Lens and glasses for blood oxygen test

Abstract

The utility model discloses a lens and glasses for a blood oxygen test, which can realize that the average reflectivity of the first optical film layer is less than or equal to 0.5% when the spectral wavelength is 400-1000nm through the design of the first optical film layer and the second optical film layer. The average transmittance of the second optical thin film layer at the wavelength of 420-640 nm and the wavelength of 900-1000 nm is larger than or equal to 95%. The lens can effectively improve the spectrum transmittance of a green light wave band with the wavelength ranging from 500 nm to 560 nm and the spectrum transmittance of a near-infrared short wave band with the wavelength ranging from 900 nm to 1000 nm, the energy transmission loss of green and near-infrared light wavelengths is reduced, and the blood oxygen testing accuracy is improved. And the influence of light brightness and darkness of a test environment on a blood oxygen test value can be effectively controlled.

Description

Technical Field

[0001] The utility model relates to the field of lenses, in particular to a lens and glasses for blood oxygen testing. Background Art

[0002] Blood oxygen saturation is an important indicator to measure the oxygen-carrying capacity of the body's blood and is also an important parameter reflecting the functions of the body's lung function, circulatory function, etc. Blood oxygen saturation, blood pressure, respiration, body temperature, and pulse are regarded as the five basic vital signs of life, and they are important pillars for maintaining normal life activities. A decrease in blood oxygen saturation will cause a series of harms to the health of the body, such as reduced lung function, increased risk of cardiovascular diseases, and adverse effects on the brain and body metabolism. Therefore, the blood oxygen level of patients is tested in daily physical examinations and the clinical diagnosis of many diseases.

[0003] Since oxyhemoglobin (HbO2) and reduced hemoglobin (Hb) in red blood cells in the blood have different absorption capacities for light. Therefore, the current blood oxygen testers on the market mainly test the contents of HbO2 and Hb in the human body through the reflection or transmission of light. The transmissive blood oxygen meter can only be used for relatively limited body parts, such as fingers, earlobes, etc., while the reflective blood oxygen meter can be placed at different positions on the whole body, and the blood oxygen saturation can be measured through a very small sensor. However, due to the problem of light transmission loss in the reflective blood oxygen meter, the accuracy of its blood oxygen test cannot be guaranteed. Summary of the Utility Model

[0004] The purpose of the utility model is to provide a blood oxygen test lens for a reflective blood oxygen meter, which has a high transmittance and low energy transmission loss in the short wavelength band of green light and near-infrared light, greatly improving the accuracy of reflective blood oxygen testing, and can achieve accurate blood oxygen testing without being affected by the brightness of light. At the same time, the lens proposed in the utility model also has a long service life and the ability of anti-fouling and wear resistance.

[0005] To achieve the above object, a first aspect of the present utility model provides a lens for blood oxygen testing. The lens includes a substrate, a first optical thin film layer disposed on the inner surface of the substrate, and a second optical thin film layer on the outer surface of the substrate. The side of the lens that directly receives the light from the light source in the use state is the outer surface, which is the side of the lens away from the human eye. Both the first optical thin film layer and the second optical thin film layer are composed of alternately stacked low refractive index film layers and high refractive index film layers. Among them, the refractive index of the high refractive index film layer is 1.85 - 2.80, and the refractive index of the low refractive index film layer is 1.35 - 1.50. The first optical thin film layer includes 9 layers of films. The first layer of film to the ninth layer of film from the inner surface of the substrate outwards are: a SiO2 layer of 1000 - 3000 angstroms, a Ti3O5 layer of 50 - 200 angstroms, a SiO2 layer of 300 - 800 angstroms, a Ti3O5 layer of 100 - 600 angstroms, a MgF2 layer of 50 - 300 angstroms, a Ti3O5 layer of 400 - 1200 angstroms, a MgF2 layer of 50 - 300 angstroms, a Ti3O5 layer of 100 - 500 angstroms, and a MgF2 layer of 800 - 2000 angstroms.

[0006] Further, the substrate is any one of glass, PC sheet, CR39 sheet, nylon sheet, and AC sheet.

[0007] Further, the material of the high refractive index film layer is Ti3O5, and the material of the low refractive index film layer is any one or both of SiO2 and MgF2.

