An LED narrow-spectrum red light ocular irradiation optical system for improving choroidal blood circulation

Abstract

This invention discloses an LED narrowband red light ocular irradiation optical system for improving choroidal blood circulation. The system includes an LED red light source, a first lens, a second lens, a narrowband red light filter, and a light-shielding lens tube, with an ocular surface positioning structure at the light-emitting end. The broadband divergent red light generated by the LED red light source is collected and initially collimated by the first lens, then further collimated and shaped by the second lens to control the incident angle of the beam entering the filter. The beam then passes through the narrowband red light filter to filter the target wavelength band, ultimately forming a low-intensity narrowband red light irradiation spot at the target ocular surface location with a center wavelength of 645-655 nm, a half-width at half-maximum (HW) of 5 nm ± 1 nm, a spot diameter of 9 mm ± 1 mm, and an ocular surface power of 1.5 ± 0.3 mW or 2.0 ± 0.3 mW. This invention solves the problems of wide red light spectrum, large divergence angle, spectral drift and full width at half maximum (FWHM) broadening caused by the incident angle of the filter, and achieves narrow-spectrum red light output from non-laser LED light sources through the synergistic cooperation of dual-lens collimation and narrow-band filter.

Description

Technical Field

[0001] This invention relates to the field of narrow-spectrum optical irradiation systems, and more particularly to an LED narrow-spectrum red light eye irradiation optical system for improving choroidal blood circulation. Background Technology

[0002] Currently, some devices used for myopia prevention or red light therapy in children and adolescents employ lasers or semiconductor lasers as the red light source. Laser sources have advantages such as concentrated wavelength, narrow spectral half-width, and relatively easy power control. However, their strong coherence makes them prone to speckle effects, which may cause uneven local energy distribution. In home or long-term use scenarios, higher requirements are placed on safety control, power stability, eye positioning, and user compliance.

[0003] Compared to laser light sources, LED light sources have advantages such as low coherence, weak speckle effect, lower cost, stable structure, mature supply chain, and higher safety acceptance. However, ordinary LED red light has problems such as a wide original spectrum, large divergence angle, low energy utilization, difficulty in controlling the spot size, and difficulty in compressing the final ocular surface output half-width at half-maximum, making it difficult to directly meet the requirements of low-intensity narrow-spectrum red light irradiation of the eye.

[0004] Narrowband red light filters can filter target wavelengths, but their spectral transmission characteristics are closely related to the incident angle. When the incident beam has a large angular distribution, the center wavelength of the filter may drift, and the final output half-width at half-maximum (HWHM) may broaden. Therefore, it is difficult to stably obtain a narrowband red light output with a HWHM of approximately 5 nm using only an LED light source and a filter.

[0005] Existing publicly available technologies include LED light source devices, light source generation methods, and light-enhancing devices, such as CN202511728182.9, "An LED light source device, light source generation method, and light-enhancing device." These solutions demonstrate the potential application of LED light sources in eye illumination or myopia control equipment, but further solutions are needed to address issues such as narrowing the LED broadband spectrum, controlling the incident angle of the filter, ensuring stable formation of light spots on the ocular surface, controlling low-intensity power, and matching application parameters to improve choroidal blood flow.

[0006] The existing technology has at least the following shortcomings:

[0007] Laser light sources have strong coherence, resulting in speckle effect and uneven local energy distribution, which is not conducive to uniform energy control in low-intensity eye irradiation scenarios.

[0008] Ordinary LED light sources have a wide original spectrum, making it difficult to directly obtain red light output with a narrow half-width at half-maximum.

[0009] LEDs have a large divergence angle. If they are not effectively collected, collimated, and shaped, the size of the light spot on the eye surface can easily become unstable, making it difficult to control the irradiation area and power density.

[0010] Narrowband filters are sensitive to the angle of incidence. When the angle of incidence of the beam is too large, it can easily lead to center wavelength drift and full width at half maximum (FWHM) broadening.

[0011] Existing structures often focus only on the red light output itself, lacking coordinated design of the target distance on the ocular surface, spot diameter, ocular surface power, half width at half maximum (FWHM), center wavelength, and incident angle.

