WO2024204838A1 - Red light irradiation device - Google Patents

Abstract

[Problem] To provide a red light irradiation device capable of effectively and efficiently irradiating red light having a wavelength within a range of 610 to 900 nm to eyes. [Solution] Provided is a red light irradiation device that is worn around eyeballs and used for the purpose of preventing myopia or inhibiting progression of myopia, the red light irradiation device comprising light sources that emit at least red light having a wavelength within a range of 610 to 900 nm. The light sources are disposed in positions where the red light is irradiated toward the eyeballs when the red light irradiation device is worn and the distance from the surfaces of the eyeballs is greater than 0 mm and less than or equal to 100 mm. The irradiance of the red light is within a range of 0.01 W/m²-100 W/m² on the surfaces of the eyeballs. Through this configuration, the problem described above is solved.

Description

Red light irradiation device

The present invention relates to a red light irradiation device that effectively and efficiently irradiates red light toward the eyes.

The effects of light on the human body have been studied from various perspectives in recent years, and reports based on new findings have been published. For example, it has been reported that exposure to sunlight improves circadian rhythms (Non-Patent Document 1), that light emitted from LED lighting and liquid crystal displays that use LEDs as backlights has a significant effect on the body and mind (Non-Patent Document 2), and that violet light prevents myopia and suppresses the onset of myopia (Patent Document 1). In particular, the present inventor has recently reported on the effects of violet light on myopia. For example, Patent Document 1 proposes that light of a specific wavelength has the effect of preventing or suppressing the progression of myopia, and in recent years, as the number of myopic people continues to increase worldwide, great expectations are being placed on this. The present inventor has also proposed a device that suppresses choroidal thinning by irradiating violet light with a wavelength in the range of 360 nm to 400 nm (Patent Document 2).

On the other hand, Patent Document 3 proposes a method for increasing the blood flow and metabolic rate of the fundus by irradiating the fundus through the pupil with red or near-infrared light of a certain wavelength range, a certain energy density range, and a certain irradiation time. According to this method, it is said that the product generated through the pupil can increase the blood flow and metabolic rate of the fundus tissue that reaches it, improve the effect of repairing damage to ocular tissue, and repair the remodeling of scleral fibroblasts and visual function cells.

Megumi Hatori, Kazuo Tsubota, Anti-Aging Medicine - Journal of the Japanese Society of Anti-Aging Medicine, Vol.11, No.3, 065(385)-072(392), (2015). Kazuo Tsubota, "Blue Light: A Threat to the Body Clock", Shueisha, published November 20, 2013.

WO2015/186723A1 JP 2022-49654 A U.S. Pat. No. 1,142,072

The object of the present invention is to provide a red light irradiation device that can effectively and efficiently irradiate red light toward the eyes.

The red light irradiation device according to the present invention has a light source that emits at least red light with a wavelength in the range of 610 to 900 nm, and is worn near the eyeball to be used for preventing myopia or inhibiting the progression of myopia, characterized in that the light source is disposed at a position where the red light is irradiated toward the eyeball when the red light irradiation device is worn and at a position more than 0 mm and not more than 100 mm from the surface of the eyeball, and the irradiance of the red light is within a range of 0.01 W/ ^m2 or more and 100 W/m2 or ^less on the surface of the eyeball.

According to this invention, red light emitted from a light source can be appropriately irradiated onto the eyeball. The light source emits at least light with a wavelength within the above range, and is positioned so that when worn, the light source irradiates red light toward the eyeball and is positioned at a position greater than 0 mm and less than 100 mm from the surface of the eyeball, so that the irradiated light can be delivered effectively to the eyeball. As a result, the power of the light source required to deliver light of sufficient irradiance to the eyeball can be made relatively small. This allows effective and efficient irradiation toward the eyeball, making the red light irradiation effect effective.

Such red light irradiation devices are devices that can be used in everyday life, and are not large irradiation devices used in medical settings. More specifically, they are devices that individuals can use in their daily lives, such as at home, at work, or at school, and therefore can be used by many people in their daily lives according to their individual lifestyles. As a specific example of its use, it is preferable for it to be used for preventing myopia or inhibiting the progression of myopia.

In the red light irradiation device according to the present invention, the irradiance can be set to a low irradiance within a range of 0.01 W/ ^m2 to 10 W/ ^m2 or within a range of 0.01 W/ ^m2 to 1 W/ ^m2 depending on the purpose of use. According to this invention, since the irradiance can be set within the low irradiance range, it can be used depending on the purpose of use. In particular, when used for long-term myopia prevention or myopia progression suppression, devices with different upper limits of irradiance are available, and the irradiance required by the user can be set.

In the red light irradiation device according to the present invention, the light source is preferably one or more LED light sources. According to this invention, LEDs have the property of spreading as they move, and are power-saving and have a long lifespan, making them superior to laser diodes in that they are preferably used for long-term myopia prevention or myopia progression inhibition applications.

