop eye diseases such as cataracts. Lutein is gradually decomposed by exhibiting these actions, but cannot be synthesized in the human body. It is taken by meal and replenished to the eye as needed.
Non-Patent Document 2 below is a paper on the relationship between lutein intake and the incidence of cataracts in humans. When there is a large amount of lutein, there is a relatively large amount of lutein in the fovea of the lens and retina. It has been shown that the incidence of cataract tends to be low.

In the attempt of Non-Patent Document 1, the difference in protective effect between a colored intraocular lens and a colorless intraocular lens is grasped in a form corresponding to the human eye by continuously measuring the macular pigment concentration in the human eye. Although it is possible, the protective effect cannot be grasped for lenses other than intraocular lenses. In addition, the measurement requires a long period of time, and it is necessary to ask the wearer to measure the macular pigment concentration many times, which takes time to grasp the protective effect. In addition, the macular pigment concentration in the eye may change due to other factors such as nutritional status (eg, differences in the intake of green-yellow vegetables) and stress status (eg, differences in smoking). This is a relatively difficult situation. And when measuring macular density pigments in human eyes, it is difficult to accurately measure the yellowness of the lens and other pigments (for example, melanin pigments), and the reproducibility and stability of the measured values are difficult. In the current situation, there are no established methods for measuring the concentration of macular pigment in the human eye.
Non-Patent Document 1 evaluates the difference in performance related to blue light of a lens that is well colored yellow with respect to a colorless lens. However, when the density of yellow varies, the density difference is particularly small. Evaluation of the difference in performance regarding blue light between lenses at a given time has not been performed anywhere, including Non-Patent Document 1.
In light of the current situation, it would be better to provide a lens evaluation method that can target a variety of lenses and that can more accurately and easily grasp the protective effects on human eyes. It is done.

Now, spectacle lenses that cut blue light will have a yellow color that is a complementary color of blue as the cut rate increases. In many cases, wearing is avoided.
The thing of the following patent document 1 is proposed as an ophthalmic instrument which cuts blue light. This ophthalmic device rapidly absorbs light having a wavelength in the range of about 400 to 450 nm. According to this ophthalmic device, it is said that protection against light in the wavelength range of purple or blue is made, and dark vision is improved.
Patent Document 2 discloses a plastic lens that blocks transmission of infrared rays (near infrared rays having a wavelength of 750 to 1000 nm) in addition to ultraviolet rays (having a wavelength of 400 nm or less). The lens includes a dithiol nickel complex salt as an infrared absorber and an ultraviolet absorber.

JP 2012-22351 A Japanese Patent No. 3188072

Augmentation of Macular Pigment following Implantation of Blue Light-filtering Intraocular Lenses at the Time of Cataract Surgery, John M. Nolan et al., Investigative Ophthalmology & Visual Science, August 2009, Vol. 50, No. 10, p4777-4785 Hien T. V. Vu, Lutein and Zeaxantin and the Risk of Cataract: The Melbourne Visual Impairment Project, Investigative Ophthalmology & Visual Science, September 2006, Vol. 47, No. 9

In Patent Document 1, protection against light in the violet or blue wavelength range is made, but it is relatively dark yellowish, and its wearing may be avoided due to aesthetic resistance. is there.
Moreover, in the thing of patent document 2, although protection with respect to an ultraviolet-ray and a near-infrared is made | formed, protection with respect to blue light is not made.
SUMMARY OF THE INVENTION An object of the present invention is to provide a novel spectacle lens that is capable of sufficiently and sufficiently protecting against light in the blue wavelength range and that has a reduced yellowness and is favorable in appearance. It is what.

In order to achieve the above object, the invention according to claim 1 is an eyeglass lens, wherein the transmittance of light having a wavelength of 410 nm is 5% or less, and the transmittance of light having a wavelength of 440 nm is 85% or more. The luminous transmittance is 85% or more.
The invention according to claim 2 is characterized in that, in the above invention, the average transmittance at a wavelength of 800 to 1500 nm is 80% or less.
The invention described in claim 3 is characterized in that in the above invention, at least one of a pigment or a dye which is at least one of red, blue and purple is further mixed.
According to a fourth aspect of the present invention, in the eyeglasses, the eyeglass lens of the invention is used.