[0012] When existing low-intensity red light devices are used for eye irradiation, there is a lack of structured design schemes that match the optical parameters to achieve the application goal of improving choroidal blood circulation. Summary of the Invention

[0013] The purpose of this invention is to provide an LED narrow-spectrum red light eye irradiation optical system for improving choroidal blood circulation, which solves the above-mentioned technical problems pointed out in the prior art.

[0014] This invention provides an LED narrowband red light eye irradiation optical system for improving choroidal blood circulation, comprising: an LED red light source, a first lens, a second lens, a narrowband red light filter, and a light-shielding lens tube;

[0015] The LED red light source is located at the beginning of the optical path and is used to generate original broadband divergent red light;

[0016] The first lens is positioned after the LED red light source to collect and initially collimate the LED's diffused light.

[0017] The second lens is disposed after the first lens and is used to further collimate and shape the beam after it has been initially collimated by the first lens, so as to control the beam divergence angle and the incident angle of the beam entering the narrow band red light filter.

[0018] The narrowband red light filter is disposed after the second lens to filter the target red light band and cut off non-target bands so as to output narrowband red light.

[0019] The light-shielding lens tube is used to cover and fix the LED red light source, the first lens, the second lens, and the narrow-band red light filter to reduce stray light and maintain the relative position stability of each optical element along the optical axis. The system also includes an ocular surface positioning structure set at the light-emitting end to keep the target ocular surface within a preset working distance range so as to form a narrow-band red light irradiation spot with a stable diameter at the target ocular surface position.

[0020] Preferably, as one possible implementation, the first lens and the second lens constitute a dual-lens collimation and shaping structure, used to control the incident angle of the light beam entering the narrowband red light filter between 0° and 10°; and both the first lens and the second lens are convex lenses. That is, after being collimated and shaped by the first lens and the second lens, the incident angle of the light beam entering the narrowband red light filter is controlled within the range of 0-10°.

[0021] Preferably, as one possible implementation, the incident angle of the light beam is controlled between 0° and 5°.

[0022] Preferably, as one possible implementation, the LED red light source is a non-laser light source to reduce coherence and speckle effect.

[0023] Preferably, as one possible implementation, the narrowband red light output by the narrowband red light filter has a center wavelength of 645-655 nm and an output half-width at half-maximum of 5 nm ± 1 nm.

[0024] Preferably, as one possible implementation, the diameter of the red light irradiation spot formed at the target ocular surface location is 6-12 mm.

[0025] Preferably, as one possible implementation, the diameter of the red light irradiation spot formed at the target ocular surface location is 9 mm ± 1 mm.

[0026] Preferably, as one possible implementation, the LED narrow-spectrum red light eye illumination optical system further includes a power control module electrically connected to the LED red light source, used to control the output power of the LED red light source so that the output power of the eye surface at the target eye surface position is 0.5-3.0 mW.

[0027] In the optimal technical solution, the power control module makes the ocular surface output power at the target ocular surface location 1.5±0.3 mW or 2.0±0.3 mW.

[0028] Preferably, as one possible implementation: the target working distance is 50-120 mm; the distance from the LED red light source to the first lens is 0.5-5 mm; the distance from the first lens to the second lens is 10-40 mm; and the distance from the second lens to the narrowband red light filter is 0-10 mm.

[0029] Preferably, as one possible implementation, the cutoff depth of the narrowband red light filter is not less than OD3, and the peak transmittance is not less than 60%.

[0030] Preferably, as one possible implementation, the LED narrow-spectrum red light eye illumination optical system further includes one or more of the following modules: a light power detection module for real-time detection of the output power of the LED red light source; an eye position detection module, located near the eye positioning area, for determining whether the eye is located at a preset illumination position; a usage time control module for controlling the duration of a single illumination session; a left and right eye independent control module for independently controlling the optical paths of the left and right eyes respectively; and a main control module electrically connected to the power control module, light power detection module, eye position detection module, usage time control module, and left and right eye independent control module respectively, for coordinating and controlling the working status of each module.