The red light irradiation device according to the present invention can be configured as a glasses type, an ear hook type, or a goggle type. By using these types of red light irradiation devices, when worn, the device can be positioned so that red light is irradiated toward the eyeball and is located more than 0 mm and less than 100 mm from the surface of the eyeball.

When the red light irradiation device is in the form of glasses, it is preferable that the light sources are arranged in one or more locations selected from the rim, nose pad, and endpiece without obstructing the field of vision, in one or more numbers. By arranging them in such a location, the user can use the device without interfering with the field of vision, which is preferable, for example, for long-term use in preventing myopia or inhibiting the progression of myopia.

When the red light irradiation device is of the eyeglass type, it is provided with a transparent lens. Since it is provided with a transparent lens, it can be preferably used as an eyeglass type red light irradiation device that can be used daily. According to this invention, the user can use it as everyday nearsightedness glasses, etc., so it is preferable for long-term use, for example, for preventing myopia or inhibiting the progression of myopia.

If the red light irradiation device is in the form of glasses, it is preferable that it is glasses for children. According to this invention, it is preferable that it is used for preventing myopia or inhibiting the progression of myopia, which has been increasing in recent years, in children.

The red light irradiation device of the present invention allows the irradiated light to reach the eyeball appropriately, so the power of the light source required to deliver light of sufficient irradiance to the eyeball can be made relatively small. This allows effective and efficient irradiation toward the eyeball, making the red light irradiation effect effective.

FIG. 2 is a schematic diagram showing an example of a glasses-type red light irradiation device according to the present invention, in which a red light source is provided on the lower rim. FIG. 1 is a schematic diagram showing an example of a glasses-type red light irradiation device according to the present invention in which a red light source is provided in an endpiece. FIG. 2 is a schematic diagram showing an example of a glasses-type red light irradiation device according to the present invention, in which a red light source is provided on the upper rim. FIG. 2 is a schematic diagram showing a manner in which red light is irradiated toward the eye. FIG. 1 is a schematic diagram showing an example of an ear-hook type red light irradiation device. FIG. 1 is a schematic diagram showing an example of a goggle-type red light irradiation device used for pollen and dust prevention, work, sports, and for AR, VR, or MR in games. 1 is a graph showing the relationship between the spectral irradiance and wavelength of red light used in Experiment 1. FIG. 13 is a schematic diagram showing another example in which a red light source is installed in a glasses-type red light irradiation device. FIG. 13 is a schematic diagram showing yet another example in which a red light source is installed in a glasses-type red light irradiation device.

The red light irradiation device according to the present invention will be described below with reference to the drawings. As long as the gist of the present invention is included, the present invention is not limited to the following embodiments and examples, and can be modified in various ways.

[Red light irradiation device]
As shown in Figures 1 to 6, 8 and 9, a red light irradiation device 10 (10A, 10B, 10C) according to the present invention has a light source 11 that emits at least red light 13 with a wavelength in the range of 610 to 900 nm, and is a red light irradiation device that is worn near the eyeball 20 and used for preventing myopia or suppressing the progression of myopia, and the light source 11 is arranged at a position where the red light 13 is irradiated in the eyeball direction D when the red light irradiation device 10 is worn and at a position more than 0 mm and not more than 100 mm from the surface of the eyeball 20, and is configured so that the irradiance of the red light 13 is in the range of 0.01 W/ ^m2 or more and 100 W/ ^m2 or less on the surface of the eyeball 20.

As shown in FIG. 4, such a red light irradiation device 10 can appropriately irradiate the eyeball 20 with red light 13 emitted from the light source 11. The light source 11 emits at least red light 13 with a wavelength within the above range, and is positioned so that when worn, the light source 11 irradiates the red light 13 in the eyeball direction D and is located within a predetermined distance from the surface of the eyeball 20, so that the irradiated red light 13 can be effectively delivered to the eyeball 20. As a result, the power of the light source required to deliver red light 13 of sufficient irradiance to the eyeball 20 can be relatively small. This allows effective and efficient irradiation toward the eyeball 20, making the irradiation effect of the red light 13 effective.

Such a red light irradiation device 10 is a device that can be used in daily life, and is not a large irradiation device used in medical settings. More specifically, since it is a device that can be used by individuals in their daily lives at home, at work, at school, etc., many people can use it in their daily lives according to their individual lifestyles. As a specific example of its use, it is preferable that it be used for preventing myopia or inhibiting the progression of myopia.

[Each component]
Each component will be described in detail.