  According to the present invention, it is possible to provide a new spectacle lens that is capable of sufficiently and sufficiently protecting against light in the blue wavelength range, while reducing yellowness and being preferable in appearance. Play.

It is a graph which shows the spectral transmittance distribution in the visible region of the lens concerning a comparative example, and its vicinity. It is a schematic diagram which shows the setting of the lens and lutein at the time of light irradiation in the novel lens evaluation method. It is a graph which shows the spectral transmittance distribution in the wavelength range of 350-600 nm concerning the lutein before light irradiation and each lutein after irradiating light through each lens of FIG. 2 in the novel lens evaluation method. . It is a graph which shows the spectral transmittance distribution in the visible region of the lens which concerns on an Example, and a comparative example, and its vicinity. In the new lens evaluation method, the spectral transmittance distribution in the wavelength region of 350 to 600 nm (average of 12 measurement results) for each lutein after irradiating light through each lens of FIG. 4 is shown. It is a graph. It is a graph about the transmittance | permeability with respect to the light of wavelength 454nm of the lutein after the light irradiation which concerns on each lens of FIG. 4 in the novel lens evaluation method. Color matching functions x (35), y (35), z (35) relating to a 35-year-old standard observer and color matching functions x (60), y (60) relating to a 60-year-old standard observer ), Z (60). In the new lens evaluation method, a for the color of each lens in the chromaticity calculation by the 35-year-old color matching function and the chromaticity calculation by the 60-year-old color matching function for each lens in FIG. 4 (including the lens A in FIG. 1) It is the graph which plotted ^* value and b ^* value on L ^* a ^* b ^* chromaticity diagram. It is a graph which shows the spectral transmittance distribution in the visible region and its vicinity of the prototype lens concerning this invention.

  Hereinafter, examples of embodiments according to the present invention will be described with reference to the drawings as appropriate. In addition, the form of this invention is not limited to the following.

The following can be considered as the spectacle lens according to the present invention.
That is, the transmittance of light having a wavelength of 410 nm is 5% or less (more preferably 2% or less), and the transmittance of light having a wavelength of 440 nm is 85% or more (more preferably 90% or more). . Therefore, the spectral transmittance distribution in the blue wavelength region (for example, 400 to 450 nm) rises rapidly in the region of 410 nm or more and 440 nm or less and becomes a distribution close to a perpendicular line.
Furthermore, the spectacle lens according to the present invention has a luminous transmittance of 85% or more (more preferably 90% or more).
In the spectacle lens according to the present invention, a material that absorbs blue light of less than 440 nm is dispersed in the lens base, an optical multilayer film that reflects the blue light is formed on one or both sides of a transparent lens base, It can be formed by combining these. The material that absorbs blue light of less than 440 nm can be a dye, a pigment, or a combination thereof.
The spectacle lens according to the present invention has a luminous transmittance of 85% or more (more preferably 90% or more), and a transmittance of light having a wavelength of 440 nm is 85% or more (more preferably 90% or more). Therefore, the yellow color is so thin that it cannot be visually recognized, is colorless and transparent, and has an excellent aesthetic appearance.
The spectacle lens according to the present invention is sufficiently effective in protecting against light having a wavelength on the short wavelength side in the visible region (blue light), and is preferably colorless and transparent with almost no yellowishness. It is possible to sufficiently and sufficiently protect against light in the blue wavelength range.

  Next, examples of the present invention according to the above embodiment will be described. In addition, the Example which concerns on the said embodiment is not limited to the following.

[New lens evaluation method]
Before describing examples of the present invention and comparative examples not belonging to the present invention, a novel lens evaluation method for appropriately evaluating the protective effect against blue light will be described.
As described above, it is better to provide a lens evaluation method that can target various lenses and can more accurately and easily grasp the protective effect on human eyes. Thus, it is possible to provide a lens evaluation method that can accurately and easily grasp the protective effect on the human eye, regardless of the shape, density, or the like of the lens.

