Light radiation device and light radiation system

Abstract

[Problem] To appropriately radiate light at an optimal radiance. [Solution] A light radiation device comprising: a first measurement unit that measures the pupil diameter of a subject; a control unit that, on the basis of the pupil diameter measured by the first measurement unit, controls the radiance of light irradiating the eye of the subject; and a light source that radiates light at the radiance resulting from the control by the control unit.

Description

Light irradiation device and light irradiation system

[0001] The present disclosure relates to a light irradiation device and a light irradiation system.

[0002] Devices that suppress myopia by irradiating light onto the human eye have been proposed (see Non-Patent Document 1, Patent Document 1, and Non-Patent Document 2). The existing technology described in Non-Patent Document 1 reports that by irradiating the eyes with red laser light having a wavelength of 650 nm for three minutes twice a day, progression of myopia was suppressed in a comparison between an irradiated group of 119 people aged 8 to 13 and a non-irradiated group of 145 people. Specifically, it was reported that refraction was suppressed by 77.6% and axial length by 69.4%.

[0003] In existing technology, a stationary device for myopia suppression is installed in each subject's home, and the subject uses this device to irradiate their eyes with red laser light twice a day.

[0004] Non-Patent Document 1 uses red laser light, but Patent Document 1 states that it can be used in the wavelength range up to near-infrared (up to 1000 nm). Although the detailed mechanism is unknown, it is said that light irradiation increases retinal blood flow, strengthening the choroid and sclera, thereby suppressing enlargement of the eye and slowing the progression of myopia.

[0005] U.S. Patent Publication No. 20210402205A1

[0006] Y. Jiang, et al., Ophthalmology 129, pp.509-519, 2022. H. Liu, et al., JAMA Ophthalmol. 141, pp.693-695, 2023.

[0007] With existing technology, the amount of light irradiated onto the subject is always set to a constant value (for example, 0.29 mW). This amount of light irradiated onto the subject is 2.28 mW / cm2 for a pupil diameter of 4 mm. ２ This means that the amount of light irradiated is too great, and so it cannot be used on people with a pupil diameter of 4 mm or more. However, existing technology uses pupil diameter measured in a hospital as a standard, and does not actually measure pupil diameter when irradiating light. This means that there is a risk of irradiating light on people who should not be irradiated with light.

[0008] In fact, some subjects exposed to light using existing technology have complained of photophobia or temporary afterimages, and recently, cases of retinal damage resulting in the disruption of the ellipsoid zone have been reported.

[0009] Furthermore, with existing technology, subjects must visit a hospital for testing to learn about the effects of light irradiation on the progression or prevention of myopia, which places a heavy burden on the subjects and may result in excessive light irradiation to the eyes without confirming the effects of light irradiation on the progression or prevention of myopia over a long period of time.

[0010] Furthermore, existing devices require the subject to enter an ID and password before light irradiation, but since anyone who knows the ID and password can use the device, the identity authentication mechanism is incomplete. Furthermore, existing devices cannot determine whether the subject's eye is ready to be irradiated with light, nor can they determine whether light irradiation has been properly performed on the subject's eye.

[0011] Therefore, the present disclosure provides a light irradiation device and a light irradiation system that can appropriately irradiate light with an optimum light irradiation amount.

[0012] In order to solve the above problems, the present disclosure provides a light irradiation device comprising: a first measurement unit that measures the pupil diameter of a subject; a control unit that controls the light irradiation amount of light to be irradiated onto the eye of the subject based on the pupil diameter measured by the first measurement unit; and a light source that irradiates light with the light irradiation amount controlled by the control unit.

[0013] The device may include a second measurement unit that measures the condition of the subject's eye, and a first judgment unit that judges whether or not to irradiate light onto the subject's eye based on the condition of the subject's eye measured by the second measurement unit, and the control unit may decide whether or not to irradiate light onto the subject's eye based on the judgment result of the first judgment unit.

[0014] The second measurement unit may irradiate light onto the subject's retina and receive reflected light from the retina, and the first determination unit may determine whether or not to irradiate light onto the subject's eye based on a tomographic image of the retina generated based on the measurement results of the second measurement unit.

[0015] The device may further include a third measurement unit that measures the axial length of the subject's eye, and a confirmation unit that confirms the progression or suppression status of the subject's myopia based on the axial length measured by the third measurement unit.

[0016] The third measurement unit may measure the axial length based on the results of irradiating light onto the cornea of ​​the subject and receiving reflected light from the cornea, and irradiating light onto the retina of the subject and receiving reflected light from the retina.

[0017] The third measurement unit may include a first sensor that measures the axial length of the subject's eye and measures the condition of the subject's eye.

[0018] The third measurement unit may include a first sensor that measures the axial length of the subject's eye, separate from a sensor that measures the eye condition of the subject.