In the following embodiments, the symbol X is the left-right direction (horizontal direction) in the state where the eyeglass-type red light irradiation device (hereinafter referred to as "eyeglass-type device 10A") is worn, and the symbol Y is the up-down direction (vertical direction) in the state where the eyeglass-type device 10A is worn. In the following, as shown in Figures 4 and 5, "position A below the front of the eyeball" means a position below the imaginary line Z1 that extends horizontally in the front direction of the eyeball 20 when the body and head are facing directly forward and the eyeball is looking forward, and "position B from the front below the front to the side of the eyeball" means a position on the imaginary line Z2 that extends horizontally from position A in the left-right direction to the side at the above-mentioned "front below" position A. "Side position B of the eyeball" is slightly different from the above-mentioned "position B from the front below the front of the eyeball" and means a position on a virtual line that extends horizontally in the left-right direction to the side of the eyeball 20 (in other words, "directly across"). For the sake of convenience, the same symbol B as above is used for "lateral position B of the eyeball." Furthermore, when referring to "upper," "lower," "upper," and "lower," the vertical direction Y is used as the reference, and when referring to "horizontal," "right," "left," and "lateral," the horizontal direction X is used as the reference. Furthermore, the word "light" is used in the sense of electromagnetic waves, so replacing "light" with "electromagnetic waves" has the same meaning.

(Glasses-type red light irradiation device)
The eyeglasses-type device 10A is an irradiation device that has a light source 11 that emits at least red light 13 with a wavelength in the range of 610 to 900 nm and is worn near the eyeball, as shown in Figures 1 to 6. This eyeglasses-type device 10A is eyeglasses that can be used in daily life and work, and the basic structure of such eyeglasses-type device 10A is generally basically composed of a transparent lens 2, a rim 3 (a part that fixes the lens), a joint 4 (both ends of the eyeglasses that connect the rim 3 to the temple 6), a hinge 5 (an opening and closing part that connects the rim 3 and the temple 6), a temple 6 (a part that supports the eyeglasses), an end piece 7 (a part at the end of the temple 6 that rests on the ears), a nose pad 8 (a part that holds the eyeglasses by pinching them from both sides of the nose), and a bridge 9 (a part that connects the left and right lenses), as described in Figure 1. The shape of the eyeglass-type device 10A is not limited to these, and any of these parts may be omitted or the shape may vary in size depending on the fashion or individual eyeglass style, etc. For example, the eyeglass-type device 10A usually has a hinge 5, but if the protruding portion 3a is large as shown in Figure 1, it may be difficult to fold the temple 6 at the hinge 5, so the hinge 5 may not be provided.

There are special eyeglasses used only in treatment rooms in hospitals for eye treatment, such as closed goggle-type eyeglasses that prevent gaps between the eyeglasses and the face, and eyeglasses for treatment only for eye treatment. However, such conventional eyeglasses are used only in treatment rooms in hospitals, and are large and have a special structure, so they cannot be used daily at home, at work, or when going out. On the other hand, the eyeglasses-type device 10A of the present invention is preferably an open eyeglasses-type device 10A that is generally used and can be worn daily, as shown in Figures 1 to 3, 8, and 9, rather than special eyeglasses for treatment only for eye treatment. By applying the features of the present invention to an eyeglasses-type device 10A of such a general structure or a structure similar thereto, it can be used in various situations such as daily life and work, and can also be used as an eye treatment device in a medical setting. Therefore, whether or not a person wears glasses on a daily basis, the glasses can be used as a new medical device that allows eye treatment while going about their daily life or work, and more people can enjoy the benefits of the present invention (making the irradiation effect of red light 13 effective). They are particularly suitable as glasses for children (e.g., ages 6 to 15) who are prone to developing diseases such as myopia.

Lens 2 may be a glass lens or a plastic lens as long as it is a transparent lens. The word "transparent" is used to clarify that it does not impede vision, as with conventional glasses for specialized medical treatment or treatment. It is also to clarify that it can be used in daily life. It may also be a lens that can cut out desired wavelengths, or may be a lens that corrects myopia, hyperopia, astigmatism, etc., or may be simple glass without correction, or may be a colored lens like sunglasses. In addition, the glasses-type device 10A of the present invention has the light source 11 positioned so that the red light 13 emitted from the light source 11 is directly irradiated toward the eyeball 20, so that a sufficient field of vision can be ensured, just like glasses that can be used in daily life.

The materials of each part of the eyeglasses-type device 10A, such as the rim 3, end piece 4, hinge 5, temple 6, end piece 7, nose pad 8, etc., are not particularly limited and may be resin, metal, or other materials. Also, the eyeglasses may be made of different materials for each part. Resin materials are easy to mold and process, and are preferably used. They may be transparent (including colorless transparent or colored transparent), or colored opaque or translucent. The area of each of these parts varies depending on the design of the eyeglasses, so when applying the components of the present invention to such eyeglasses, the light source 11 can be provided in parts with ample installation area (such as the end piece 4 or temple 6) rather than the rim 3, which has a small installation area, and the eyeglasses as a whole can be slimmed down.