In this evaluation method, a macular pigment outside the body is used.
As the macular pigment, lutein, zeaxanthin, or a combination thereof can be used.
Further, macular pigment present in the human body (intraocular) is not used, but macular pigment present outside the human body is used. As the macular pigment, those derived from plants, that is, those extracted from plants can be used.
In addition, it is thought that the macular pigment existing in the eye protects the eye (particularly the lens and the central fovea of the retina) from blue light by the blue absorption ability and the antioxidant ability. If the macular pigments in the eye are abundant, the blue absorption ability and the antioxidant ability become high, and it can be said that the eye is healthier.
Hereinafter, although the case where lutein is used as a macular pigment will be described, other macular pigments may be used. Zeaxanthin is an isomer of lutein and exhibits the same action as lutein.

In this evaluation method, the protective effect of the lens is evaluated by applying light in a state where the lens is covered with lutein and measuring the degree of deterioration of the lutein.
That is, after the lutein is irradiated with light through the test lens, the degree of degradation of lutein is measured.

If the degree of deterioration of such lutein with respect to light passing through the lens is measured, the magnitude of the protective effect of the lens corresponding to the human eye can be determined.
For example, if the degree of deterioration of lutein against sunlight through a lens is low (if lutein is difficult to deteriorate) compared to the degree of deterioration of lutein against sunlight that does not pass through the lens, The lutein is protected by the lens, and the protective effect of the lens is higher.
Further, the degree of the protective effect of the lens can be understood by comparing the degree of progress of deterioration. For example, in two lenses, the progress of degradation of lutein with respect to sunlight through each lens is twice as slow as that of sunlight (without lens) (the same degree of degradation is obtained). If the other is 4 times slower, the latter has twice the protective effect than the former.
In short, the greater the degree of degradation of lutein, the lower the protection effect of the lens, and the smaller the degradation level of lutein, the greater the protection effect of the lens. In particular, it can be considered that the protective effect against light (blue light) having a wavelength on the short wavelength side in the visible region can be evaluated in detail.

In this evaluation method, preferably, lutein is put in a container such as a petri dish, a lens is placed on the container and exposed to light.
The light can be sunlight or lamp light such as xenon lamp light. The light preferably contains a component (blue light) having a wavelength on the short wavelength side in the visible region.
Further, a gap may exist between the container and the lens, that is, lutein may not be sealed by the lens.

In addition, the light can be applied to a lens or lutein after passing through a filter that simulates the spectral transmittance of the crystalline lens.
In this case, the lens or lutein is irradiated with light simulating the state after passing through the lens, and the light that strikes the retina (fovea) can be simulated through the lens, and the retina (fovea of the fovea) ), The degree of deterioration corresponding to the degree of macular pigment deterioration can be measured, and the protective effect of the lens can be evaluated in consideration of the effect on the retina (the fovea).
A cataract pseudo-experience lens can be used as a filter that simulates the spectral transmittance of the crystalline lens. The filter described in the following document can also be used as the filter. That is, Yasuo Sakamoto, “Light transmission characteristics of crystalline lens”, Science of Vision, Vol. 15, No. 4, 1994, pp. 198-205.
The filter may be disposed between the light source and the lens, or may be disposed between the lens and lutein.

  Further, the degree of degradation of lutein can be measured by various methods. For the purpose of improving accuracy, the degree of degradation of lutein can be measured by a combination of the following methods.

  For example, based on the fact that lutein is a carotenoid (pigment) and a part of the group is decomposed, the color becomes lighter and eventually becomes transparent, so that a predetermined transparency is obtained after light irradiation. The time until it is exhibited (until the predetermined yellowness or less) is measured, and the shorter the time, the higher the degree of deterioration of lutein (the deterioration progresses faster).