[0008] Further, the second optical thin film layer includes 30 layers, and the Ti3O5 layer and the SiO2 layer are alternately stacked in sequence from the outer surface of the substrate outwards. Among them, the thickness of the Ti3O5 layer is 50 - 1500 angstroms, and the thickness of the SiO2 layer is 200 - 3000 angstroms.

[0009] Further, an anti - pollution and wear - resistant layer is stacked outside the first optical thin film layer, and the thickness of the anti - pollution and wear - resistant layer is 50 - 150 angstroms.

[0010] Further, a high - hardness wear - resistant layer is stacked outside the second optical thin film layer, and the thickness of the high - hardness wear - resistant layer is 100 - 300 angstroms.

[0011] A second aspect of the present utility model provides a blood oxygen testing glasses, including the lens for blood oxygen testing proposed in the first aspect of the present utility model.

[0012] The lens for blood oxygen testing proposed in the present utility model can achieve an average reflectivity of the first optical thin film layer of ≤ 0.5% in the spectral wavelength range of 400 - 1000 nm through the design of the film layers of the first optical thin film layer and the second optical thin film layer. The average transmittance of the second optical thin film layer is ≥ 95% in the spectral wavelength ranges of 420 - 640 nm and 900 - 1000 nm; when the spectral wavelength is 600 - 700 nm, 50% T is between the wavelengths of 640 - 660 nm; when the spectral wavelength is 800 - 900 nm, 50% T is between the wavelengths of 865 - 885 nm; and the average transmittance of the spectral wavelength in the range of 700 - 800 nm is ≤ 1%.

[0013] The blood oxygen testing lens in the present utility model can effectively improve the spectral transmittance of the lens in the green light band with a wavelength of 500 - 560 nm and the near - infrared short - wave band with a wavelength of 900 - 1000 nm by depositing the first optical thin film layer with low reflectivity and high transmittance and the second optical thin film layer on the inner and outer surfaces of the substrate, reduce the energy transmission loss of green and near - infrared wavelengths, and improve the accuracy of blood oxygen testing. It can also effectively control the influence of the brightness and darkness of ambient light during the testing process on the blood oxygen testing value.

[0014] The average reflectivity of the first optical thin film layer in the 400 - 1000 nm band is ≤ 0.5%, enabling the lens to effectively transmit green light and near - infrared short - wave bands even under relatively dim light conditions. The second optical thin film layer can transmit green light and near - infrared short - wave bands under relatively bright light conditions, and at the same time has a very low transmittance for light with a wavelength in the range of 700 - 800 nm, which can avoid the interference of stray light on the accuracy of blood oxygen detection in a well - lit environment.

[0015] The second optical thin film layer is set such that 50% T for the spectral wavelength of 600 - 700 nm is between the wavelengths of 640 - 660 nm; and 50% T for the spectral wavelength of 800 - 900 nm is between the wavelengths of 865 - 885 nm. This can reduce the loss of light energy transmission, improve the transmission efficiency, and make the detection result more accurate.

[0016] At the same time, an anti - fouling and wear - resistant layer and a high - hardness wear - resistant layer are respectively set on the surfaces of the first optical thin film layer and the second optical thin film layer to protect the lens from damage and improve its service life. The thickness of the anti - fouling and wear - resistant layer is set to 50 - 150 angstroms, and the thickness of the high - hardness wear - resistant layer is set to 100 - 300 angstroms, avoiding the problems of loss of light wave transmission efficiency caused by too thick film layers and poor protection effect due to too thin film layers. Description of the Drawings

[0017] Figure 1 It is a schematic structural diagram of the lens in the present utility model;

[0018] Figure 2 This is the reflection spectrum diagram of the first optical thin film layer in the embodiment of the present utility model;

[0019] Figure 3 This is the transmittance spectrum diagram of the second optical thin film layer in the embodiment of the present utility model. Detailed implementation manners

[0020] The embodiments of the present utility model will be described in detail below. The examples of the embodiments are shown in the accompanying drawings, where the same or similar reference numerals represent the same or similar elements or elements with the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to explain the present utility model, and should not be construed as a limitation of the present utility model. For those technical or conditions not specified in the embodiments, they shall be carried out according to the technologies or conditions described in the literature in this field or according to the product specifications. The reagents or instruments used without indicating the manufacturer can be obtained as conventional products through commercial purchase. In the following embodiments, unless otherwise specified, "%" refers to weight percentage.

[0021] The materials used for the anti-fouling and wear-resistant layer (DON-SH-450) and the high-hardness wear-resistant layer (DON-9045) in the present utility model are all commercially available materials and can be selected according to requirements.