[0031] This invention provides an application of the LED narrow-spectrum red light eye irradiation optical system in the preparation of an eye irradiation device for improving choroidal blood circulation. The low-intensity narrow-spectrum red light output by the system enters the fundus region through the eye's refractive medium, irradiating the retina and choroid region at a low intensity to help improve choroidal blood circulation and fundus microcirculation.

[0032] Compared with the prior art, the embodiments of the present invention have at least the following technical advantages:

[0033] Analysis of the LED narrow-band red light ocular irradiation optical system for improving choroidal blood circulation provided by the present invention reveals that the system sequentially includes an LED red light source, a first lens, a second lens, a narrow-band red light filter, and a light-shielding lens along the optical axis, with an ocular surface positioning structure at the light-emitting end. The broadband divergent red light generated by the LED red light source is collected and initially collimated by the first lens, then further collimated and shaped by the second lens to control the incident angle of the beam entering the filter. The target wavelength is then filtered by the narrow-band red light filter, ultimately forming a low-intensity narrow-band red light irradiation spot at the target ocular surface location with a center wavelength of 645-655 nm, a half-width at half-maximum of 5 nm ± 1 nm, a spot diameter of 9 mm ± 1 mm, and an ocular surface power of 1.5 ± 0.3 mW or 2.0 ± 0.3 mW. This invention solves the problems of wide red light spectrum, large divergence angle, spectral drift and full width at half maximum (FWHM) broadening caused by the incident angle of the filter, and achieves narrow-spectrum red light output from non-laser LED light sources through the synergistic cooperation of dual-lens collimation and narrow-band filter. It can help improve choroidal blood circulation and fundus microcirculation and is suitable for core optical modules in myopia control equipment. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of the principle structure of an LED narrow-spectrum red light eye irradiation optical system for improving choroidal blood circulation.

[0035] Figure 2This is a schematic diagram of the main structure of an LED narrow-spectrum red light eye irradiation optical system for improving choroidal blood circulation. Detailed Implementation

[0036] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0037] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be described in detail below with reference to the accompanying drawings and specific embodiments. Obviously, the described embodiments are merely some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0038] The present invention will now be described in further detail with reference to specific embodiments and accompanying drawings.

[0039] Example 1

[0040] See Figure 2 Embodiment 1 of the present invention provides an LED narrowband red light eye irradiation optical system for improving choroidal blood circulation, comprising: an LED red light source 10, a first lens 20, a second lens 30, a narrowband red light filter 40, and a light-shielding lens tube 50;

[0041] The LED red light source 10 is located at the beginning of the optical path and is used to generate original broadband divergent red light;

[0042] The first lens 20 is disposed after the LED red light source and is used to collect and initially collimate the divergent light emitted by the LED;

[0043] The second lens 30 is disposed after the first lens and is used to further collimate and shape the beam after it has been initially collimated by the first lens, so as to control the beam divergence angle and the incident angle of the beam entering the narrow band red light filter.

[0044] The narrowband red light filter 40 is disposed after the second lens and is used to filter the target red light band and cut off non-target bands to output narrowband red light.

[0045] The light-shielding lens tube 50 is used to cover and fix the LED red light source, the first lens, the second lens and the narrow-band red light filter to reduce stray light and maintain the relative position stability of each optical element along the optical axis. The system also includes an ocular surface positioning structure set at the light-emitting end to keep the target ocular surface within a preset working distance range so as to form a narrow-band red light irradiation spot with a stable diameter at the target ocular surface position.

[0046] The above-mentioned LED narrow-spectrum red light eye irradiation optical system for improving choroidal blood circulation can be seen in the following physical effect diagram. Figure 2 The optical system setup sequence is as follows: LED → convex lens 1 → convex lens 2 → red light filter → finally reaching the eye surface.

[0047] The total axial spacing is approximately 97.29 mm (the spacings in the table are added together, excluding the thickness of the components themselves).