Alternatively, it is possible to measure the degree of deterioration of lutein by irradiating the same light for the same time and comparing the transparency (yellowness) of lutein. In this case, the degree of degradation of lutein with respect to the light that does not pass through the lens (change in lutein transparency (yellowness) over time) can be used as a reference. In other words, a function of the time for the light that does not pass through the lens and the transparency of the lutein is obtained, and the light irradiation time when the lens does not pass is determined by applying the transparency of the lutein for the light that passes through the lens to the function. The light irradiation times can be appropriately compared and the degree of degradation of lutein can be measured.
The transparency of lutein can be measured, for example, by measuring the spectral transmittance distribution in the visible region and comparing it with the transmittance distribution when all are lutein (pure lutein). .
The yellowness of lutein can be grasped by, for example, the yellowness YI related to the XYZ color system. Here, the yellowness YI is represented by stimulation values X, Y, and Z in the XYZ color system, and YI = 100 (1.2769X−1.059Z) / Y. Stimulus values X, Y, and Z can be obtained by irradiating standard light such as a D65 light source.
Alternatively, the yellowness of lutein can be represented by b ^* of the L ^* a ^* b ^* color system (International Commission on Illumination CIE 1976). This is because the positive direction of L ^* a ^* b ^* color system b ^* indicates the yellow direction.
In addition, before shining light, the transparency (initial transparency) and yellowness (initial yellowness) of lutein can be measured and compared with the transparency after light irradiation. It becomes possible to measure more accurately and easily by comparing the two.

  In addition, since lutein (a part of the set) is no longer lutein when decomposed by light irradiation or the like, it becomes a substance that is an initial set of lutein only (or lutein having a predetermined initial deterioration level). On the other hand, if the amount of lutein in the substance after irradiation with light (or a decrease from the beginning of lutein) is measured by component analysis or the like, the degree of degradation of lutein can be measured. The greater the remaining amount of lutein after light irradiation for the same time (the smaller the amount of lutein decrease), the lower the degree of degradation of lutein.

Furthermore, the degree of degradation of lutein can also be grasped by measuring the antioxidant ability of lutein. The higher the anti-oxidation ability of lutein, the smaller the degree of deterioration of lutein, and the higher the anti-oxidation ability of lutein, the greater the degree of deterioration of lutein.
The antioxidant ability of lutein can be measured using a kit that measures the antioxidant ability of vitamins and the like. The kit contains a specific divalent metal ion to be mixed with a test object to be tested for antioxidation ability, for example, and the degree to which the metal ion is oxidized to a monovalent metal ion when mixed with the test object is colored. And the reduction ability of the test substance, that is, the antioxidant ability is measured.
If the degradation effect of lutein is measured by the anti-oxidation ability of lutein and the protective effect of the lens is evaluated, it becomes possible to evaluate the effect of reducing the oxidative stress related to the lens in a manner that is suitable for human eyes.
In addition, before shining light, the antioxidant ability (initial antioxidant ability) of lutein can be measured and compared with the antioxidant ability after light irradiation. By comparing the degree of degradation of lutein with the initial degree of degradation It becomes possible to measure more accurately and easily.

The lens capable of evaluating the protective effect (evaluation target, test lens) is preferably a spectacle lens (including sunglasses), but is not limited to this, and may be an intraocular lens, a welding shielding plate, or the like. There may be.
The curve value, power, material, Abbe number, etc. of the lens may be any. For example, even a flat lens that is not curved can be evaluated, and even a lens made of glass can be evaluated.
Furthermore, the color density of the lens may be anything, for example, lenses with density differences that are difficult to distinguish with the human eye, and the human eye almost recognizes the coloration. Although not possible, the lens may actually be slightly colored.

[Specific examples of new lens evaluation methods]
Next, a specific example of the evaluation method will be described. In addition, the said evaluation method is not limited to the following specific examples.

The protective effect was evaluated for the three types of lenses A to C each having a spectral transmittance distribution shown in FIG. Incidentally, none of the lenses A to C belong to the present invention (comparative example).
The lens A is a urethane resin spectacle lens having a cutoff wavelength in the vicinity of 400 nm (round lens before target processing, the same applies hereinafter). The transmittance of light on the shorter wavelength side than the cutoff wavelength is 0% (percent), and the transmittance of light on the longer wavelength side of the cutoff wavelength is about 90%.
The lens B has a long wavelength, in which an optical multilayer film is formed on the surface in order to cause a minimum point (approximately 20%) of the transmittance distribution to appear in the vicinity of 685 nm with respect to a lens having the same spectral transmittance distribution as the lens A. It is a spectacle lens that cuts the light on the side.
The lens C is a lens that is further colored yellow with respect to the same lens as the lens A, and has a cutoff wavelength near 450 nm.
All the lenses have the same curve.