As shown in Figs. 1 to 3, 8, and 9, this eyeglasses-type device 10A is configured by attaching the light source 11 to the components of eyeglasses used daily and integrating them. On the other hand, it is also possible to use an application form in which the components of eyeglasses used daily are left as they are and the light source 11 is attached to the eyeglasses as a removable part (also called an attachment part). Specifically, for example, it may be an attachment eyeglasses-type device (not shown) that can be attached and detached to eyeglasses used normally, or it may be an ear-hook type red light irradiation device (hereinafter referred to as "ear-hook type device 10B") shown in Fig. 5, in which only the light source 11 provided at the tip of the ear-hook type red light irradiation device (hereinafter referred to as "ear-hook type device 10B") is attached as a removable part to the lower rim 3b or the side rim 3d of eyeglasses used normally (not shown). In this way, when it is desired to irradiate the eyeball 20 with red light 13, it can be easily attached and detached to eyeglasses used normally, and the same effect as the eyeglasses-type device 10A can be achieved. The term "attachment" is used to mean something that can be detachably attached to glasses that are normally worn.

(light source)
The light source 11 is disposed at a position where the red light 13 is irradiated in the eyeball direction D when the eyeglass-type device 10A is worn by a person. The position of the light source 11 is not particularly limited, but it is preferable that the light source 11 is disposed at one or more locations selected from the rim 3, the nose pad 8, and the endpiece 4 without blocking the field of view, depending on the form of the eyeglass-type device 10A. By providing the light source 11 at such a position, the user can use the device without interfering with the field of view, which is preferable, for example, for long-term use in preventing myopia or inhibiting the progression of myopia. In addition, as shown in FIG. 4, the light can be irradiated with directionality in the direction D of the eyeball 20, so that the light can be delivered directly, effectively, and efficiently to the eyeball without being blocked by the eyelid.

1, the light source 11 is provided on the lower rim 3b, and in the example of FIG. 2, the light source 11 is provided at two locations on each of the right and left eye sides (total of four locations) with a gap between them. In the example of FIG. 2, the light source 11 is provided on the endpiece 4. In the example of FIG. 3, the light source 11 is provided on the upper rim 3c. In the example of FIG. 8, the light source 11 is provided on the upper rim 3c. In the example of FIG. 9, the light source 11 is provided on the nose pad 8. The nose pad 8 can be said to be easy to wear the light source 11 and to easily irradiate the red light 13 in the eyeball direction D. In particular, the nose pad 8 in the form shown in FIG. 9 is slightly thicker than a thin rim, so the light source 11 can be installed in an inconspicuous and unnoticeable manner, and can be said to be a practical installation position for the eyeglass-type device 10A used daily. In addition, by providing the light source 11 in a location with a large installation area (such as the endpiece 4 or temple 6, but preferably the endpiece 4 shown in FIG. 2) rather than the rim 3, which has a small installation area, the entire eyeglasses can be slimmed down. In this way, the light source 11 may be provided at one or more of the lower rim 3b, upper rim 3c, side rim 3d, inner rim 3e, nose pad 8, or end piece 4.

The red light 13 emitted from the light source 11 is light with a wavelength in the range of 610 to 900 nm. The red light 13 with a wavelength in this range can be irradiated onto the eyeball 20, making the irradiation effect of the red light 13 effective. "Light with a wavelength in the range of 610 to 900 nm" may be light with a wavelength in the range of 610 to 900 nm, and may be, for example, light of about 610 to 750 nm, light of about 630 to 700 nm, light of about 630 to 660 nm, or light of 750 to 900 nm.

Furthermore, since such red light 13 needs to contain at least light with a wavelength in the range of 610 to 900 nm, it may be light with an optical spectrum that has a peak in the wavelength range of 610 to 900 nm, for example, or light with an optical spectrum that does not have a peak in the wavelength range of 610 to 900 nm.

The red light 13 may only be light with a wavelength in the range of 610 to 900 nm. In this case, it may contain a small amount of light outside the wavelength range of 610 to 900 nm (light with a wavelength less than 610 nm or light longer than 900 nm). "A small amount" can refer to a state in which the light is contained as noise that is significantly smaller than the irradiance described below, or a state in which the light is contained slightly as part of the base of the optical spectrum. There is no particular limit to the extent to which the light is contained, but it is light that does not contribute to preventing myopia (suppressing its occurrence) or inhibiting the progression of myopia, and can be said to be less than 10% of the amount of light in the range of 610 to 900 nm.

In the present invention, when the light source 11 is attached at a predetermined position 100 mm or less from the surface of the eyeball 20, the irradiance on the surface of the eyeball 20 is 0.01 W/m ² or more, preferably 0.02 W/m 2 or more, more preferably 0.25 W/m ² or more, and even more preferably 0.5 W/m ² or more, as an integrated value in the wavelength range of 610 to 900 nm. Also, the integrated value in the wavelength range of 610 to 900 nm is 100 W/m ² or ^less , preferably 10 W/m ² or less, and more preferably 1 W/m ² or less. By irradiating the surface of the eye with red light 13 of such irradiance, the unique action of the red light 13 can be made effective. Note that 100 W/m ² is converted to 0.01 W/cm ² .

