An ocular parameter measuring instrument

Abstract

The application provides an eye parameter measuring instrument, comprising a wavefront pre-compensation device, a wavefront aberration measuring device and a corneal topography measuring device; the wavefront pre-compensation device comprises a compensation light source, a collimating lens and a first 4f system; the wavefront aberration measuring device comprises a second 4f system, a first light splitting element and a wavefront aberration instrument; the corneal topography measuring device comprises a Placido disc structure, a third 4f system, a second light splitting element and an image acquisition element; the Placido disc structure faces the eye of a measured person; the light paths of the first 4f system and the third 4f system intersect at the second light splitting element; and the light paths of the second 4f system and the third 4f system intersect at the first light splitting element. The wavefront aberration measuring device and the corneal topography measuring device are arranged, so that the wavefront aberration and the corneal topography of the eye can be measured simultaneously in one inspection, the inspection times of the measured person are reduced, and accidental errors caused by multiple inspections are avoided.

Description

Technical Field

[0001] This application belongs to the field of ophthalmic medical device technology, and more specifically, relates to an instrument for measuring ocular parameters. Background Technology

[0002] The cornea is the transparent, anterior part of the eye, located in the anterior 1 / 6 of the eyeball wall. It is an avascular, transparent fibrous membrane. It covers the iris, pupil, and anterior chamber, providing most of the eye's refractive power and playing a vital role in maintaining the integrity of the eyeball, protecting it, and preserving vision. The corneal radius of curvature is an important parameter of the cornea. Within the circular area near the pupillary region of the central cornea, due to its near-spherical shape, the radius of curvature is approximately equal at all points. However, in the intermediate and peripheral corneas outside the central area, the cornea is flatter, and the radius of curvature is not equal at all points.

[0003] Corneal topography is a common method for describing the local topography of the corneal surface. It reflects the shape of various points on the corneal surface, allowing the determination of the radius of curvature of different points on the cornea and assessing overall changes in the corneal surface. A corneal topography instrument is used to generate corneal topographic maps; currently, the most widely used is the Placido corneal topography instrument.

[0004] Placido consists of a set of concentric rings (usually 16, 32, or 36). The disc is placed in front of the subject's eye, projecting onto the corneal surface. A CCD collects the reflected image of the cornea, allowing for the calculation of corneal morphology information and the determination of corneal lesions. If the corneal surface is normal, the rings are regularly spaced concentric rings; if the corneal surface morphology is abnormal, the distance between the rings in the reflected image is irregular. For the collected ring image, the smaller the spacing between the concentric rings, the steeper the cornea; the larger the spacing, the flatter the cornea.

[0005] In visual optics, defocus and astigmatism, two optical defects that can be corrected by spherical lenses, are called lower-order aberrations. However, besides defocus and astigmatism, the eye also has other higher-order aberrations. These higher-order aberrations cannot be corrected by wearing lenses and will affect the image quality of the eye to some extent. Eye aberrations are mainly affected by two factors: the cornea and the lens. Corneal aberrations can be calculated using Placido corneal topography, but intraocular aberrations cannot be analyzed from corneal topography. The SH (Shack-Hartmann) wavefront aberrometer is currently a commonly used principle for detecting ocular wavefront aberrations. It features simple structure, fast measurement speed, and strong vibration resistance. It can record wavefront changes in real time and has wide applications in adaptive optics, ocular aberration detection, optical element surface shape detection, and optical system wavefront aberration detection.

[0006] However, the SH wavefront aberrometer can only measure the wavefront aberration of active light sources. Therefore, during the measurement, a collimated laser light source is used to illuminate the eye. The collimated laser light incident on the eye forms a light spot on the retina. After receiving the reflected light from the retina, this light spot propagates in all directions as a point light source. Most of the light is absorbed by the inner wall of the eyeball, and a small portion of the light carries wavefront information and is emitted. The eye aberration can be measured based on the reflected image.

[0007] The overall aberration data of the eye can be obtained by measuring and calculating the Placido corneal topography and the measurement results of the SH wavefront aberrometer. However, random errors are inevitable from multiple measurements by the two instruments, and long-term measurements will also affect the final aberration data of the eye. Summary of the Invention

[0008] The purpose of this application is to provide an eye parameter measuring instrument to solve the technical problem in the prior art that eye parameters need to be measured multiple times by multiple instruments, resulting in random errors.