In evaluating the protective effect, an evaluation sample containing lutein was prepared as described below.
That is, an aqueous solution of lutein-L8 (lutein (free) content 4.0% or more, lutein ester content 8.0% or more) manufactured by Oriza Oil Chemical Co., Ltd., which is an edible pigment containing only lutein as a pigment was prepared. The aqueous solution was prepared by dissolving 0.2 g (gram) of the evaluation sample (Lutein-L8) in a pure amount of 1000 g.
An equal amount (about 10 milliliters) of the aqueous solution was placed in three petri dishes L (see FIG. 2) having the same shape, and used as evaluation samples for each lens. Each petri dish L is a flat bottomed cylindrical container having a diameter smaller than the diameter of each lens A to C.
In addition, for the lutein (aqueous solution) in the petri dish L, the spectral transmittance distribution was measured (before xenon irradiation) before setting the light irradiation device described later. Here, the transmittance distribution in the wavelength region of 350 to 600 nm was measured.

Each lens A to C and each petri dish L were set in a light irradiation apparatus described below.
That is, Super Xenon Weather Meter SX2-75 manufactured by Suga Test Instruments Co., Ltd. having a 7.5 kW xenon lamp.
The light emitted from such a xenon lamp has a spectral intensity distribution similar to that of sunlight (simulated light of sunlight), and is exposed to sunlight for one day when irradiated in the apparatus for 2 hours. Irradiation equivalent to can be performed.
The light irradiation device was set in a state where the lenses A to C were covered one by one on each petri dish L (xenon lamp side) (see FIG. 2). The lenses A to C are all convex upward. A petri dish L was placed in a space surrounded by the lens A and the stage of the light irradiation device, and the same was applied to the lenses B and C.

Then, each of the light irradiation devices was irradiated with light for 2 hours, and immediately after that, the spectral transmittance distribution was measured for the lutein (aqueous solution) in the petri dish L (same as before the xenon irradiation).
FIG. 3 shows the spectral transmittance distribution of lutein before and after xenon irradiation.
In any of the luteins covered with the lenses A to C, the transmittance of lutein has increased in the wavelength region of about 350 to 530 nm from before xenon irradiation, and the lutein has faded and became colorless and has increased transparency and deteriorated. Appears.
Further, the lutein covered with the lens A (protected by A) and the lutein covered with the lens B (protected by B) have almost the same spectral transmittance distribution, and the degree of degradation of lutein is the same. From this result, it is possible to evaluate that the protective effects of the lenses A and B on the human eye are equivalent. Therefore, even if light is cut on the long wavelength side of the visible region (lens B), if the cut state of the light on the short wavelength side of the visible region is the same (lenses A and B), the effect of protecting human eyes It turns out that there is not much change.
Further, lutein covered with the lens C (protected by C) has a lower spectral transmittance distribution than the lenses A and B, and is closer to the spectral transmittance distribution before the xenon irradiation. That is, in the case of the lens C, an increase in lutein transmittance is suppressed compared to the case of the lenses A and B, and the degree of degradation of lutein is low. From this result, it can be evaluated that the protective effect of the lens C against the human eye is superior to the lenses A and B. Therefore, in the lens C, the fact that the short wavelength side in the visible region is cut (the transmittance in the vicinity of 400 to 450 nm is almost 0%) has the effect of protecting the human eye. It becomes possible to judge accurately (as for the human eye). Moreover, such an accurate judgment can be easily made by only preparing lutein, irradiating with light for several hours, and measuring the spectral transmittance distribution.

[Examples of the present invention]
Next, features of the spectacle lens according to the present invention (including evaluation of the protective effect against blue light by the above-described new evaluation method) will be described.