[0019] The device may further include a fourth measurement unit that measures an iris pattern of the subject, and an authentication unit that authenticates the subject based on the iris pattern measured by the fourth measurement unit.

[0020] The present invention may further include a fifth measurement unit that measures the line of sight of the subject, and a second determination unit that determines whether or not light is irradiated onto the eye of the subject based on the line of sight measured by the fifth measurement unit.

[0021] The device may also include an adjustment unit that adjusts the direction of light irradiation from the light source or prompts the subject to adjust the position of their eyes when the second judgment unit determines that light is not being irradiated onto the subject's eyes.

[0022] The fifth measurement unit may include a sensor that measures the line of sight of the subject and measures at least one of a pupil diameter or an iris pattern of the subject.

[0023] The fifth measurement unit may include a second sensor that detects the line of sight of the subject, separate from a sensor that measures at least one of a pupil diameter or an iris pattern of the subject.

[0024] The fourth measurement unit may measure the pattern of the iris of the subject and also measure the diameter of the pupil of the subject, or may have a third sensor that measures the pattern of the iris of the subject separately from the sensor that measures the diameter of the pupil of the subject.

[0025] The apparatus may further include a communication unit that transmits measurement data of the subject including the pupil diameter measured by the first measurement unit.

[0026] The device may include a stationary or portable housing that houses the first measurement unit and the control unit.

[0027] The housing may be a housing for binoculars, an HMD device, or an eyewear device.

[0028] The light irradiated onto the subject's eye may be light in the wavelength range from red light to near infrared light.

[0029] A light irradiation system is provided, comprising: a light irradiation device that irradiates light of a predetermined wavelength onto the eye of a subject; and a management device that manages the light irradiation conditions under which the light irradiation device irradiates, wherein the light irradiation device has a first measurement unit that measures the pupil diameter of the subject; a second measurement unit that measures the condition of the eye of the subject; and a control unit that controls the amount of light irradiation to be irradiated onto the eye of the subject based on the pupil diameter measured by the first measurement unit; and the management device manages the light irradiation conditions that are set based on the condition of the eye of the subject measured by the second measurement unit.

[0030] The light irradiation conditions managed by the management device may include at least one of whether or not to irradiate light onto the subject's eye, the frequency at which light is irradiated onto the subject's eye, and the amount of light irradiated onto the subject's eye.

[0031] 1 is a block diagram showing a schematic configuration of a light irradiation device according to a first embodiment. FIG. 2 is a block diagram showing a schematic configuration of a light irradiation device according to a first modified example of the first embodiment. FIG. 3 is a flowchart showing a processing operation of a light irradiation device according to a first modified example of the first embodiment. FIG. 4 is a block diagram showing a schematic configuration of a light irradiation device according to a second embodiment. FIG. 5 is a block diagram showing a schematic configuration of a light irradiation device according to a third embodiment. FIG. 6 is a block diagram showing a schematic configuration of a light irradiation device according to a fourth embodiment. FIG. 7 is a flowchart showing a processing operation of a light irradiation device according to the fourth embodiment. FIG. 8 is a block diagram showing a schematic configuration of a light irradiation device according to a fifth embodiment. FIG. 9 is a block diagram showing a schematic configuration of a light irradiation system according to the present disclosure. FIG. 10 is an external view showing a binocular-type housing. FIG. 11 is an external view showing a housing of an HMD according to a first example. FIG. 12 is an external view showing a housing of an HMD according to a second example.

[0032] Hereinafter, embodiments of a light irradiation device and a light irradiation system will be described with reference to the drawings. The following description will focus on the main components of the light irradiation device and the light irradiation system, but the light irradiation device and the light irradiation system may include components and functions that are not shown or described. The following description does not exclude components and functions that are not shown or described.

[0033] (First embodiment) Fig. 1 is a block diagram showing a schematic configuration of a light irradiation device 1 according to the first embodiment. The light irradiation device 1 according to the first embodiment is a device designed to suppress the progression of myopia, for example. The light irradiation device 1 according to the first embodiment may be a stationary device or a portable device. If configured as a portable device, it may be a binocular type, an HMD (Head Mount Display) type, or any other eyewear device.

[0034] As shown in FIG. 1, the light irradiation device 1 according to the first embodiment includes a first measurement unit 2, a control unit 3, and a light source 4.

[0035] The first measurement unit 2 measures the pupil diameter of the subject. The first measurement unit 2 has, for example, a pupil diameter sensor. The pupil diameter sensor may be a CIS (CMOS Image Sensor) that photoelectrically converts visible light, or a sensor that photoelectrically converts light in the red to near-infrared wavelength range. Hereinafter, a sensor that photoelectrically converts visible light will be referred to as a visible light sensor, and a sensor that photoelectrically converts light in the red to near-infrared wavelength range will be referred to as a near-infrared light sensor. The first measurement unit 2 may have a visible light sensor or an infrared light sensor.