[0022] The water contact angle test method in the present utility model is as follows: Use 0000 steel wool with a load of 1000 grams to rub the surface of the lens to be tested for 2500 friction cycles, then clean and dry the surface of the lens to ensure that no impurities and dirt affect the test results. Drop ultrapure water on the rubbed surface of the lens through a syringe, record the shape of the liquid drop on the surface with a microscope, and measure the angle between the liquid drop and the contact line on the surface with a contact angle measuring instrument to obtain the water contact angle.

[0023] The hardness test method in the present utility model is: Calculate the hardness value of the lens through a hardness tester.

[0024] The first optical thin film layer of the present utility model includes 9 thin films, from the first thin film to the ninth thin film starting from the inner surface of the substrate; the first thin film is a SiO2 layer with a thickness of 1000 - 3000 angstroms, not limited to 1000 angstroms, 1100 angstroms, 1200 angstroms, 1300 angstroms, 1400 angstroms, 1500 angstroms, 1600 angstroms, 1700 angstroms, 1800 angstroms, 1900 angstroms, 2000 angstroms, 2100 angstroms, 2200 angstroms, 2300 angstroms, 2400 angstroms, 2500 angstroms, 2600 angstroms, 2700 angstroms, 2800 angstroms, 2900 angstroms, 3000 angstroms; the second thin film is a Ti3O5 layer with a thickness of 50 - 200 angstroms, not limited to 50 angstroms, 60 angstroms, 70 angstroms, 80 angstroms, 90 angstroms, 100 angstroms, 110 angstroms, 120 angstroms, 130 angstroms, 140 angstroms, 150 angstroms, 160 angstroms, 170 angstroms, 180 angstroms, 190 angstroms, 200 angstroms; the third thin film is a SiO2 layer with a thickness of 300 - 800 angstroms, not limited to 300 angstroms, 310 angstroms, 320 angstroms, 330 angstroms, 340 angstroms, 350 angstroms, 360 angstroms, 370 angstroms, 380 angstroms, 390 angstroms, 400 angstroms, 410 angstroms, 420 angstroms, 430 angstroms, 440 angstroms, 450 angstroms, 460 angstroms, 470 angstroms, 480 angstroms, 490 angstroms, 500 angstroms, 510 angstroms, 520 angstroms, 530 angstroms, 540 angstroms, 550 angstroms, 560 angstroms, 570 angstroms, 580 angstroms, 590 angstroms, 600 angstroms, 610 angstroms, 620 angstroms, 630 angstroms, 640 angstroms, 650 angstroms, 660 angstroms, 670 angstroms, 680 angstroms, 690 angstroms, 700 angstroms, 710 angstroms, 720 angstroms, 730 angstroms, 740 angstroms, 750 angstroms, 760 angstroms, 770 angstroms, 780 angstroms, 790 angstroms, 800 angstroms;The fourth layer of the thin film is a Ti3O5 layer with a thickness of 100 - 600 angstroms, not limited to 100 angstroms, 110 angstroms, 120 angstroms, 130 angstroms, 140 angstroms, 150 angstroms, 160 angstroms, 170 angstroms, 180 angstroms, 190 angstroms, 200 angstroms, 210 angstroms, 220 angstroms, 230 angstroms, 240 angstroms, 250 angstroms, 260 angstroms, 270 angstroms, 280 angstroms, 290 angstroms, 300 angstroms, 310 angstroms, 320 angstroms, 330 angstroms, 340 angstroms, 350 angstroms, 360 angstroms, 370 angstroms, 380 angstroms, 390 angstroms, 400 angstroms, 410 angstroms, 420 angstroms, 430 angstroms, 440 angstroms, 450 angstroms, 460 angstroms, 470 angstroms, 480 angstroms, 490 angstroms, 500 angstroms, 510 angstroms, 520 angstroms, 530 angstroms, 540 angstroms, 550 angstroms, 560 angstroms, 570 angstroms, 580 angstroms, 590 angstroms, 600 angstroms, 610 angstroms, 620 angstroms, 630 angstroms, 640 angstroms, 650 angstroms, 660 angstroms, 670 angstroms, 680 angstroms, 690 angstroms, 700 angstroms, 710 angstroms, 720 angstroms, 730 angstroms, 740 angstroms, 750 angstroms, 760 angstroms, 770 angstroms, 780 angstroms, 790 angstroms; The fifth layer of the thin film is an MgF2 layer with a thickness of 50 - 300 angstroms, not limited to 50 angstroms, 60 angstroms, 70 angstroms, 80 angstroms, 90 angstroms, 100 angstroms, 110 angstroms, 120 angstroms, 130 angstroms, 140 angstroms, 150 angstroms, 160 angstroms, 170 angstroms, 180 angstroms, 190 angstroms, 200 angstroms, 210 angstroms, 220 angstroms, 230 angstroms, 240 angstroms, 250 angstroms, 260 angstroms, 270 angstroms, 280 angstroms, 290 angstroms, 300 angstroms; The sixth layer of the thin film is a Ti3O5 layer with a thickness of 400 - 1200 angstroms, not limited to 400 angstroms, 450 angstroms, 500 angstroms, 550 angstroms, 600 angstroms, 650 angstroms, 700 angstroms, 750 angstroms, 800 angstroms, 850 angstroms, 900 angstroms, 950 angstroms, 1000 angstroms, 1050 angstroms, 1100 angstroms, 1150 angstroms, 1200 angstroms; The seventh layer of the thin film is an MgF2 layer with a thickness of 50 - 300 angstroms, not limited to 50 angstroms, 60 angstroms, 70 angstroms, 80 angstroms, 90 angstroms, 100 angstroms, 110 angstroms, 120 angstroms, 130 angstroms, 140 angstroms, 150 angstroms, 160 angstroms, 170 angstroms, 180 angstroms, 190 angstroms, 200 angstroms, 210 angstroms, 220 angstroms, 230 angstroms, 240 angstroms, 250 angstroms, 260 angstroms, 270 angstroms, 280 angstroms, 290 angstroms, 300 angstroms;The eighth layer of the film is a Ti3O5 layer with a thickness of 100 - 500 angstroms, not limited to 100 angstroms, 110 angstroms, 120 angstroms, 130 angstroms, 140 angstroms, 150 angstroms, 160 angstroms, 170 angstroms, 180 angstroms, 190 angstroms, 200 angstroms, 210 angstroms, 220 angstroms, 230 angstroms, 240 angstroms, 250 angstroms, 260 angstroms, 270 angstroms, 280 angstroms, 290 angstroms, 300 angstroms, 310 angstroms, 320 angstroms, 330 angstroms, 340 angstroms, 350 angstroms, 360 angstroms, 370 angstroms, 380 angstroms, 390 angstroms, 400 angstroms, 410 angstroms, 420 angstroms, 430 angstroms, 440 angstroms, 450 angstroms, 460 angstroms, 470 angstroms, 480 angstroms, 490 angstroms, 500 angstroms; The ninth layer of the film is a MgF2 layer with a thickness of 800 - 2000 angstroms, not limited to 800 angstroms, 900 angstroms, 1000 angstroms, 1100 angstroms, 1200 angstroms, 1300 angstroms, 1400 angstroms, 1500 angstroms, 1600 angstroms, 1700 angstroms, 1800 angstroms, 1900 angstroms, 2000 angstroms.;