As a first embodiment of the spectacle lens according to the present invention, a lens D is shown in FIG. 4 showing the spectral transmittance distribution in the visible region and the vicinity thereof. In the spectral transmittance distribution of the lens D, the transmittance at a wavelength of 410 nm is less than 2%, and the transmittance at 440 nm is 85% or more. The luminous transmittance of the lens D is 85% or more (89%).
Here, the lens D is made of a resin that does not have an optical multilayer film such as an antireflection coating (not surface-treated only by the lens substrate), and is formed by polymerizing raw material monomers and the like as follows.
The raw material monomer is episulfide-based and is as follows. That is, 70.00 parts by weight (% by weight) of bis (β-epithiopropyl) sulfide, 18.82 parts by weight of bis (mercaptomethyl) -1,4-dithiane, and bis (isocyanatomethyl) -1,4 -It contains 4.18 parts by weight of dithian and 7.00 parts by weight of bis (isocyanatomethyl) bicyclo [2.2.1] heptane. In addition, these weight parts can be seen as weight%.
Further, an additive containing 0.05 parts by weight of a catalyst, 0.005 parts by weight of a release material, and 0.7 parts by weight of a UV absorber is added as an additive. The UV absorber is SEESORB703 manufactured by Cypro Kasei Co., Ltd., which is 2- (3-t-butyl-2-hydroxy-5-methylphenyl) -5-chloro-2H-benzotriazole.
The refractive index of the lens D is 1.70, the Abbe number is 36, and the thickness is 2 millimeters.

The lenses F1 to F4 (comparative examples) that do not belong to the present invention are also listed. The spectral transmittance distribution of the lenses F1 to F4 is also shown in FIG. The spectral transmittance distribution of the lens F1 rises from 0% to about 85% near 400 nm, becomes minimal (83%) at 450 nm, and maintains about 90% after about 480 nm. The spectral transmittance distribution of the lens F2 rises from about 0% to about 75% near 400 nm, becomes minimal (72%) at 450 nm, and maintains about 90% after about 480 nm. The spectral transmittance distribution of the lens F3 rises from 0% to about 62% near 400 nm, becomes minimal (59%) at 450 nm, and maintains about 90% after about 480 nm. The spectral transmittance distribution of the lens F4 rises from 0% to 53% at around 400 nm, becomes minimal (48%) at 450 nm, and maintains about 90% after around 480 nm. The lenses F1 to F4 are commercially available lenses for blue light-cut eyeglasses (so-called blue light compatible PC eyeglass lenses), which are slightly thin and yellowish in the lens F1 and become lenses F2 and F3. Accordingly, the yellow color becomes darker and the lens F4 is a considerably yellow lens.
The lenses F1 to F4 can be produced by dyeing a polyurethane resin with a dye prepared with a yellow disperse dye, and all have a refractive index of 1.60, an Abbe number of 42, and a specific gravity of 1.30.

FIG. 5 shows the results of evaluating the protection effect against blue light for the lenses D and F1 to F4, as in the lenses A to C. However, in FIG. 5, for each lens, the evaluation method related to the lens A or the like is repeated 12 times to obtain a spectral transmittance distribution of 12 luteins, and these are averaged.
In the lenses F1 to F4, the degree of cutting light of 400 to 450 nm is different, the degree of cutting of the lens F1 is low (the transmittance is relatively high), the transmittance of lutein after light irradiation is the highest, Degradation is greatest and protection effect is lowest. Next, the cut degree of the lens F2 is low, the lutein transmittance is the second largest increase, the degradation degree of lutein is the second largest, and the protective effect is the second lowest. Similarly, the degree of degradation of lutein related to the lens F3 is the third largest (the lens F3 has the second highest protection effect in the lenses F1 to F4), and the degree of degradation of lutein related to the lens F4 is the smallest (the lens F4 is The most protective effect).
The spectral transmittance distribution of lutein related to the lens D is the same as that of the lens F3, and it can be evaluated that the lens D has a protective effect equivalent to that of the lens F3. This evaluation was made in response to the human eye as for the human eye.
FIG. 6 is a graph showing each transmittance at 454 nm of lutein related to the lenses D and F1 to F4 in FIG. 5. In this graph, the lenses D and F3 have the same values. However, it can be evaluated that the lens D has a protective effect equivalent to that of the lens F3.

Further, regarding the lenses D and F1 to F4, the degree of coloring is observed. With respect to the colors of these lenses and the lens A of Example 1 (colorless and transparent appearance), the L ^* value, a ^* value, and b ^* value in the L ^* a ^* b ^* color system are measured with a measuring instrument. A color difference between A and the lenses D and F1 to F4 is obtained. Here, the L ^* value, a ^* value, and b ^* value are standard observations of the color matching function (see FIG. 7) assuming the age of 35 in view of JIS Z 8718 (a method for evaluating chromaticity such as observer conditions). Measure and calculate as a person. The color difference dE ^* = (L ^{* 2} + a ^{* 2} + b ^{* 2} ) ^1/2 .
These L ^* values, a ^* values, b ^* values and the color difference dE ^* from the lens A are shown in the following [Table 1]. Further, as a sense corresponding to the color difference dE ^* , there are those shown in NBS units established by the US National Bureau of Standards, as shown in [Table 2] below.