The irradiance can be set to a low level within the range of 0.01 W/ ^m2 to 10 W/ ^m2 , or 0.01 W/ ^m2 to 1 W/ ^m2 . Since the irradiance can be set to such a low level, it can be used according to the intended purpose. In particular, when the device is used for long-term myopia prevention or myopia progression inhibition, devices with different upper limits for the irradiance are available, and the irradiance required by the user can be set.

As the light source 11 with such irradiance, a commercially available LED or the like, as exemplified in FIG. 7, can be selected and used. In addition, the magnitude and wavelength range of the irradiance can be controlled by using a filter or the like that can control light transmittance. The spectral irradiance can be measured by a spectroscope, and the integrated value (irradiance) can be calculated by integrating the spectral irradiance in the wavelength range in which it is desired to find it. The spectral irradiance is measured as a value on the surface of the eyeball 20 when the eyeglass-type device 10A is worn. Therefore, as described below, the light source 11 worn on the eyeglass-type device 10A is positioned at a position between 0 mm and 100 mm from the surface of the eyeball 20, and the evaluation is performed at the position where the red light 13 from the light source 11 positioned within that range reaches the position of the eyeball 20.

(Wavelength of Light)
The red light 13 emitted from the light source 11 only needs to have a wavelength of at least 610 to 900 nm, so it may be only light with a wavelength of 610 to 900 nm, or may include light in other wavelength ranges. In the case of only light with a wavelength of 610 to 900 nm, an LED light source that emits only light in that range may be used, or a filter (light absorption filter) that does not transmit light other than light with a wavelength of 610 to 900 nm from light including light in other wavelength ranges may be used. The light source 11 is preferably an LED light source, and one or more such LED light sources can be used for installation. LEDs have the property of spreading while traveling, are power-saving, and have a long life, so they are superior to laser diodes in that they are preferably used for long-term myopia prevention applications or myopia progression suppression applications.

The light source 11 may emit one or more types of light selected from near-infrared light and far-infrared light other than red light, or may further include another light source that emits one or more types of light selected from near-infrared light and far-infrared light. Near-infrared light is light with a wavelength of about 900 nm to about 3000 to 4000 nm, and far-infrared light is light with a wavelength of more than that but not exceeding 1000 μm. In the field of chemical analysis, the concepts of mid-infrared light and ultra-far-infrared light are further added, and near-infrared light is light with a wavelength of about 900 nm to about 1500 nm, mid-infrared light is light with a wavelength of about 1500 nm to about 5600 nm, far-infrared light is light with a wavelength of about 5600 nm to about 25000 nm, and ultra-far-infrared light is light with a wavelength of about 25000 nm to about 1000 μm. Furthermore, for example, the light source 11 may further emit white light as necessary, or may further include another light source that emits white light. Furthermore, by also including a light source that emits violet light in the range of 360 to 400 nm, which is effective in preventing myopia or inhibiting the progression of myopia as proposed by the present inventor in Patent Document 1, the effect of preventing myopia or inhibiting the progression of myopia can be further enhanced.

(Distance from light source to eyeball)
In the present invention, it is preferable that the light source 11 attached to the eyeglass-type device 10A is disposed at a position more than 0 mm and not more than 100 mm from the surface of the eyeball 20. More than 0 mm from the surface of the eyeball 20 refers to, for example, a case where the light source 11 does not directly contact the eyeball 20. By disposing the light source 11 at such a position, it is possible to accurately, effectively, and efficiently irradiate the light toward the eyeball 20, and the action of the irradiated light can be made effective. The reason why the light source 11 is disposed at a position more than 100 mm away from the surface of the eyeball 20 is that the light source 11 is separated from the face or head, which reduces the accuracy of irradiation of the eyeball and may be a hindrance, and further reduces the range of selection of the light source 11. In addition, by disposing the light source 11 at a position more than 100 mm away from the surface of the eyeball 20, the irradiated light reaches the eyeball appropriately. As a result, the power of the light source 11 required to deliver light of a necessary and sufficient irradiance to the eyeball can be relatively small. This allows the irradiation device to be a power-saving device. In the eyeglass-type device 10A and the goggle-type red light irradiation device (hereinafter referred to as "goggle-type device 10C"), the distance from the surface of the eyeball 20 to the light source 11 is naturally 50 mm or less (actually 30 mm or less), so that the accuracy of irradiation onto the eyeball 20 is high and the irradiated light reaches the eyeball 20 appropriately.