[0025] The second optical film layer includes 30 layers, and the Ti3O5 layer and the SiO2 layer are sequentially stacked outward from the outer surface of the substrate. Among them, the thickness of the Ti3O5 layer is 50 - 1500 angstroms, not limited to 50 angstroms, 100 angstroms, 150 angstroms, 200 angstroms, 250 angstroms, 300 angstroms, 350 angstroms, 400 angstroms, 450 angstroms, 500 angstroms, 550 angstroms, 600 angstroms, 650 angstroms, 700 angstroms, 750 angstroms, 800 angstroms, 850 angstroms, 900 angstroms, 950 angstroms, 1000 angstroms, 1050 angstroms, 1100 angstroms, 1150 angstroms, 1200 angstroms, 1250 angstroms, 1300 angstroms, 1350 angstroms, 1400 angstroms, 1450 angstroms, 1500 angstroms; The thickness of the SiO2 layer is 200 - 3000 angstroms, 200 angstroms, 300 angstroms, 400 angstroms, 500 angstroms, 600 angstroms, 700 angstroms, 800 angstroms, 900 angstroms, 1000 angstroms, 1100 angstroms, 1200 angstroms, 1300 angstroms, 1400 angstroms, 1500 angstroms, 1600 angstroms, 1700 angstroms, 1800 angstroms, 1900 angstroms, 2000 angstroms, 2100 angstroms, 2200 angstroms, 2300 angstroms, 2400 angstroms, 2500 angstroms, 2600 angstroms, 2700 angstroms, 2800 angstroms, 2900 angstroms, 3000 angstroms.