According to [Table 1], the color difference between the lens D and the transparent lens A is 5.21, which is about the degree of “conspicuous” in light of [Table 2]. The color difference between the lens D and the transparent lens A is slightly smaller than the color difference (6.02) associated with the lens F2. Further, the lens F3 having the same protective effect as the lens D has a color difference with the lens A of 11.09, which is a “large” feeling.
That is, the lens D has a protective effect equivalent to that of the lens F3, but has a coloring density that is less than the coloring density of the lens F3 (thinner than the lens F3) and is closer to the transparent lens A. This lens has a beautiful appearance and is easier to wear.

In addition, as mentioned in the above JIS Z 8718, the spectral sensitivity of the eye varies depending on the human age, and color matching functions for calculating L ^* , a ^* , and b ^* values can be considered according to age. It is. There are individual differences in the spectral sensitivity of the eye, and some humans with a standard spectral sensitivity that are relatively young (for example, 35 years old) but relatively old (for example, 60 years) can still be seen.
In the following [Table 3], L ^* value, a ^* value, b ^* value calculated using the color matching function at 60 years old (see FIG. 7) obtained based on JIS Z 8718, and the color difference dE with lens A ^* Indicates.

According to [Table 3], the color difference (3.07) between the lens D and the transparent lens A is “noticeable”, but the value is reduced compared to the case of [Table 1]. The value is very close to the minimum value of the range that is “prominently felt”. On the other hand, the color difference between the lenses F1 to F4 and the transparent lens A is larger than that in the case of [Table 1].
Therefore, it can be said that a 60-year-old standard observer seems to have a smaller color difference between the lens D and the transparent lens A than a 35-year-old standard observer. While having the same protective effect as F3, it can be said that the color becomes closer to the transparent lens A, and it is more beautiful and easy to wear.

Further, in FIG. 8, Table 1 (chromaticity calculation by 35-year-old color matching functions) and Table 3] ^{a *} value in (chromaticity calculation by color matching function 60 years old), the ^{b * values, L} * a A graph plotted in a ^* b ^* chromaticity diagram (a ^* b ^* plane, a ^* value is abscissa, b ^* value is ordinate). In addition, yellowness is so large that b ^* value is large in a positive direction.
According to FIG. 8, it can be seen that the yellowness of the lens D is the same as that of the lens F2 at the age of 35, and the yellowness of the lens D is the same as that of the lens F1 at the age of 60.
Therefore, also from FIG. 8, the lens D has a protective effect equivalent to that of the lens F <b> 3, and has a sufficiently reduced yellowness, and is more beautiful and easy to wear. It can be said.

Furthermore, the composition of the lens D is further mixed with a pigment or dye that absorbs light of the near-infrared wavelength (or an optical multilayer film that reflects near-infrared light is added), so that the wavelength range of 800 to 1500 nm is obtained. The average transmittance can be 80% or less. In this case, the eye can be protected from a temperature increase due to near-infrared rays, and a lens having a higher protection effect can be provided.
In addition, the color of the lens can be further increased by lowering the transmittance in the region other than the short wavelength side of the visible region by mixing a blue, purple, or red pigment or dye with the configuration of the lens D. It is possible to provide a lens that is colorless and more transparent and excellent in aesthetics.