[0009] To achieve the above objectives, the technical solution adopted in this application is as follows: An eye parameter measuring instrument is provided, comprising a wavefront pre-compensation device, a wavefront aberration measuring device, and a corneal topography measuring device; the wavefront pre-compensation device comprises a compensation light source, a collimating lens, and a first 4f system arranged sequentially; the wavefront aberration measuring device comprises a second 4f system, a first beam splitter, and a wavefront aberrometer arranged sequentially; the corneal topography measuring device comprises a Placido disc structure, a third 4f system, a second beam splitter, and an image acquisition element arranged sequentially; the Placido disc structure faces the subject's eye; wherein the optical paths of the first 4f system and the third 4f system intersect at the second beam splitter; the optical paths of the second 4f system and the third 4f system intersect at the first beam splitter.

[0010] Furthermore, the compensation light source includes a first light source, a second light source, and a coupling optical fiber. The beam emitted by the first light source and the beam emitted by the second light source are combined into a single beam through the coupling optical fiber. The first light source is used to provide a light source for the wavefront aberration measurement device. The second light source is used to determine whether the eye position of the subject is correct.

[0011] Furthermore, the first 4f system includes a first front achromatic lens and a first rear achromatic lens arranged sequentially.

[0012] Furthermore, the second beam splitter is disposed between the first front achromatic lens and the first rear achromatic lens.

[0013] Furthermore, the second 4f system includes a second front achromatic lens and a first rear achromatic lens, with the first beam splitter and the second beam splitter sequentially disposed between the second front achromatic lens and the first rear achromatic lens.

[0014] Furthermore, the eye parameter measuring instrument also includes a first aperture, which is disposed between the first beam splitter and the second beam splitter, or the first aperture is disposed between the second front achromatic lens and the first beam splitter.

[0015] As another preferred embodiment, the second beam splitter is disposed between the first rear achromatic lens and the Placido disc structure.

[0016] As another preferred embodiment, the second 4f system includes a second front achromatic lens and a second rear achromatic lens, with the second beam splitter disposed between the second rear achromatic lens and the Placido disc structure; the first beam splitter is disposed between the second front achromatic lens and the second rear achromatic lens.

[0017] As another preferred embodiment, the eye parameter measuring instrument further includes a first aperture, which is disposed between the second front achromatic lens and the first beam splitter; or, the first aperture is disposed between the first beam splitter and the second rear achromatic lens.

[0018] Furthermore, the third 4f system includes a third front achromatic lens and a first rear achromatic lens, with the first beam splitter and the second beam splitter sequentially disposed between the third front achromatic lens and the first rear achromatic lens.

[0019] As another preferred embodiment, the third 4f system includes a third front achromatic lens and a second rear achromatic lens, with the second beam splitter disposed between the second rear achromatic lens and the Placido disc structure; the first beam splitter is disposed between the third front achromatic lens and the second rear achromatic lens.

[0020] Furthermore, the eye parameter measuring instrument also includes a second aperture, which is disposed between the third front achromatic lens and the first beam splitter.

[0021] Furthermore, the eye parameter measuring instrument also includes a first bandpass filter, which is disposed between the wavefront aberrometer and the third front achromatic lens.

[0022] Furthermore, the eye parameter measuring instrument also includes a second bandpass filter, which is disposed between the image acquisition element and the second front achromatic lens.

[0023] Furthermore, the Placido disc structure includes an illumination unit.

[0024] The beneficial effects of the ocular parameter measuring instrument provided in this application are as follows:

[0025] (1) Compared with the prior art, in this application, by setting up a wavefront pre-compensation device, a wavefront aberration measurement device and a corneal topography measurement device, the wavefront aberration and corneal topography of the eye can be measured simultaneously in one examination, reducing the number of examinations for the examinee and avoiding random errors caused by multiple examinations.

[0026] (2) Compared with the prior art, the present application integrates wavefront aberration and corneal topography measurements, which can obtain comprehensive data in one examination, reducing the number of examinations, improving examination efficiency, reducing patient waiting time and discomfort, and enhancing the overall medical experience.