[0036] The control unit 3 controls the light irradiation amount of light irradiated onto the subject's eye 10 based on the pupil diameter measured by the first measurement unit 2. When the light irradiation amount per unit area irradiated by the light source 4 is constant, the larger the subject's pupil diameter, the greater the light irradiation amount. Therefore, since more light is irradiated onto subjects with larger pupil diameters, it is desirable for the control unit 3 to prohibit light irradiation for subjects whose pupil diameter exceeds a predetermined size (e.g., 4 mm). This can prevent the eye 10 of a subject with a large pupil diameter from being damaged by light irradiation.

[0037] The light source 4 may be any type, such as an LED (Light Emitting Device), laser, fluorescent lamp, or incandescent lamp. The wavelength of the light emitted from the light source 4 is, for example, light in the red to near-infrared wavelength range. Light in the red to near-infrared wavelength range is said to be effective in suppressing the progression of myopia, but some people believe that light in other wavelength ranges also has the effect of suppressing the progression of myopia. Therefore, the light source 4 may emit light in a wavelength range other than red to near-infrared (for example, ultraviolet, purple, or blue).

[0038] In this way, the light irradiation device 1 of Figure 1 controls the amount of light irradiated onto the subject's eye 10 based on the subject's pupil diameter, making it possible to prohibit light irradiation or reduce the amount of light irradiation for subjects with large pupil diameters.

[0039] Fig. 2 is a block diagram showing a schematic configuration of a light irradiation device 1a according to a first modified example of the first embodiment. The light irradiation device 1a according to the first modified example includes a second measurement unit 5, a first determination unit 6, and a warning unit 7 in addition to the configuration shown in Fig. 1.

[0040] The second measurement unit 5 measures the condition of the subject's eye 10. More specifically, the second measurement unit 5 measures the condition of the subject's retina, such as the ellipsoid zone. The second measurement unit 5 has, for example, a retinal sensor. Since retinal sensors are built into various devices, the second measurement unit 5 may be an optical length measurement device capable of measuring the thickness of the retina, such as a fundus camera, PCI (Partial Coherence Interferometry), OLCR (Optical Low Coherence Reflectometer), OLCI (Optical Low-Coherence Interferometry), or OCT (Optical Coherence Tomography).

[0041] The first determination unit 6 determines whether or not to irradiate the eye 10 of the subject with light, based on the state of the eye 10 of the subject measured by the second measurement unit 5 .

[0042] The control unit 3 determines whether or not to irradiate the eye 10 of the subject with light, based on the tomographic image of the retina generated based on the determination result of the first determination unit 6 .

[0043] When the first determination unit 6 determines that light should not be emitted, the warning unit 7 issues a warning that there is an abnormality in the subject's eye 10 and prohibits light emission from the light source 4. The warning unit 7 can warn the subject by, for example, sound or display. The displayed warning may be in the form of text or an image, or may be flashing, or may change color, etc.

[0044] 3 is a flowchart showing the processing operation of the light irradiation device 1a according to the first modification of the first embodiment. First, the second measurement unit 5 measures the condition of the eye 10 of the subject (step S1). More specifically, the second measurement unit 5 measures the condition of the cornea and retina of the subject.

[0045] Next, the first determination unit 6 determines whether or not to irradiate the eye 10 of the subject based on the measurement result of the second measurement unit 5 (step S2). If the first determination unit 6 determines not to irradiate the eye 10 based on the state of the cornea and retina of the subject, it issues a warning that there is an abnormality in the eye and prohibits the light source 4 from irradiating the eye (step S3).

[0046] If the first determination unit 6 determines in step S2 that light should be irradiated, the control unit 3 sets light irradiation conditions including the light irradiation amount (step S4) based on the pupil diameter measured by the first measurement unit 2. The light irradiation conditions include various conditions related to light irradiation, such as the light irradiation amount, light irradiation time, and light irradiation frequency.

[0047] Whether or not the subject's eye 10 is in an appropriate position can be determined by the measurement of the first measurement unit 2. For example, if the subject's eye 10 is in a position where it is not illuminated by light from the light source 4, this can be easily detected by the measurement of the first measurement unit 2. Therefore, if the subject's eye 10 is not in an appropriate position, the subject may be notified of this.

[0048] Next, the light source 4 starts emitting light based on the light irradiation conditions set by the control unit 3 (step S5). Next, when a predetermined irradiation time has elapsed, the light source 4 stops emitting light and saves the light irradiation conditions and the like as a log (step S6).