FIG. 9 shows a second embodiment of the present invention in which a blue dye and a red dye are added to the lens D according to the first embodiment of the present invention, and an antireflection coating (optical multilayer film) is further provided on the surface. The spectral transmittance distribution of an Example (prototype lens) is shown.
In the prototype lens, 0.0003 parts by weight of a blue dye (TAP-5 manufactured by Yamada Chemical Co., Ltd.) and a red dye (YAZ28 manufactured by the same company) 0 are added to the raw material monomers and additives mentioned in Lens D. 0.0003 part by weight is added as an additive, and an antireflection coating is formed on the synthesized lens base.
The antireflection coating is an optical multilayer film having a five-layer structure in which a low refractive index layer (SiO ₂ ) and a high refractive index layer (ZrO ₂ ) are alternately deposited.
According to the prototype lens, the transmittance after about 440 nm is increased mainly by the antireflection coating (the lens D is about 92% to 97% compared to about 89%), and the transmission at 410 to 440 nm. The rate distribution becomes steeper, and the degree of coloring can be further reduced while enhancing the protective effect. This effect can be achieved by a general antireflection coating other than the above-described film configuration. Moreover, it is possible to adjust the color to be more colorless mainly by adding a dye, and it is possible to adjust the color to be closer to colorless by using other dyes and pigments. The prototype lens has a luminous transmittance of 93.5%, a transmittance at 410 nm of 1.9%, and a transmittance at 440 nm of 94%.
[Table 4] shows the color difference of the prototype lens (D + color adjustment + antireflection coating) from the lens A (in the case of a 35-year-old standard observer). The L ^* value, a ^* value, and b ^* value of the lens A are measured again.

According to [Table 4], it can be seen that the prototype lens has a color difference of 3.16 from the colorless and transparent lens A in the case of a 35-year-old standard observer. That is, it can be seen that the prototype lens has a color difference from the lens A that is more colorless than the lens D compared to the color difference 5.21 related to the lens D, and is approaching colorless.
And according to the result of the simulation in which the spectral transmittance distribution is slightly changed from the lens D or the prototype lens, the configuration of the present invention has a sufficient protective effect as with the lens D or the prototype lens, It is possible to provide a spectacle lens or the like in which yellowing is suppressed.

[Invention of a novel lens evaluation method]
The invention relating to the above-described lens evaluation method will be described.
(1) Light is applied in a state where the lens is put on a macular pigment outside the body, and the degree of deterioration of the macular pigment is measured. The lens evaluation method is characterized in that the protective effect of the lens is increased.
(2) The lens evaluation method according to (1), wherein the light is applied to the macular pigment through a filter that simulates a spectral transmittance of a crystalline lens.
(3) The degree of degradation of the macular pigment is measured by the transparency of the macular pigment. The greater the transparency, the greater the degradation level, and the smaller the transparency, the smaller the degradation level. The lens evaluation method according to (1) or (2) above.
(4) The transparency of the macular pigment is measured by the spectral transmittance distribution of the macular pigment. The greater the transmittance in the spectral transmittance distribution, the greater the transparency, and the smaller the transmittance in the spectral transmittance distribution. The method for evaluating a lens according to any one of (1) to (3) above, wherein the transparency is small.
(5) The degree of degradation of the macular pigment is measured by the yellowness of the macular pigment. The smaller the yellowness, the greater the degradation, and the greater the yellowness, the smaller the degradation. The method for evaluating a lens according to any one of (1) to (4) above, wherein:
(6) The degree of degradation of the macular pigment is measured by the antioxidant ability of the macular pigment. The smaller the antioxidant capacity, the larger the degree of degradation, and the larger the antioxidant capacity, the smaller the degree of degradation. The method for evaluating a lens according to any one of (1) to (5) above, characterized in that:
(7) The method for evaluating a lens according to any one of (1) to (6), wherein an initial deterioration degree of the macular pigment is measured before light is applied to the macular pigment.
(8) The lens evaluation method according to any one of (1) to (7) above, wherein the macular pigment is at least one of lutein and zeaxanthin.
(9) The lens evaluation method according to any one of (1) to (8) above, wherein the macular pigment is extracted from a plant.

Claims (4)

The transmittance of light with a wavelength of 410 nm is 5% or less,
The transmittance of light having a wavelength of 440 nm is 85% or more,
A spectacle lens having a luminous transmittance of 85% or more. The spectacle lens according to claim 1, further having an average transmittance of 80% or less at a wavelength of 800 to 1500 nm. The spectacle lens according to claim 1, further comprising at least one of a pigment or a dye that is at least one of red, blue, and purple. An eyeglass using the eyeglass lens according to any one of claims 1 to 3.

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