[0027] (3) Compared with the prior art, in this application, by introducing the first 4f system, the second 4f system and the third 4f system, not only is optical distortion effectively reduced and the stability and reliability of the system improved, but also the complex optical components are reduced, the overall structure is simplified, thereby reducing the overall manufacturing cost and improving production efficiency.

[0028] (4) Compared with the prior art, in this application, by introducing a third 4f system into the corneal topography measurement device, the consistency of the magnification of the Placido disc structure is ensured, making the measurement results of the corneal topography map more accurate. In addition, the measurement results of wavefront aberration can be used as a supplement to corneal topography, further improving the accuracy of the measurement.

[0029] (5) Compared with the prior art, the eye parameter measuring instrument of this application has strong adaptability. The lens combination in the first 4f system, the second 4f system and the third 4f system, as well as the number of rings of the Placido disc structure, can be adjusted according to the specific situation of the examinee to adapt to examinees with different corneal sizes, thereby improving the applicability and flexibility of the instrument. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0031] Figure 1 A schematic diagram of the structure of the eye parameter measuring instrument provided in the embodiments of this application. Figure 1 ;

[0032] Figure 2 A schematic diagram of the structure of the eye parameter measuring instrument provided in the embodiments of this application. Figure 2 ;

[0033] Figure 3 A schematic diagram of the structure of the eye parameter measuring instrument provided in the embodiments of this application. Figure 3 ;

[0034] Figure 4 A schematic diagram of the structure of the eye parameter measuring instrument provided in the embodiments of this application. Figure 4 ;

[0035] The following are the labeling elements in the figure:

[0036] 101-First light source; 102-Second light source; 103-Coupled optical fiber; 104-Collimating lens; 105-First front achromatic lens; 106-First rear achromatic lens;

[0037] 201-Second beam splitter; 202-Second rear achromatic lens; 203-First beam splitter; 204-First aperture; 205-Second front achromatic lens; 206-Second bandpass filter; 207-Image acquisition element;

[0038] 301 - Second aperture; 302 - Third front achromatic lens; 303 - First bandpass filter; 304 - Wavefront aberrometer;

[0039] 401-Placido disc structure. Detailed Implementation

[0040] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.

[0041] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.

[0042] It should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0043] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0044] Please refer to the following: Figures 1 to 4 The ocular parameter measuring instrument provided in this application embodiment will now be described. This ocular parameter measuring instrument includes a wavefront pre-compensation device, a wavefront aberration measuring device, and a corneal topography measuring device. The wavefront pre-compensation device includes a compensation light source, a collimating lens 104, and a first 4f system arranged sequentially. The wavefront aberration measuring device includes a second 4f system, a first beam splitter 203, and a wavefront aberrometer 304 arranged sequentially. The corneal topography measuring device includes a Placido disc structure 401, a third 4f system, a second beam splitter 201, and an image acquisition element 207 arranged sequentially. The Placido disc structure 401 faces the subject's eye. The optical paths of the first and third 4f systems intersect at the second beam splitter 201; the optical paths of the second and third 4f systems intersect at the first beam splitter 203.

[0045] Compared with the prior art, the ocular parameter measuring instrument provided in this application, by setting up a wavefront pre-compensation device, a wavefront aberration measuring device and a corneal topography measuring device, can simultaneously measure the wavefront aberration and corneal topography of the eye in one examination, reducing the number of examinations for the examinee and avoiding random errors caused by multiple examinations.

[0046] In this embodiment, wavefront aberration and corneal topography measurements are integrated, allowing for comprehensive data to be obtained in a single examination. This reduces the number of examinations, improves examination efficiency, reduces patient waiting time and discomfort, and enhances the overall medical experience.

[0047] In this embodiment, by introducing a first 4f system, a second 4f system, and a third 4f system, not only is optical distortion effectively reduced and the stability and reliability of the system improved, but also complex optical components are reduced, the overall structure is simplified, thereby reducing the overall manufacturing cost and improving production efficiency.

[0048] In this embodiment, by introducing a third 4f system into the corneal topography measurement device, the magnification consistency of the Placidodisc structure 401 is ensured, making the measurement results of the corneal topography map more accurate. Furthermore, the wavefront aberration measurement results can supplement the corneal topography measurement, further improving the accuracy of the measurement.