[0026] The lens structure in this embodiment is as Figure 1As shown, the lens includes a substrate D1, a first optical thin film layer D2 provided on the inner surface of the substrate D1, a second optical thin film layer D3 on the outer surface of the substrate D1, an anti-fouling and wear-resistant layer D4 superimposed on the outside of the first optical thin film layer D2, and a high-hardness wear-resistant layer D5 superimposed on the outside of the second optical thin film layer D3.

[0027] The first optical thin film layer D2 includes 9 layers of thin films. The first layer of thin film to the ninth layer of thin film from the inner surface of the substrate D1 outwards are in turn: a SiO2 layer of 2100 angstroms, a Ti3O5 layer of 110 angstroms, a SiO2 layer of 500 angstroms, a Ti3O5 layer of 350 angstroms, a MgF2 layer of 150 angstroms, a Ti3O5 layer of 850 angstroms, a MgF2 layer of 200 angstroms, a Ti3O5 layer of 300 angstroms, and a MgF2 layer of 1100 angstroms.

[0028] The second optical thin film layer D3 includes 30 layers, and Ti3O5 layers and SiO2 layers are alternately superimposed in turn from the outer surface of the substrate D1 outwards. Among them, the thickness of the Ti3O5 layer is 500 angstroms, and the thickness of the SiO2 layer is 1300 angstroms. The thickness of the anti-fouling and wear-resistant layer D4 is 100 angstroms, and the thickness of the high-hardness wear-resistant layer D5 is 200 angstroms.

[0029] Figure 2 This is the reflection spectrum diagram of the first optical thin film layer in Embodiment 1 of the present invention. The abscissa is the wavelength, and the ordinate is the reflectivity. As Figure 2 As shown in and Table 1, the reflectivity of the first optical thin film layer D2 in this embodiment at a wavelength of 400 - 1000 nm is 0.38%.

[0030] Figure 3 This is the transmittance spectrum diagram of the second optical thin film layer in the embodiment of the present invention. The abscissa is the wavelength, and the ordinate is the transmittance. As Figure 3 As shown in and Table 2, the average transmittance of the obtained second optical thin film layer D3 in this embodiment at a wavelength of 420 - 640 nm is 99.190%, the average transmittance at a wavelength of 900 - 1000 nm is 98.900%, and the average transmittance at a wavelength of 700 - 800 nm is 0.095%. The 50% T at a wavelength of 600 - 700 nm is between 640 - 670 nm, and the 50% T at a wavelength of 800 - 900 nm is between 860 nm - 890 nm.

[0031] The hardness of the high-hardness wear-resistant layer D5 can reach 8H. With a 1000-gram load of 0000 steel wool and 2500 friction cycles, the measured water contact angle is greater than 108.62. Therefore, the lens in this embodiment has strong anti-fouling ability and service life.

[0032] Table 1. Reflectivity Table of the First Optical Thin Film Layer

[0033]

[0034]

[0035] Table 2. Transmittance Table of the Second Optical Thin Film Layer

[0036]

[0037]

[0038] In other embodiments, the anti-fouling and wear-resistant layer and the high-hardness wear-resistant layer may not be provided. The lens structure includes a first optical thin film layer provided on the inner surface of the substrate and a second optical thin film layer provided on the outer surface of the substrate, and the lens also has lossless propagation of light energy.

[0039] Comparative Example 1:

[0040] The lens in Comparative Example 1 includes a substrate, a first optical thin film layer provided on the inner surface of the substrate, a second optical thin film layer provided on the outer surface of the substrate, an anti-fouling and wear-resistant layer stacked outside the first optical thin film layer, and a high-hardness wear-resistant layer stacked outside the second optical thin film layer.

[0041] The first optical thin film layer includes 9 layers of thin films. The first layer of thin film to the ninth layer of thin film from the inner surface of the substrate outwards are: an SiO2 layer of 800 angstroms, a Ti3O5 layer of 300 angstroms, an SiO2 layer of 200 angstroms, a Ti3O5 layer of 800 angstroms, an MgF2 layer of 500 angstroms, a Ti3O5 layer of 200 angstroms, an MgF2 layer of 500 angstroms, a Ti3O5 layer of 800 angstroms, and an MgF2 layer of 600 angstroms.