(others)
The light source 11 may be attached to each type of red light irradiation device 10 (10A, 10B, 10C) with an adhesive, or may be attached mechanically with a screw or a crimping tool. A power source (not shown) for supplying power to the light source 11 may be a battery embedded or attached to each type of red light irradiation device 10 (10A, 10B, 10C), or may be a cable running to a battery attached in another position. If the light source 11 is not movable in one place, it may be connected to a household power source or the like.

Furthermore, the light source 11 may be equipped with a manual on/off switch, a controller, an on/off timer, etc. Examples of the controller include functions such as varying the irradiance and adjusting the angle of irradiation to the eyeball. Examples of the on/off timer include a timer that can set the irradiance time of the light. Such switches, controllers, timers, etc. may be provided integrally with each form of the red light irradiation device 10 (10A, 10B, 10C) or may be separate components.

Each type of red light irradiation device 10 (10A, 10B, 10C) may be provided with a light sensor, a temperature sensor, a humidity sensor, etc. The mounting position is not particularly limited, but it is preferable to select a position according to the type of sensor.

(Control device)
The control device 12 is provided in each of the red light irradiation devices 10 (10A, 10B, 10C) as necessary. The control device 12 controls the output, irradiation time, irradiation interval, etc. of the light source 11. By controlling with the control device 12, the required amount of red light 13 can be irradiated toward the eyeball 20. The control device 12 is a control circuit that has an electric circuit and controls the light source 11 based on the power supplied from the power source, and can be arbitrarily controlled by the voltage and current controlled by the electric circuit. The power source may be a small storage battery provided in the glasses (for example, the temple 6, etc.), or may be connected to the glasses by an electric wire to supply power. The control may be automatic or manual. In the case of manual control, it may be a means of pressing multiple switches that output in stages.

The control device 12 may be provided at any position in each form of the red light irradiation device 10 (10A, 10B, 10C). If each form of the red light irradiation device 10 (10A, 10B, 10C) has a wired communication element that controls the light source 11 by wire, the control device 12 may be preferably provided at a location other than the rim 3 (for example, the temple 6, etc.), or may be connected by wire and attached to a pocket, the body, or a part of clothing. Furthermore, if the eyeglass-type device 10A has a wireless communication element that wirelessly controls the light source 11, the control device 12 may be provided somewhere other than the eyeglasses. Examples of somewhere other than the eyeglasses include a case where a control application software (also referred to as the control device 12 in this application) is installed on a mobile terminal such as a smartphone, and the control is performed by running the application software.

When the control device 12 controls the light source 11, a specific example of the control device 12 is preferably one that can be used for ON/OFF control, such as increasing the output for five minutes during work and then decreasing it, or setting a timer to output for 10 minutes and then turning it off. A manual switch that manually turns the red light 13 on and off is low cost, has a simple structure, and is convenient. The red light 13 may be irradiated for a long period of time, such as several minutes to several hours (e.g., one to twelve hours) per day, for example, and may be continued for a long period of several months, irradiating the eye 20 with low irradiance red light 13 over a long period of time. By irradiating in a way that is desirable for each user, it is possible to gradually cure eye diseases over a long period of time, maintain eye health, and suppress the progression of myopia.

[Other forms of red light irradiation devices]
Although the glasses-type device 10A has been described above, here, an ear-hook type device 10B shown in Fig. 5 and a goggle type device 10C for functional, AR, VR and MR use shown in Fig. 6 will be described. Note that an in-eye cover type red light irradiating device (not shown) will not be described, but is similar to the other red light irradiating devices 10 (10A, 10B, 10C).

(Ear-hook type red light irradiation device)
5 shows a representative form of the ear-hook type device 10B. The ear-hook type device 10B can be used as a simpler red light irradiation device 10. Reference numeral 41 denotes an ear-hook arm, the tip of which is attached with a light source 11, and the rear end of which is designed to be stably hung on the ear. This ear-hook type device 10B also has the same components as the eyeglass type device 10A. In particular, the direction and position of the light source 11 are also similar, and it is desirable to provide the light source 11 in a direction and position suitable for irradiating the eyeball 20 with red light 13.

(Goggle-type red light irradiation device)
FIG. 6 shows a representative form of the goggle-type device 10C. The goggle-type device 10C can be used for pollen and dust prevention, for work, for sports such as skiing, and for AR, VR, or MR in games. Unlike the see-through AR and MR, the VR goggles have a closed front with no visibility, but all of the goggle-type devices 10C are used with the eyes open. The goggle-type device 10C has the same components as the eyeglass-type device 10A. In particular, the direction and position of the light source 11 are also the same, and it is desirable to provide the light source 11 in a direction and position suitable for irradiating the eyeball 20 with red light 13.

(Light source installation position)
The installation position of the light source 11 will be described with reference to Fig. 5. In any of the above-mentioned forms of the red light irradiation device 1 (10A to 10C), the light source 11 is provided at position A below the front of the eyeball 20, at position B to the side of the front below the eyeball 20, or at position B to the side of each of the eyeballs 20, and it is desirable that the distance from the eyeball 20 at any of positions A and B is more than 0 mm and 100 mm or less. Note that the position is not limited to below or to the side, and may be above or diagonally above.