[0049] In this way, in the first embodiment, the amount of light irradiated onto the subject's eye 10 is controlled based on the results of measuring the subject's pupil diameter, so that the optimal amount of light can be irradiated onto the subject's eye 10, which can suppress the progression of myopia and eliminate the risk of damaging the human eye due to light irradiation.

[0050] Second Embodiment Fig. 4 is a block diagram showing a schematic configuration of a light irradiation device 1b according to a second embodiment. As shown in Fig. 4, the light irradiation device 1b according to the second embodiment includes a third measurement unit 11 and a confirmation unit 12 in addition to the configuration of the light irradiation device 1a in Fig. 2.

[0051] The third measurement unit 11 measures the axial length of the subject's eye 10. The third measurement unit 11 includes, for example, an axial length sensor. The axial length sensor optically measures the axial length from the cornea to the retina. More specifically, the axial length sensor measures the axial length from the difference between the receiving axis of light reflected by the cornea and the receiving axis of light reflected by the retina. The third measurement unit 11 may estimate the axial length using a retinal sensor instead of the axial length sensor. The third measurement unit 11 may measure the subject's axial length and the condition of the subject's eye. Alternatively, the third measurement unit 11 may measure the subject's axial length separately from the sensor that measures the condition of the subject's eye.

[0052] The confirmation unit 12 confirms the progression or suppression of myopia of the subject based on the axial length measured by the third measurement unit 11. As the myopia progresses, the axial length becomes longer, so the confirmation unit 12 can easily confirm the progression or suppression of myopia based on the axial length measured by the third measurement unit 11.

[0053] The control unit 3 controls the amount of light irradiation based on the progression or suppression of myopia confirmed by the confirmation unit 12. For example, when the control unit 3 determines that the progression of myopia is being suppressed, it stops the irradiation of light from the light source 4 or reduces the amount of light irradiation.

[0054] In this way, in the second embodiment, since the axial length is measured, it is possible to irradiate the subject with light while monitoring the progression and suppression of myopia. According to the second embodiment, it is possible to prevent the subject from being irradiated with light more than necessary, thereby improving the safety of the subject's eye 10.

[0055] With existing devices, in order to check the progression of myopia after light irradiation has begun, the subject needs to be diagnosed by a doctor, and there is a risk that more light than necessary will be irradiated onto the subject's eye until the doctor's diagnosis is received.In contrast, in the third embodiment, the progression and suppression of myopia can be checked while light irradiation is being performed, thereby preventing the risk of irradiating more light than necessary onto the subject's eye 10.

[0056] Third Embodiment Fig. 5 is a block diagram showing a schematic configuration of a light irradiation device 1c according to a third embodiment. As shown in Fig. 5, the light irradiation device 1c according to the third embodiment includes a fourth measurement unit 13 and an authentication unit 14 in addition to the configuration of the light irradiation device 1a in Fig. 2.

[0057] The fourth measurement unit 13 measures the pattern of the iris of the subject. The fourth measurement unit 13 includes, for example, an iris sensor. The iris sensor captures an image of the iris of a human eye and identifies the iris pattern. The iris sensor can be replaced with a visible light sensor or a near-infrared light sensor. The fourth measurement unit 13 may also use a pupil diameter sensor that measures the pupil diameter. In this case, the fourth measurement unit 13 can measure the pattern of the subject's eye 10 and the pupil diameter of the subject. Alternatively, the fourth measurement unit 13 may include a sensor (third sensor) that measures the pattern of the subject's iris, separate from the sensor that measures the pupil diameter of the subject.

[0058] The authentication unit 14 authenticates the subject based on the pattern of the subject's iris measured by the fourth measurement unit 13. In existing devices, the subject is required to input an ID, password, etc. when irradiating the subject with light, but in the fourth embodiment, the subject can be authenticated by the fourth measurement unit 13 and the authentication unit 14 by simply looking into the eyepiece. This eliminates the need for the subject to input an ID and password, saving the subject time and effort and preventing impersonation.

[0059] In this way, in the third embodiment, the authentication unit 14 authenticates the subject based on the iris pattern of the subject measured by the fourth measurement unit 13, so that light can be irradiated only to legitimate subjects without the subject having to enter an ID and password themselves, eliminating the risk of irradiating light onto the eyes of unintended people.

[0060] It is also possible to realize a configuration in which the third measurement unit 11 and confirmation unit 12 in the second embodiment and the fourth measurement unit 13 and authentication unit 14 in the third embodiment are added to the light irradiation device 1a in Figure 2.

[0061] 6 is a block diagram showing a schematic configuration of a light irradiation device 1d according to a fourth embodiment. As shown in Fig. 6, the light irradiation device 1d according to the fourth embodiment includes a fifth measurement unit 15 and a second determination unit 16 in addition to the configuration of the light irradiation device 1a in Fig. 2.