[0049] The ocular parameter measuring instrument of this application embodiment has strong adaptability. The lens combinations in the first 4f system, the second 4f system and the third 4f system, as well as the number of rings in the Placido disc structure 401, can be adjusted according to the specific situation of the examinee to adapt to examinees with different corneal sizes, thereby improving the applicability and flexibility of the instrument.

[0050] In essence, a 4f system utilizes two lenses and the characteristics of optical Fourier transform to achieve spatial frequency modulation and analysis. The name "4f" comes from its structure. If the focal length f1 of lens L1 is equal to the focal length f2 of lens L2, the total system distance is 4f, which is a standard 4f system, where the light field areas on the image plane and object plane are in a 1:1 ratio. If the focal lengths of L1 and L2 are different, the system functions the same as a standard 4f system, except that the scaling ratio of the light field size (horizontal and vertical directions) on the image plane is f2:f1 compared to the standard 4f system.

[0051] In one embodiment of this application, please refer to the following: Figures 1 to 4 The compensation light source includes a first light source 101, a second light source 102, and a coupling fiber 103. The light beam emitted by the first light source 101 and the light beam emitted by the second light source 102 are combined into a single light beam through the coupling fiber 103. The first light source 101 is used to provide a light source for the wavefront aberration measurement device. The second light source 102 is used to determine whether the eye position of the subject is correct.

[0052] In this embodiment, the first light source 101 is an SLED, and the wavelength of the light emitted by the SLED is 840nm. The second light source 102 is an LED, and the wavelength of the light emitted by the LED is 630nm. The 630nm beam is a collimated beam. The collimating lens 104 is used to adjust the beam synthesized by the coupling fiber 103 into a straight beam.

[0053] In one embodiment of this application, please refer to the following: Figures 1 to 4 The first 4f system includes a first front achromatic lens 105 and a first rear achromatic lens 106 arranged sequentially.

[0054] In this embodiment, the first 4f system is used to increase the peak power density of the emitted laser and reduce beam divergence; the first front achromatic lens 105 and the first rear achromatic lens 106 can reduce imaging distortion and improve the stability of light propagation; wherein, the focal length of the first front achromatic lens 105 is f1 = 25cm, and the focal length of the first rear achromatic lens 106 is f2 = 12.5cm.

[0055] In one embodiment of this application, please refer to the following: Figure 3 and Figure 4 The second beam splitter 201 is disposed between the first front achromatic lens 105 and the first rear achromatic lens 106.

[0056] In this embodiment, the second beam splitter 201 splits the beam passing through the first 4f system. One portion of the beam continues along its original path to the wavefront aberration measurement device, while the other portion is guided to the corneal topography measurement device. This design allows for simultaneous measurement of wavefront aberration and corneal topography, improving measurement efficiency.

[0057] In this embodiment, the second beam-splitting element 201 is a beam splitter with dimensions of 32*60mm and a beam splitting ratio of 95:5. The reflected light is used by the corneal topography measurement device. The choice of beam splitter not only ensures effective beam splitting but also guarantees high precision in corneal topography measurement. After passing through the beam splitter, the reflected light is precisely guided to the corneal topography measurement device for constructing a corneal topography map. This design allows wavefront aberration measurement and corneal topography measurement to be performed efficiently and accurately within the same instrument, greatly improving measurement efficiency and accuracy.

[0058] In one embodiment of this application, please refer to the following: Figure 3 and Figure 4 The second 4f system includes a second front achromatic lens 205 and a first rear achromatic lens 106, with a first beam splitter 203 and a second beam splitter 201 sequentially disposed between the second front achromatic lens 205 and the first rear achromatic lens 106.

[0059] In this embodiment, the second 4f system is also used to increase the peak power density of the emitted laser and reduce beam divergence. The combination of the second front achromatic lens 205 and the first rear achromatic lens 106 further reduces imaging distortion and ensures the stability of light propagation. In particular, the first beam splitter 203 and the second beam splitter 201 are cleverly positioned between the second front achromatic lens 205 and the second rear achromatic lens 202. This arrangement not only optimizes the optical path but also ensures the precise synchronization of wavefront aberration measurement and corneal topography measurement. The first beam splitter 203 plays a crucial role here, further subdividing the beam passing through the second 4f system. One part is guided to the wavefront aberrometer 304 for wavefront aberration measurement, while the other part continues to participate in the construction of the corneal topography map. This design not only improves the measurement accuracy but also greatly enhances the functionality of the instrument.