[0048] Preferably, as one possible implementation, the first lens and the second lens constitute a dual-lens collimation and shaping structure, used to control the incident angle of the light beam entering the narrowband red light filter between 0° and 10°; and both the first lens and the second lens are convex lenses. That is, after being collimated and shaped by the first lens and the second lens, the incident angle of the light beam entering the narrowband red light filter is controlled within the range of 0-10°.

[0049] Preferably, as one possible implementation, the incident angle of the light beam is controlled between 0° and 5°.

[0050] Preferably, as one possible implementation, the LED red light source is a non-laser light source to reduce coherence and speckle effect.

[0051] Preferably, as one possible implementation, the narrowband red light output by the narrowband red light filter has a center wavelength of 645-655 nm and an output half-width at half-maximum of 5 nm ± 1 nm.

[0052] Preferably, as one possible implementation, the diameter of the red light irradiation spot formed at the target ocular surface location is 6-12 mm.

[0053] Preferably, as one possible implementation, the diameter of the red light irradiation spot formed at the target ocular surface location is 9 mm ± 1 mm.

[0054] Preferably, as one possible implementation, the LED narrow-spectrum red light eye illumination optical system further includes a power control module electrically connected to the LED red light source, used to control the output power of the LED red light source so that the output power of the eye surface at the target eye surface position is 0.5-3.0 mW.

[0055] In the optimal technical solution, the power control module makes the ocular surface output power at the target ocular surface location 1.5±0.3 mW or 2.0±0.3 mW.

[0056] Preferably, as one possible implementation: the target working distance is 50-120 mm; the distance from the LED red light source to the first lens is 0.5-5 mm; the distance from the first lens to the second lens is 10-40 mm; and the distance from the second lens to the narrowband red light filter is 0-10 mm.

[0057] Preferably, as one possible implementation, the narrowband red light filter has a cutoff depth of not less than OD3 and a peak transmittance of not less than 60%.

[0058] Preferably, as one possible implementation, the LED narrow-spectrum red light eye illumination optical system further includes one or more of the following modules: a light power detection module for real-time detection of the output power of the LED red light source; an eye position detection module, located near the eye positioning area, for determining whether the eye is located at a preset illumination position; a usage time control module for controlling the duration of a single illumination session; a left and right eye independent control module for independently controlling the optical paths of the left and right eyes respectively; and a main control module electrically connected to the power control module, light power detection module, eye position detection module, usage time control module, and left and right eye independent control module respectively, for coordinating and controlling the working status of each module.

[0059] The following is a detailed explanation of a specific case of an LED narrow-spectrum red light optical system used for low-intensity red light illumination of the eye:

[0060] Overall Structure

[0061] See Figure 2 This invention provides an LED narrowband red light optical system (i.e., a monocular optical system structure) for low-intensity red light illumination of the eye. The system uses an LED red light source as the primary light source, and a first lens, a second lens, and a narrowband red light filter are sequentially arranged along the optical axis.

[0062] The broadband divergent red light emitted by the LED red light source is first collected and collimated by a first lens, and then further collimated and shaped by a second lens, controlling the beam divergence angle and the incident angle entering the narrowband red light filter. The red light, collimated and shaped by the two lenses, enters the narrowband red light filter, which cuts off non-target wavelengths and filters the target red light wavelengths, ultimately forming a low-intensity narrowband red light spot on the target ocular surface.

[0063] This system, through the coordinated design of LED light source, dual-lens collimation and shaping structure, narrow-band red light filter, black light-shielding lens barrel, ocular surface positioning structure and power control module, enables the output red light to have a narrow half-width at half-maximum, stable center wavelength, stable ocular surface spot and controllable ocular surface power.

[0064] Regarding the above system composition and the relationship between its parts: This system mainly includes an LED red light source, a first lens, a second lens, a narrow-band red light filter, a black light-shielding lens tube or optical fixing cavity, an ocular surface positioning structure, an LED driver and power control module, a light power detection module, an eye position detection module, a usage time control module, a left and right eye independent control module, and a main control module.