[0062] The fifth measurement unit 15 measures the subject's gaze. The fifth measurement unit 15 has, for example, a gaze detection sensor (eye tracking sensor). The gaze detection sensor detects the visual field and gaze movement from the positional relationship between the light reflected by the cornea and the pupil. The fifth measurement unit 15 may detect the gaze using a pupil diameter sensor instead of the gaze detection sensor. In this case, the fifth measurement unit 15 measures the subject's gaze and at least one of the subject's pupil diameter or iris pattern.

[0063] The second determination unit 16 determines whether or not the light from the light source 4 is irradiated onto the eye 10 of the subject, based on the line of sight measured by the fifth measurement unit 15 .

[0064] In addition, the light irradiation device 1d according to the fourth embodiment may include at least one of the third measurement unit 11 and confirmation unit 12 provided in the light irradiation device 1b according to the second embodiment, and the fourth measurement unit 13 and authentication unit 14 provided in the light irradiation device 1c according to the third embodiment.

[0065] 7 is a flowchart showing the processing operation of the light irradiation device 1d according to the fourth embodiment. Steps S11 to S15 are the same as steps S1 to S5 in FIG.

[0066] While the light from the light source 4 is being irradiated onto the eye 10 of the subject, the fifth measurement unit 15 measures the position of the eye 10 of the subject and the opening and closing of the eyelid (step S16).

[0067] Based on the measurement result of the fifth measurement unit 15, it is determined whether the position of the subject's eye 10 is displaced from the light irradiation position (step S17).

[0068] If it is determined in step S17 that the position of the subject's eye 10 is misaligned, and if the direction of light emitted from the light source 4 can be adjusted, the direction of light emission is adjusted based on the measurement results of the fifth measurement unit 15 (step S18). Adjustment of the direction of light emission from the light source 4 can be performed, for example, using an optical scanning device. In step S18, the direction of light emission is adjusted so that the light from the light source 4 illuminates the subject's eye 10. If adjustment of the direction of light emission from the light source 4 is not possible, a warning is given to the subject by a display or sound that the position of the subject's eye 10 is misaligned (step S19). Upon receiving this warning, the subject changes the position of their eye or the direction of their gaze. In this specification, the processes of steps S18 and S19 are collectively referred to as the processing of the adjustment unit.

[0069] If it is determined in step S17 that the position of the subject's eye 10 is not shifted, and if the processing of step S18 or S19 is performed, the time that light is irradiated onto the subject's eye 10 is measured based on the measurement results of the fifth measurement unit 15 (step S20).

[0070] If the time during which light is irradiated onto the subject's eye 10 exceeds a predetermined time, the light irradiation from the light source 4 is stopped, and log information of the light irradiation conditions is saved (step S21).

[0071] As described above, in the fourth embodiment, while light is being irradiated onto the subject's eye 10, the position of the subject's eye 10 is measured by the fifth measurement unit 15, and light is irradiated onto the subject's eye 10 based on the measured line of sight of the subject. Furthermore, based on the measurement result of the fifth measurement unit 15, the time for which light is irradiated onto the subject's eye 10 is measured, and light is not irradiated onto the subject's eye 10 for longer than a predetermined time. This prevents light from being irradiated onto the subject's eye 10 for longer than necessary, and allows light from the light source 4 to be efficiently irradiated onto the subject's eye 10.

[0072] Fifth Embodiment Fig. 8 is a block diagram showing a schematic configuration of a light irradiation device 1e according to a fifth embodiment. As shown in Fig. 8, the light irradiation device 1e according to the fifth embodiment includes a communication unit 17 in addition to the configuration shown in Fig. 2. The communication unit 17 transmits measurement data of the subject including the pupil diameter measured by the first measurement unit 2. The communication destination of the communication unit 17 is not limited, and may be, for example, a server on a cloud or a storage device 18.

[0073] The light irradiation device 1e according to the fifth embodiment may include at least one of the third measurement unit 11 and the confirmation unit 12 included in the light irradiation device 1b according to the second embodiment, the fourth measurement unit 13 and the authentication unit 14 included in the light irradiation device 1c according to the third embodiment, and the fifth measurement unit 15 included in the light irradiation device 1d according to the fourth embodiment. Below, an example will be described in which the communication unit 17 transmits measurement data to the storage device 18 on the cloud.

[0074] The doctor or administrator accesses the storage device 18 on the cloud and reads out the measurement data. The measurement data stored in the storage device 18 by the communication unit 17 includes the subject's pupil diameter, retinal thickness, corneal thickness, the number of times light is irradiated from the light source 4, the irradiation time, and axial length. The measurement data may also include information on responses to a questionnaire given by the subject after using the light irradiation device 1.