[0060] In this embodiment, depending on the size of the subject's cornea, the second 4f system can magnify (|β|>1) or reduce (|β|<1) the image formed by the wavefront aberration measuring device using different lens combinations, where β represents the magnification of the second 4f system. For species with smaller corneal diameters, the second 4f system uses |β|>1, such as a lens combination of f1 = 12.5cm and f2 = 20cm; for species with larger corneal diameters, the second 4f system uses |β|<1, such as a lens combination of f1 = 20cm and f2 = 12.5cm. This design allows the ocular parameter measuring instrument of this application to be applicable to subjects with different corneal sizes, further improving the instrument's applicability and flexibility. In practical implementation, the operator can flexibly adjust the lens combination in the second 4f system according to the subject's corneal size to achieve the best measurement results.

[0061] In one embodiment of this application, the eye parameter measuring instrument further includes a first aperture 204, see [link to relevant documentation]. Figure 3 The first aperture 204 is positioned between the first beam splitter 203 and the second beam splitter 201, or, please refer to [the relevant documentation]. Figure 1 and Figure 4 The first aperture 204 is disposed between the second front achromatic lens 205 and the first beam splitter 203.

[0062] In this embodiment, the aperture of the first aperture 204 is 3-7mm. The setting of the first aperture 204 can effectively control the diameter of the light beam and the incident angle of the light, prevent interference from stray light, and thus improve the accuracy of the measurement. In actual implementation, the operator can flexibly select the position of the first aperture 204 according to actual needs to achieve the best measurement effect.

[0063] In another embodiment of this application, please refer to [the relevant document / reference]. Figure 1 and Figure 2 The second beam splitter 201 is positioned between the first achromatic lens 106 and the Placido disc structure 401. This layout adjustment further optimizes the optical path design, making wavefront aberration measurement and corneal topography measurement smoother and less interfering with each other, thus improving measurement stability and accuracy. Simultaneously, this design facilitates independent debugging and optimization of the first 4f system and the corneal topography measurement device, improving instrument maintainability and performance. In practice, operators can flexibly select the position of the second beam splitter 201 according to actual measurement needs and scenarios to achieve optimal measurement results and instrument performance.

[0064] In another embodiment of this application, please refer to [the relevant document / reference]. Figure 1 and Figure 2 The second 4f system includes a second front achromatic lens 205 and a second rear achromatic lens 202. A second beam splitter 201 is disposed between the second rear achromatic lens 202 and the Placido disc structure 401; a first beam splitter 203 is disposed between the second front achromatic lens 205 and the second rear achromatic lens 202. This design also aims to optimize the optical path layout, ensuring the accuracy and synchronization of wavefront aberration measurement and corneal topography measurement. By placing the second beam splitter 201 between the second rear achromatic lens 202 and the Placido disc structure 401, the light beam can be guided into the corneal topography measurement device more effectively, while reducing interference with the wavefront aberration measurement device. The placement of the first beam splitter 203 between the second front achromatic lens 205 and the second rear achromatic lens 202 ensures that the light beam can be accurately split when passing through the second 4f system, and guided to the wavefront aberrometer 304 and the corneal topography measurement device respectively, further improving the measurement accuracy and instrument functionality. In practice, operators can flexibly adjust the component configuration of the second 4f system and the position of the spectroscopic element according to actual needs to achieve the best measurement results and instrument performance.

[0065] In another embodiment of this application, the eye parameter measuring instrument further includes a first aperture 204, which can be referred to in conjunction with the above. Figure 1 and Figure 4 The first aperture stop 204 is disposed between the second front achromatic lens 205 and the first beam splitter 203; or, please refer to Figure 2 The first aperture 204 is positioned between the first beam splitter 203 and the second rear achromatic lens 202.