[0065] Serial Number Component Name Positional Relationship Functions and uses 1 LED red light source Located at the starting end of the optical path It produces raw red light as a non-laser low-coherence light source. 2 First lens Located after the LED red light source The diffused light emitted by LEDs is initially collected and collimated to improve the light energy utilization rate. 3 Second lens Located after the first lens Further adjust the beam divergence angle, spot size, and incident angle into the filter. 4 Narrowband red light filter Located after the second lens Select the target red light band, cut off non-target bands, and compress the output half-width at half-maximum. 5 Black lens hood Encapsulate and fix the main optical components Fixing the position of optical components reduces stray light and improves optical path stability. 6 Ocular surface positioning structure Set at the light-emitting end or eye contact / positioning area Keep the eye surface and the light-emitting end within the preset working distance range. 7 Power control module Connect to LED driver circuit Control the LED output power to keep the power on the ocular surface within a low intensity range. 8 Eye position detection module Placed near the eye-tracking area Determine whether the eye is in the preset irradiation position to reduce the risk of accidental irradiation.

[0066] Optical parameters:

[0067] This system can generate low-intensity narrow-spectrum red light output to the target ocular surface using the following parameter range and preferred parameters. Specific parameters can be determined based on prototype test results, optical structure design, and product registration path.

[0068] Parameter categories Design Scope Preferred range Specific Implementation Light source type LED red light source Non-laser LED red light source led center wavelength 640-660 nm 645-655 nm Approximately 650 nm Output half-width 3-10 nm 4-6 nm 5 nm ± 1 nm Diameter of the light spot on the eye surface 6-12 mm 8-10 mm 9 mm ± 1 mm ocular output power 0.5-3.0 mW 1.0-2.5 mW 1.5±0.3 mW or 2.0±0.3 mW Target working distance 50-120 mm 60-90 mm Approximately 73 mm Distance between LED and first lens 0.5-5 mm Determined based on lens focal length and LED light-emitting surface. Approximately 1.74 mm Distance between the first lens and the second lens 10-40 mm Determined according to alignment and reshaping requirements Approximately 22.55 mm Distance between the second lens and the filter 0-10 mm 0-3 mm or close to the setting 0 mm or close to setting Filter cutoff depth OD3-OD4 OD4 Determined based on actual measurements Peak transmittance of filter No less than 60% No less than 80% Determined based on actual measurements Filter incident angle 0-10° 0-5° Determined based on actual optical path measurements

[0069] Key technical features: This system uses an LED non-laser light source to reduce light source coherence and speckle effect. A dual-lens collimation and shaping structure is constructed using a first lens and a second lens to collect, collimate, and shape the divergent red light emitted by the LED. The dual lenses ensure that the beam entering the narrowband red light filter is collimated or nearly collimated, controlling the filter's incident angle within 0-10°, preferably 0-5°.

[0070] This system uses a narrowband red light filter to filter the broadband red light from the LED, so that the optimal full width at half maximum (FWHM) of the output red light is 5nm ± 1nm.

[0071] This system forms a low-intensity red light spot with a preferred diameter of 9 mm ± 1 mm at the target ocular surface location. The output power at the target ocular surface location is preferably controlled at 1.5 ± 0.3 mW or 2.0 ± 0.3 mW. This system is used for low-intensity red light irradiation of the eye to help improve choroidal blood circulation and fundus microcirculation, and can serve as a core optical module in myopia control devices.

[0072] Working Principle: The original red light generated by the LED red light source is broadband divergent light. The first lens collects this divergent light, converging or collimating some of it towards the optical axis. The second lens further adjusts the beam propagation state, ensuring that the beam entering the narrowband red light filter has a smaller angular distribution. When the narrowband red light filter receives a collimated or nearly collimated beam, the difference in the incident angle received at different positions on the filter decreases, and the center wavelength drift and half-width at half-maximum broadening decrease accordingly. The red light filtered by the filter forms a low-intensity narrowband red light spot with stable diameter and controlled power at the target ocular surface.

[0073] This low-intensity narrow-spectrum red light enters the fundus region through the eye's refractive media and can be used to irradiate the retina, choroid, and related microcirculatory structures with low-intensity red light to help improve choroidal blood circulation and fundus microcirculation.