[0075] The doctor or administrator changes the light irradiation conditions or determines whether to continue or stop the light irradiation based on the measurement data read from the cloud-based storage device 18. For example, if the subject's questionnaire response information includes a response that the light from the light source 4 is too bright, the doctor or administrator changes the light irradiation conditions, such as reducing the amount of light irradiation or the frequency of light irradiation.

[0076] In this way, in the fifth embodiment, measurement data from the first measurement unit 2, etc. is transmitted to a predetermined communication destination (for example, a storage device 18 on the cloud) via the communication unit 17, so that a doctor or administrator in a remote location can read the measurement data from the storage device 18 and adjust the light irradiation conditions as needed.

[0077] Although the light irradiation devices 1 to 1e according to the first to fifth embodiments have been described above mainly as examples of irradiating light for the purpose of suppressing the progression of myopia, it is said that irradiating light onto the subject's eye 10 is also effective for treating amblyopia, glaucoma, age-related macular degeneration (AMD), diabetic retinopathy, etc. Therefore, the light irradiation devices 1 to 1e according to the first to fifth embodiments can also be applied when irradiating light for the purpose of treating various diseases.

[0078] (Light Irradiation System) The light irradiation devices 1 to 1e according to the first to fifth embodiments can be incorporated into a light irradiation system.

[0079] Fig. 9 is a block diagram showing a schematic configuration of a light irradiation system according to the present disclosure. As shown in Fig. 9, a light irradiation system 20 according to the present disclosure includes the light irradiation devices 1 to 1e according to the first to fifth embodiments and a management device 21. Below, an example will be described in which the light irradiation system 20 includes the light irradiation device 1a shown in Fig. 2.

[0080] The management device 21 manages the light irradiation conditions under which the light irradiation device 1 a irradiates light. More specifically, the management device 21 manages the light irradiation conditions that are set based on the eye condition of the subject measured by the second measurement unit.

[0081] The light irradiation conditions managed by the management device 21 include at least one of whether or not to irradiate the subject's eyes with light, the frequency at which light is irradiated to the subject's eyes, and the amount of light irradiated to the subject's eyes.

[0082] (Portable Light Irradiation Device) The light irradiation devices 1 to 1e according to the first to fifth embodiments can be housed in, for example, a portable housing. Representative external views of the portable light irradiation devices 1 to 1e are shown below.

[0083] Figure 10 is an external view of a binocular-type housing 22. The binoculars of Figure 10 are equipped with eyepieces 23, through which the subject looks with both eyes, allowing light from a light source to be irradiated onto the subject's eyes. The binoculars of Figure 10 can be carried by the subject using a strap. This allows the subject to easily irradiate the light onto their eyes even when they are not at home, eliminating the drawbacks of stationary devices, such as the limitations on the number of times light can be irradiated and the location of the light irradiation.

[0084] FIG. 11 is an external view showing the housing of an HMD 110 according to a first example. When a subject wears the HMD 110 of FIG. 11, light from a light source can be irradiated onto the subject's eyes. The HMD 110 of FIG. 11 has, for example, ear hooks 112 on both sides of a glasses-shaped display unit 111 for wearing on the user's head. By incorporating the functions of the light irradiation devices 1 to 1e according to the first to fifth embodiments into such an HMD 110, the subject can irradiate light onto their eyes regardless of location or time.

[0085] FIG. 12 is an external view showing the housing of an HMD 120 according to a second example. The HMD 120 in FIG. 12 is a see-through HMD having a main body 121, an arm 122, and a lens barrel 123. The HMD 120 is attached to eyeglasses 128. The main body 121 has a control board and a display unit for controlling the operation of the HMD 120. The display unit emits image light of a display image. The arm 122 connects the main body 121 to the lens barrel 123 and supports the lens barrel 123. The lens barrel 123 projects the image light supplied from the main body 121 via the arm 122 toward the user's eyes via lenses 129 of the eyeglasses 128. The techniques according to the above-described embodiments can be applied to such an HMD 120.

[0086] The HMD 120 is a so-called light guide plate type HMD, but is not limited to this and may be, for example, a so-called birdbath type HMD. The birdbath type HMD includes, for example, a beam splitter and a partially transparent mirror. The beam splitter outputs light encoded with image information toward the mirror, and the mirror reflects the light toward the user's eyes. Both the beam splitter and the partially transparent mirror are partially transparent. This allows light from the surrounding environment to reach the user's eyes.