"Position A below the front of the eyeball" refers to a position below an imaginary line Z1 that extends horizontally in the direction of the eyeball 20 when the body and head are facing forward and the eyeball 20 is looking forward, preferably a position that is more than 10 mm and less than 60 mm away from the eyeball 20 in a direction that forms an angle θ1 of 5° to 45° downward from the horizontally extending imaginary line Z1. Also, "position B to the side from the front below the front of the eyeball" refers to a position on an imaginary line Z2 that extends horizontally to the left and right from position A at the "front below" position A described above, preferably a position on an imaginary line Z2 that extends horizontally to the left and right from position A in a direction that forms an angle θ1 of 5° to 45° downward from the virtual line Z1, and a position on the virtual line Z2 that is more than 10 mm and less than 60 mm away from the eyeball 20.

Furthermore, "a lateral position of each eyeball" refers to a lateral position directly beside the eyeball 20, which is slightly different from the above-mentioned "lateral position B from the lower front of the eyeball" and refers to a position on an imaginary line extending horizontally in the left-right direction (in other words, "directly to the side") of the eyeball 20. Specifically, in the case of the eyeglass-type device 10A, it is a position on the endpiece or a lateral rim on the endpiece side, at a distance of more than 0 mm and no more than 100 mm from the eyeball 20.

By providing the light source 11 at position A below the front of the eyeball 20, at position B to the side of the front below the eyeball 20, or at a position to the side of each of the eyeballs 20, the light source 11 can be directed toward the eyeball 20 with good directionality. Furthermore, by positioning the light source 11 at a distance from the eyeball 20 that is more than 0 mm and not more than 100 mm, the light emitted from the light source 11 can be emitted with directionality toward the eyeball and can be delivered directly, effectively, and efficiently to the eyeball without being blocked by the eyelid. Note that as long as the light source 11 can be directed toward the eyeball 20 with good directionality, the position of the light source 11 is not limited to below or to the side, but may be toward the center of the nose pad 8 or inner rim 3e, above the rim, or diagonally upward.

As exemplified by the above-mentioned various forms of red light irradiation device 10 (10A to 10C), the red light irradiation device 10 of the present invention can be various types of devices and can be used as a new device that can be worn during daily life, work, or entertainment. Among these, in the case of the glasses-type device 10A in which a light source is installed in glasses that are used daily, the glasses themselves for myopia, hyperopia, etc. can be used as the red light irradiation device 10. In the case of an attachment glasses-type device (not shown) that can be attached to glasses that are used daily, it can be separate from the glasses that are used daily, and can be worn as attachment glasses only when it is desired to irradiate red light 13. In addition, the goggle-type device 10C for functional use, AR use, VR use, or MR use, and the front-of-eye cover type device (not shown) can be worn while using it for, for example, pollen or dust prevention, work, sports, games, IT work, etc. In addition, the ear-hook type device 10B and the front-of-eye cover type device can be worn as a device with a simple structure that is easy to put on and take off.

[Experiment 1]
Three LEDs (L850-40M00: AlGaAs LED, manufactured by epitex) with a peak wavelength of 850 nm in the spectrum shown in FIG. 7 were used and attached to the upper part of the eyeglass frame in the manner shown in FIG. 3. The three LEDs were connected in series so that the passing current value was 75 mA. The spectral irradiance on the surface of the mannequin's eye was measured. The irradiance in the 700-1000 nm range was 132 W/m ^2. Note that the IEC62471 safety standard is evaluated in the 780-3500 nm range, so the integral from 780 to 1000 nm is 131 W/m ^2. The IEC safety condition is max 2 W/m ² , so in this experiment, it exceeded 30%. This can be solved by reducing the number of LEDs or using them at a lower power.

[Evaluation and Consideration of Experiment 1]
The output power of three 850 nm LEDs was 132 W/m ² (=0.0132 W/cm ² ) per unit area (measured integral wavelength range was 700-1000 nm). The output energy per unit area mentioned in Patent Document 3 (US Pat. No. 1,142,072) is 0.5-25 J/cm ² or 0.5-15 J/cm ² , and the time is 150-210 s or 180 s. Here, if we calculate in a typical case of 15 J/cm ² for 180 s, we get 15/180 = 0.0833 W/cm ^2. Compared to the power of the above experimental results, this is 0.0833/0.0132 = 6.3 times larger. In Patent Document 3, the minimum combination is 0.5 J/ ^cm2 and 210 s, which is 0.5/210 = 0.0024 W/ ^cm2 , which is smaller than the power of the above experimental result, and is 0.0132/0.0024 = 5.5 times. In other words, the three 850 nm LED units in the above experiment can output a part of the power required from the combination of energy and irradiation time specified in Patent Document 3, and it is also easy to reduce the power to 0.01 W/ ^cm2 or less by powering down the unit for safety reasons. It can be seen that the power required from the combination of energy and irradiation time specified in Patent Document 3 exceeds the safety conditions of the IEC in part.