[0074] Example 2

[0075] This invention provides an application of the LED narrow-spectrum red light eye irradiation optical system in the preparation of an eye irradiation device for improving choroidal blood circulation. The low-intensity narrow-spectrum red light output by the system enters the fundus region through the eye's refractive medium, irradiating the retina and choroid region at a low intensity to help improve choroidal blood circulation and fundus microcirculation.

[0076] In summary, the LED narrow-spectrum red light ocular irradiation optical system for improving choroidal blood circulation proposed in this invention uses an LED non-laser red light source to replace the laser source, fundamentally reducing the coherence of the light source. Due to its high coherence, laser sources are prone to speckle effects in ocular irradiation scenarios, leading to uneven energy distribution in the fundus and posing a potential risk of tissue thermal damage. The low coherence of LED sources significantly reduces the speckle effect, resulting in a more uniform distribution of irradiation energy within the target area. Furthermore, LED sources offer advantages such as low cost, structural stability, a mature supply chain, and high public safety acceptance, making them more suitable for low-intensity red light ocular irradiation in home and long-term use scenarios.

[0077] This invention achieves narrowing of the spectral range of broadband red light from LEDs. The original full width at half maximum (FWHM) of ordinary LED red light is typically 20-40 nm, which is insufficient to directly meet the spectral purity requirements for low-intensity narrow-spectrum red light irradiation in the eye. This invention achieves narrowing of the output of broadband red light from LEDs through the synergistic cooperation of a dual-lens collimation and shaping structure consisting of a first lens and a second lens, and a narrow-band red light filter. First, the first lens collects and initially collimates the divergent light emitted from the LED. Then, the second lens further shapes the light to reduce the beam divergence angle, making the beam entering the narrow-band red light filter approximately collimated. Under collimated beam incident conditions, the narrow-band red light filter achieves optimal spectral filtering performance, with a cutoff depth reaching OD4 and a peak transmittance of no less than 80%. Ultimately, the FWHM of the output red light is stably compressed to 5 nm ± 1 nm, with the center wavelength maintained within the range of 645-655 nm.

[0078] The spectral transmission characteristics of narrowband red light filters are highly sensitive to the incident angle of the light beam. When the incident beam has a large angular distribution, the difference in incident angle received by different regions of the filter is significant, causing the effective center wavelength at different positions to shift. This shift, when superimposed, manifests as a center wavelength drift and full width at half maximum (FWHM) broadening in the overall output spectrum. This invention, through a dual-lens collimation and shaping structure, controls the incident angle of the light beam entering the filter within the range of 0°-10°, preferably within the range of 0°-5°. This minimizes the difference in incident angle received by different regions of the filter, effectively suppressing center wavelength drift and FWHM broadening, and ensuring the wavelength stability and spectral consistency of the output narrowband red light.

[0079] Ordinary LED light sources have a large divergence angle. Without effective collimation and shaping, the size of the light spot illuminating the target ocular surface fluctuates significantly with changes in working distance, making it difficult to ensure stable and controllable illumination area and power density. This invention uses a dual-lens collimation and shaping structure to precisely control the beam propagation state, combined with a light-shielding lens to stably fix the position of optical elements, and an ocular surface positioning structure to maintain consistency at the working distance. This results in a circular red light spot with a diameter of 9mm ± 1mm ​​at the target ocular surface, with the spot diameter remaining stable within the working distance range, making the ocular surface illumination area and power density more controllable.

[0080] This invention, through the cooperation of a power control module and an LED driving circuit, precisely controls the output power at the target ocular surface location within a low intensity range (0.5-3.0mW), preferably 1.5±0.3mW or 2.0±0.3mW. This power level ensures effective photobiological regulation of the retinal tissue while remaining well below the safe damage threshold for ocular tissue, thus balancing efficacy and safety.

[0081] The low-intensity narrow-spectrum red light (center wavelength 645-655nm, half-width at half-maximum approximately 5nm) output by this invention enters the fundus region through the ocular refractive media, providing low-intensity red light irradiation to the retina and choroidal microcirculatory structures. Based on the photobiological regulatory mechanism of red light on mitochondrial cytochrome C oxidase, this narrow-spectrum red light can promote the function of choroidal vascular endothelial cells, help improve choroidal blood circulation and fundus microcirculation, thereby playing a positive role in myopia prevention and control.