[0087] The present technology may be configured as follows: (1) A light irradiation device comprising: a first measurement unit that measures a pupil diameter of a subject; a control unit that controls an irradiation amount of light to be irradiated to the eye of the subject based on the pupil diameter measured by the first measurement unit; and a light source that irradiates light at an irradiation amount controlled by the control unit. (2) The light irradiation device described in (1), comprising: a second measurement unit that measures a state of the eye of the subject; and a first determination unit that determines whether or not to irradiate the eye of the subject with light based on the state of the eye of the subject measured by the second measurement unit, wherein the control unit decides whether or not to irradiate the eye of the subject with light based on the determination result of the first determination unit. (3) The light irradiation device described in (2), wherein the second measurement unit irradiates a retina of the subject with light and receives reflected light from the retina, and the first determination unit determines whether or not to irradiate the eye of the subject with light based on a tomographic image of the retina generated based on the measurement result of the second measurement unit. (4) The light irradiation device according to any one of (1) to (3), comprising: a third measurement unit that measures the axial length of the eye of the subject; and a confirmation unit that confirms the progression or suppression of myopia of the subject based on the axial length measured by the third measurement unit. (5) The light irradiation device according to (4), wherein the third measurement unit irradiates the cornea of ​​the subject with light and receives reflected light from the cornea, and measures the axial length based on the result of irradiating the retina of the subject with light and receiving reflected light from the retina. (6) The light irradiation device according to (4) or (5), wherein the third measurement unit measures the axial length of the subject and includes a first sensor that measures the condition of the eye of the subject. (7) The light irradiation device according to (4) or (5), wherein the third measurement unit includes a first sensor that measures the axial length of the subject, separate from a sensor that measures the condition of the eye of the subject. (8) The light irradiation device according to any one of (1) to (7), further comprising: a fourth measurement unit that measures an iris pattern of the subject; and an authentication unit that authenticates the subject based on the iris pattern measured by the fourth measurement unit.(9) The light irradiation device according to any one of (1) to (8), comprising: a fifth measurement unit that measures the gaze of the subject; and a second determination unit that determines whether light is irradiated to the eye of the subject based on the gaze measured by the fifth measurement unit. (10) The light irradiation device according to (9), comprising: an adjustment unit that adjusts the irradiation direction of light from the light source or prompts the subject to adjust the position of their eye when the second determination unit determines that light is not irradiated to the eye of the subject. (11) The light irradiation device according to (9), wherein the fifth measurement unit measures the gaze of the subject and has a sensor that measures at least one of the pupil diameter or iris pattern of the subject. (12) The light irradiation device according to (9), wherein the fifth measurement unit has a second sensor that detects the gaze of the subject, separate from the sensor that measures at least one of the pupil diameter or iris pattern of the subject. (13) The light irradiation device according to (8), wherein the fourth measurement unit measures the pattern of the iris of the subject and also measures the pupil diameter of the subject, or includes a third sensor that measures the pattern of the iris of the subject separately from the sensor that measures the pupil diameter of the subject. (14) The light irradiation device according to any one of (1) to (13), comprising a communication unit that transmits measurement data of the subject including the pupil diameter measured by the first measurement unit. (15) The light irradiation device according to any one of (1) to (14), comprising a stationary or portable housing that incorporates the first measurement unit and the control unit. (16) The light irradiation device according to (15), wherein the housing is a housing of binoculars, an HMD device, or an eyewear device. (17) The light irradiation device according to any one of (1) to (16), wherein the light irradiated to the eyes of the subject is light in a wavelength range from red light to near-infrared light.(18) A light irradiation system comprising: a light irradiation device that irradiates a subject's eye with light of a predetermined wavelength; and a management device that manages light irradiation conditions for the light irradiation device, wherein the light irradiation device has: a first measurement unit that measures the subject's pupil diameter; a second measurement unit that measures the subject's eye condition; and a control unit that controls an amount of light irradiation to the subject's eye based on the pupil diameter measured by the first measurement unit, and the management device manages the light irradiation conditions that are set based on the subject's eye condition measured by the second measurement unit. (19) The light irradiation system according to claim 18, wherein the light irradiation conditions managed by the management device include at least one of whether or not to irradiate the subject's eye with light, a frequency of irradiating the subject's eye with light, and an amount of light irradiation to the subject's eye.

[0088] The aspects of the present disclosure are not limited to the individual embodiments described above, but include various modifications that may be conceived by those skilled in the art, and the effects of the present disclosure are not limited to the above-described contents. In other words, various additions, modifications, and partial deletions are possible within the scope of the conceptual idea and spirit of the present disclosure, which is derived from the contents defined in the claims and their equivalents.