[0066] In one embodiment of this application, please refer to the following: Figure 3 and Figure 4The third 4f system includes a third front achromatic lens 302 and a first rear achromatic lens 106, with a first beam splitter 203 and a second beam splitter 201 sequentially positioned between them. This design allows the third 4f system to not only effectively increase the peak power density of the emitted light and reduce beam divergence, but also further optimize the optical path layout through the ingenious arrangement of the first beam splitter 203 and the second beam splitter 201. The first beam splitter 203 plays a crucial role in re-splitting the beam, subdividing it to guide one part to the wavefront aberration measurement device and the other part to the corneal topography measurement device, ensuring accurate and synchronous measurement of wavefront aberration and corneal topography. Simultaneously, the combination of the third front achromatic lens 302 and the first rear achromatic lens 106 further reduces imaging distortion and improves the stability of light propagation, thereby enhancing the overall measurement accuracy and instrument performance.

[0067] In another embodiment of this application, please refer to [the relevant document / reference]. Figure 1 and Figure 2 The third 4f system includes a third front achromatic lens 302 and a second rear achromatic lens 202, a second beam splitter 201 disposed between the second rear achromatic lens 202 and the Placido disc structure 401; and a first beam splitter 203 disposed between the third front achromatic lens 302 and the second rear achromatic lens 202.

[0068] In this embodiment, depending on the size of the subject's cornea, the third 4f system can magnify (|β|>1) or reduce (|β|<1) the image of Placido using different lens combinations. For species with smaller corneal diameters, the third 4f system uses |β|>1, such as a lens combination of f1 = 12.5 cm and f2 = 20 cm; for species with larger corneal diameters, the third 4f system uses |β|<1, such as a lens combination of f1 = 20 cm and f2 = 12.5 cm.

[0069] In one embodiment of this application, please refer to the following: Figure 1 and Figure 4 The eye parameter measuring instrument also includes a second aperture 301, which is disposed between the third front achromatic lens 302 and the first beam splitter 203.

[0070] In this embodiment, the aperture of the second aperture 301 is 3-7 mm. The second aperture 301 is mainly used to block reflected light from the anterior surface of the cornea, and can be finely adjusted according to whether it can completely block reflected light from the anterior surface of the cornea; the second aperture 301 can also be used to control the incident angle of light. In practice, the operator can flexibly adjust the position and aperture size of the second aperture 301 according to the corneal characteristics of the examinee and the measurement requirements to achieve the best measurement results.

[0071] In this embodiment, the first beam splitter 203 is a long-pass dichroic mirror with a size of 32mm*60mm and a cutoff wavelength of 700nm.

[0072] In one embodiment of this application, please refer to the following: Figures 1 to 4 The eye parameter measuring instrument also includes a first bandpass filter 303, which is disposed between the wavefront aberrometer 304 and the third front achromatic lens 302.

[0073] In this embodiment, the first bandpass filter 303 is mainly used to allow light of a specific wavelength to pass through, in order to match the optical characteristics of the wavefront aberration meter 304. In this embodiment, the center wavelength of the first bandpass filter 303 is 800-850nm. This design can effectively filter out stray light and improve the accuracy of wavefront aberration measurement. At the same time, the setting of the first bandpass filter 303 also enhances the instrument's anti-interference ability against ambient light, ensuring stable measurement results under different lighting conditions.

[0074] In this embodiment, the wavefront aberration meter 304 is an SH wavefront aberration meter, which is used to receive light, analyze and utilize it to obtain wavefront aberration data of the subject's eye.

[0075] In one embodiment of this application, please refer to the following: Figures 1 to 4 The eye parameter measuring instrument also includes a second bandpass filter 206, which is disposed between the image acquisition element 207 and the second front achromatic lens 205.

[0076] In this embodiment, the second bandpass filter 206 is mainly used to allow light of a specific wavelength to pass through, in order to match the optical characteristics of the corneal topography measurement device. In this embodiment, the center wavelength of the second bandpass filter 206 is 500-550nm. This design can effectively filter out stray light and improve the accuracy of corneal topography measurement. At the same time, the setting of the second bandpass filter 206 also enhances the instrument's resistance to ambient light interference, further ensuring the stability and accuracy of the measurement.

[0077] In one embodiment of this application, the Placido disc structure 401 includes a lighting unit.