[0082] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; those skilled in the art can modify the technical solutions described in the foregoing embodiments, or make equivalent substitutions for some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An LED narrow-spectrum red light eye irradiation optical system for improving choroidal blood circulation, characterized in that, include: LED red light source, first lens, second lens, narrowband red light filter and light-shielding lens tube; The LED red light source is located at the beginning of the optical path and is used to generate original broadband divergent red light; The first lens is positioned after the LED red light source to collect and initially collimate the LED's diffused light. The second lens is disposed after the first lens and is used to further collimate and shape the beam after it has been initially collimated by the first lens, so as to control the beam divergence angle and the incident angle of the beam entering the narrow band red light filter. The narrowband red light filter is disposed after the second lens to filter the target red light band and cut off non-target bands so as to output narrowband red light. The light-shielding lens tube is used to cover and fix the LED red light source, the first lens, the second lens, and the narrow-band red light filter to reduce stray light and maintain the relative position stability of each optical element along the optical axis. The system also includes an ocular surface positioning structure set at the light-emitting end to keep the target ocular surface within a preset working distance range so as to form a narrow-band red light irradiation spot with a stable diameter at the target ocular surface position.

2. The LED narrow-spectrum red light eye illumination optical system according to claim 1, characterized in that, The first lens and the second lens constitute a dual-lens collimation and shaping structure, used to control the incident angle of the light beam entering the narrowband red light filter between 0° and 10°; and both the first lens and the second lens are convex lenses. That is, after being collimated and shaped by the first lens and the second lens, the incident angle of the light beam entering the narrowband red light filter is controlled within the range of 0-10°.

3. The LED narrow-spectrum red light eye illumination optical system according to claim 2, characterized in that, The incident angle of the beam is controlled between 0° and 5°.

4. The LED narrow-spectrum red light eye illumination optical system according to claim 1, characterized in that, The LED red light source is a non-laser source to reduce coherence and speckle effect.

5. The LED narrow-spectrum red light eye illumination optical system according to claim 2, characterized in that, The narrowband red light output by the filter has a center wavelength of 645-655 nm and an output half-width at half-maximum of 5 nm ± 1 nm.

6. The LED narrow-spectrum red light eye illumination optical system according to claim 1, characterized in that, The diameter of the red light spot formed at the target ocular surface location is 6-12 mm.

7. The LED narrow-spectrum red light eye illumination optical system according to claim 6, characterized in that, The diameter of the red light spot formed at the target ocular surface location is 9 mm ± 1 mm.

8. The LED narrow-spectrum red light eye illumination optical system according to claim 1, characterized in that, It also includes a power control module electrically connected to the LED red light source, used to control the output power of the LED red light source so that the ocular surface output power at the target ocular surface position is 0.5-3.0 mW.

9. The LED narrow-spectrum red light eye illumination optical system according to claim 1, characterized in that, The target working distance is 50-120 mm; the distance from the LED red light source to the first lens is 0.5-5 mm; the distance from the first lens to the second lens is 10-40 mm; and the distance from the second lens to the narrowband red light filter is 0-10 mm.

10. The LED narrow-spectrum red light eye illumination optical system according to claim 1, characterized in that, The narrowband red light filter has a cutoff depth of not less than OD3 and a peak transmittance of not less than 60%.

11. The LED narrow-spectrum red light eye illumination optical system according to claim 1, characterized in that, It also includes one or more of the following modules: a light power detection module for real-time detection of the output power of the LED red light source; an eye position detection module, located near the eye positioning area, for determining whether the eye is located at a preset irradiation position; a usage time control module for controlling the duration of a single irradiation; a left and right eye independent control module for independently controlling the light paths of the left and right eyes respectively; and a main control module, electrically connected to the power control module, light power detection module, eye position detection module, usage time control module, and left and right eye independent control module respectively, for coordinating and controlling the working status of each module.

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