[0089] 1, 1a, 1b, 1c, 1d, 1e Light irradiation device, 2 First measurement unit, 3 Control unit, 4 Light source, 5 Second measurement unit, 6 First judgment unit, 7 Warning unit, 10 Eye, 11 Third measurement unit, 12 Confirmation unit, 13 Fourth measurement unit, 14 Authentication unit, 15 Fifth measurement unit, 16 Second judgment unit, 17 Communication unit, 18 Storage device, 20 Light irradiation system, 21 Management device, 22 Housing, 23 Eyepiece, 111 Display unit, 112 Ear hook unit, 120 HMD, 121 Main body unit, 122 Arm unit, 123 Lens barrel unit, 128 Glasses, 129 Lens

Claims

1. A light irradiation device comprising: a first measurement unit that measures the pupil diameter of a subject; a control unit that controls the amount of light irradiation to be irradiated onto the eye of the subject based on the pupil diameter measured by the first measurement unit; and a light source that irradiates light with the amount of light irradiation controlled by the control unit.

2. A light irradiation device as described in claim 1, comprising: a second measurement unit that measures the condition of the subject's eye; and a first judgment unit that judges whether or not to irradiate light to the subject's eye based on the condition of the subject's eye measured by the second measurement unit, wherein the control unit decides whether or not to irradiate light to the subject's eye based on the judgment result of the first judgment unit.

3. The light irradiation device according to claim 2, wherein the second measurement unit irradiates light onto the subject's retina and receives light reflected from the retina, and the first determination unit determines whether or not to irradiate light onto the subject's eye based on a tomographic image of the retina generated based on the measurement results of the second measurement unit.

4. The light irradiation device according to claim 1, further comprising: a third measurement unit that measures the axial length of the subject's eye; and a confirmation unit that confirms the progression or suppression status of the subject's myopia based on the axial length measured by the third measurement unit.

5. The light irradiation device according to claim 4, wherein the third measurement unit irradiates the cornea of ​​the subject with light and receives the light reflected from the cornea, and measures the axial length based on the results of irradiating the retina of the subject with light and receiving the light reflected from the retina.

6. The light irradiation device according to claim 4, wherein the third measurement unit measures the axial length of the subject's eye and has a first sensor that measures the condition of the subject's eye.

7. The light irradiation device according to claim 4, wherein the third measurement unit has a first sensor that measures the axial length of the subject's eye, separate from a sensor that measures the condition of the subject's eye.

8. The light irradiation device according to claim 1, comprising: a fourth measurement unit that measures the iris pattern of the subject; and an authentication unit that authenticates the subject based on the iris pattern measured by the fourth measurement unit.

9. The light irradiation device according to claim 1, comprising: a fifth measurement unit that measures the line of sight of the subject; and a second determination unit that determines whether or not light is irradiated onto the eye of the subject based on the line of sight measured by the fifth measurement unit.

10. A light irradiation device as described in claim 9, further comprising an adjustment unit that adjusts the direction of light irradiation from the light source or prompts the subject to adjust the position of their eyes when the second judgment unit determines that light is not being irradiated onto the subject's eyes.

11. The light irradiation device according to claim 9, wherein the fifth measurement unit has a sensor that measures the subject's line of sight and measures at least one of the subject's pupil diameter or iris pattern.

12. The light irradiation device according to claim 9, wherein the fifth measurement unit has a second sensor that detects the line of sight of the subject, separate from a sensor that measures at least one of the pupil diameter or iris pattern of the subject.

13. The light irradiation device according to claim 8, wherein the fourth measurement unit measures the iris pattern of the subject and also measures the pupil diameter of the subject, or has a third sensor that measures the iris pattern of the subject separately from the sensor that measures the pupil diameter of the subject.

14. The light irradiation device according to claim 1, further comprising a communication unit that transmits measurement data of the subject, including the pupil diameter measured by the first measurement unit.

15. The light irradiation device according to claim 1, comprising a stationary or portable housing that houses the first measurement unit and the control unit.

16. The light irradiation device according to claim 15, wherein the housing is a housing for binoculars, an HMD device, or an eyewear device.

17. The light irradiation device according to claim 1, wherein the light irradiated onto the subject's eye is light in the wavelength range from red light to near-infrared light.

18. A light irradiation system comprising: a light irradiation device that irradiates light of a predetermined wavelength onto the eye of a subject; and a management device that manages the light irradiation conditions under which the light irradiation device irradiates, wherein the light irradiation device has a first measurement unit that measures the pupil diameter of the subject; a second measurement unit that measures the condition of the eye of the subject; and a control unit that controls the amount of light irradiation to be irradiated onto the eye of the subject based on the pupil diameter measured by the first measurement unit; and the management device manages the light irradiation conditions that are set based on the condition of the eye of the subject measured by the second measurement unit.

19. The light irradiation system according to claim 18, wherein the light irradiation conditions managed by the management device include at least one of whether or not to irradiate the subject's eye with light, the frequency at which light is irradiated to the subject's eye, and the amount of light irradiated to the subject's eye.

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