The three 850 nm LED units used in the above experiment consisted of three LEDs connected in series and one 5.1 Ω resistor connected in series. 5 V was applied to all of them, and a current of 75 mA was flowing (total power: 5 V x 0.075 A = 0.375 W). The input power of the unit in the above experiment, 0.375 W, is 1/80 of the value of 30 W (24 VDC, 1.25 A) given in the device in Patent Document 3 (Eyerising International's device manual (see p. 20)).

[Experiment 2]
In Experiment 1, the measured irradiance in the 700-1000 nm range was as high as 132 W/ ^m2 , so in Experiment 2, the output was lowered and the measured irradiance in the 700-1000 nm range was adjusted to 100 W/ ^m2 . Such irradiance allows the output power of the LED to be reduced, so the power of the light source 11 can be reduced, making it preferable for the eyeglass-type red light irradiation device 10 that can be used daily and a power-saving irradiation device.

[Experiment 3]
In this experiment 3, the output was further reduced, and the measured irradiance in the 700-1000 nm range was adjusted to 10 W/ ^m2 . Such a low irradiance can significantly reduce the output power of the LED, and therefore the power of the light source 11 can be further reduced, making it preferable as a glasses-type red light irradiating device 10 that can be used daily for long periods of time and can be a more power-saving irradiating device.

[Experiment 4]
In this experiment 4, the output was further reduced, and the measured irradiance in the 700-1000 nm range was adjusted to 1 W/ ^m2 . Such a low irradiance can significantly reduce the output power of the LED, and therefore the power of the light source 11 can be further reduced, making it preferable as a glasses-type red light irradiating device 10 that can be used daily for long periods of time, and can be a more power-saving irradiating device.

As described above, the red light irradiation device 10 according to the present invention is provided with a light source 11 that emits red light 13 with low irradiance, so the power of the light source required to deliver the light to the eyeball 20 can be reduced, making it preferable as a power-saving glasses-type red light irradiation device 10 that can be used for long periods of time and can be used daily. Such a glasses-type device 10A is effective in inhibiting the progression of myopia (axial myopia), and can be preferably used as a glasses-type device 10A for inhibiting the progression of vision (axial myopia).

LIST OF SYMBOLS 1 Glasses 2 Lens 3 Rim 3a Projecting portion 3b Lower rim 3c Upper rim 3d Side rim 3e Inner rim 4 End piece 5 Hinge 6 Temple 7 End piece 8 Nose pad 9 Bridge 10 Red light emitting device 10A Glasses-type device 10B Ear-hook type device 10C Goggle-type device 11 Light source 12 Control device 13 Red light 14 Sensor 14a Red light beam 20 Eyeball 31 Fixed part to glasses for normal use 41 Ear-hook arm A Position below the front of each eyeball B Position below the front of each eyeball to the side, position to the side of each eyeball C Virtual line when viewed from the front D Direction from light source to eyeball L Distance from light source to eyeball X Left-right direction (horizontal direction)
Y Up/Down (Vertical)
Z1: A virtual line extending horizontally in the front direction Z2: A virtual line extending horizontally in the left-right direction θ1: Angle downward from the horizontal coordinate axis

Claims (7)

A red light irradiation device having a light source that emits at least red light with a wavelength in the range of 610 to 900 nm, and worn near the eyeball to be used for preventing myopia or inhibiting the progression of myopia, characterized in that the light source is disposed at a position where the red light is irradiated toward the eyeball when the red light irradiation device is worn and at a position that is more than 0 mm and not more than 100 mm from the surface of the eyeball, and the irradiance of the red light is within a range of 0.01 W/ ^m2 or more and 100 W/m2 or ^less on the surface of the eyeball. 2. The red light irradiation device according to claim 1, wherein the irradiance is in the range of 0.01 W/ ^m2 to 10 W/ ^m2 , or in the range of 0.01 W/ ^m2 to 1 W/ ^m2 . The red light irradiation device according to claim 1 or 2, wherein the light source is one or more LED light sources. The red light irradiation device according to claim 1 or 2, wherein the red light irradiation device is of a glasses type, an ear hook type, or a goggle type. The red light irradiation device according to claim 1 or 2, wherein the red light irradiation device is in the form of glasses, and the light sources are arranged in one or more locations selected from the rim, nose pad, and end piece without obstructing the field of view, in one or more units. The red light irradiation device is of a glasses type and has a transparent lens. The red light irradiation device according to claim 1 or 2, which has a transparent lens. 3. The red light irradiating device according to claim 1, wherein the red light irradiating device is in the form of glasses and is glasses for children.

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