[0042] The second optical thin film layer includes 30 layers, and a Ti3O5 layer and an SiO2 layer are stacked in sequence from the outer surface of the substrate outwards. Among them, the thickness of the Ti3O5 layer is 2000 angstroms, and the thickness of the SiO2 layer is 3500 angstroms.

[0043] The thickness of the anti-fouling and wear-resistant layer is 40 angstroms, and the thickness of the high-hardness wear-resistant layer is 50 angstroms.

[0044] The average transmittance of the second optical thin film layer in this embodiment at wavelengths of 420 nm - 640 nm and 900 - 1000 nm is 67.4530% and 65.1995% respectively, and the average transmittance at wavelengths of 700 - 800 nm is 92.1542%.

[0045] The reflectance of the first optical thin film layer at wavelengths of 400 - 1000 nm is 23.924%.

[0046] The hardness of the high-hardness wear-resistant layer can reach 5H. Using 0000 steel wool with a load of 1000 grams and performing 2500 friction cycles, the measured water contact angle is 80.42.

[0047] Compared with the lens in Comparative Example 1, the reflectivity of the first optical thin film layer in this Example at wavelengths of 400 - 1000 nm is 0.38%, which is much lower than that of the first optical thin film layer in Comparative Example 1, and a better test effect can be achieved even in the case of insufficient ambient light. Compared with Comparative Example 1, the average transmittance of the second optical thin film layer in this Example at wavelengths of 420 nm - 640 nm and 900 - 1000 nm is greater than 95%, and the average transmittance at wavelengths of 700 - 800 nm is 0.095%. The second optical thin film layer proposed in this Example can better transmit light without being affected by stray light in other wavelength bands under the condition of relatively bright ambient light.

[0048] At the same time, the lens in the Example has better anti-friction and anti-fouling capabilities, so its service life is longer.

[0049] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention without departing from the principles and purposes of the present invention.

Claims

1. A lens for blood oxygen testing, characterized in that, The lens comprises a substrate, a first optical film layer arranged on the inner surface of the substrate, and a second optical film layer on the outer surface of the substrate. The side of the lens that directly receives light from the light source when in use, that is, the side of the lens away from the human eye, is the outer surface; the first optical film layer and the second optical film layer are both composed of low-refractive index film layers and high-refractive index film layers alternately stacked in sequence, wherein the refractive index of the high-refractive index film layer is 1.85-2.80, and the refractive index of the low-refractive index film layer is 1.35-1.50; the first optical film layer comprises 9 layers The thin films, from the first layer to the ninth layer from the inner surface of the substrate to the outside, are: 1000-3000 angstroms SiO2 layer, 50-200 angstroms Ti3O5 layer, 300-800 angstroms SiO2 layer, 100-600 angstroms Ti3O5 layer, 50-300 angstroms MgF2 layer, 400-1200 angstroms Ti3O5 layer, 50-300 angstroms MgF2 layer, 100-500 angstroms Ti3O5 layer, and 800-2000 angstroms MgF2 layer.

2. The lens for blood oxygen measurement according to claim 1, characterized in that The substrate is any one of glass, PC sheet, CR39 sheet, nylon sheet and AC sheet.

3. The lens for blood oxygen testing according to claim 1, characterized in that, The material of the high refractive index film layer is Ti3O5, and the material of the low refractive index film layer is any one of SiO2 and MgF2.

4. The lens for blood oxygen testing according to claim 1, characterized in that: The second optical thin film layer includes 30 layers, which are Ti3O5 layers and SiO2 layers stacked in sequence from the outer surface of the substrate outward, wherein the thickness of the Ti3O5 layer is 50-1500 angstroms, and the thickness of the SiO2 layer is 200-3000 angstroms.

5. The lens for blood oxygen measurement according to claim 1, characterized in that, An antifouling and wear-resistant layer is superimposed on the first optical film layer, and the thickness of the antifouling and wear-resistant layer is 50-150 angstroms.

6. The lens for blood oxygen testing according to claim 1, wherein The second optical film layer is superimposed with a high-hardness wear-resistant layer, and the thickness of the high-hardness wear-resistant layer is 100-300 angstroms.

7. A blood oxygen test glasses, characterized in that, A lens for blood oxygen testing according to any one of claims 1 to 6.

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