[0078] In this embodiment, the Placido disc structure 401 is a tool for evaluating ocular wavefront aberrations, designed based on a series of concentric rings. When these rings are projected onto the retina of the subject, the image of the rings is distorted due to ocular wavefront aberrations. By capturing and analyzing these distorted ring images through the image acquisition element 207, ocular wavefront aberration data can be calculated.

[0079] In one embodiment of this application, the Placido disc structure 401 can be designed with different numbers of rings to accommodate subjects with different corneal sizes. By adjusting the number of rings in the Placido disc structure 401, the coverage and resolution of the cornea being measured by the corneal topography measurement device can be changed. For subjects with larger corneas, a Placido disc structure 401 with more rings can be used to obtain more comprehensive corneal topography information; while for subjects with smaller corneas, a Placido disc structure 401 with fewer rings can be used to improve measurement accuracy and resolution.

[0080] For species with smaller corneal diameters, such as chickens or mice, due to their smaller eyes, a Placido ring with fewer rings is recommended, ideally 16 rings, to ensure clear projection of the rings onto the retina and accurate measurement results. For species with larger corneal diameters, such as humans or rabbits, due to their larger eyes, a Placido cone with more rings is recommended, ideally 32 or 36 rings, to provide more refined measurements and analysis.

[0081] Furthermore, the design of the Placido disc also takes into account the influence of the illumination unit. In this embodiment, a flexible LED, preferably green light with a wavelength of 530 nm, is selected as the illumination unit to ensure sufficient brightness and contrast when the circular image is projected onto the retina, thereby improving the accuracy and reliability of the measurement.

[0082] In this embodiment, the image acquisition element 207 is a CCD. The CCD acquires the image formed by the reflection of the cornea from the Placido disc structure 401, and analyzes and utilizes it to obtain the corneal topography data of the examinee.

[0083] The following testing process uses a human cornea as an example.

[0084] During the measurement process, the ambient light intensity in the measurement room must be moderate, with an ambient lighting requirement of 500-1000 Lux for the instrument's working area. Before conducting the test, based on the characteristics of the human cornea, in the wavefront aberration measurement device, the second 4f system should be selected with |β| < 1, such as a lens combination with f1 = 20cm and f2 = 12.5cm. In the corneal topography measurement device, a Placido cone with 36 rings should be used, and the third 4f system should be selected with |β| < 1, such as a lens combination with f1 = 20cm and f2 = 12.5cm. After selecting appropriate lens parameters and the Placido disc structure 401, the SLED emits an 840nm beam and the LED emits a 630nm beam. Both beams are transmitted into the coupling fiber 103 and then enter the first 4f system through the collimating lens 104. At this time, the examinee is instructed to open their eyes. When the light is clearly imaged on the examinee's retina and the focus is successful, the wavefront aberration image is captured by the wavefront aberrometer 304. At the same time, the illumination unit on the Placido disc structure 401 emits light, raising the examinee's upper eyelid to reduce the influence of eyelashes on corneal topography measurement. The CCD takes a picture and records it. Afterwards, the system analyzes and integrates the obtained data to obtain the examinee's corneal topography and the wavefront aberration of the examinee's eyes.

[0085] After one eye is measured, the other eye is measured. Once both eyes are measured, the results are displayed on the screen and recorded to create a file for the examinee for later retrieval.

[0086] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. An eye parameter measuring instrument, characterized in that, include: A wavefront pre-compensation device, comprising a compensation light source, a collimating lens, and a first 4f system arranged sequentially; A wavefront aberration measuring device, comprising a second 4f system, a first beam splitter, and a wavefront aberrator arranged sequentially. A corneal topography measurement device, comprising a Placido disc structure, a third 4f system, a second beam splitter, and an image acquisition element arranged sequentially; the Placido disc structure faces the eye of the subject. Wherein, the optical paths of the first 4f system and the third 4f system intersect at the second beam splitter; the optical paths of the second 4f system and the third 4f system intersect at the first beam splitter.

2. The eye parameter measuring instrument as described in claim 1, characterized in that, The compensation light source includes a first light source, a second light source, and a coupling optical fiber. The beam emitted by the first light source and the beam emitted by the second light source are combined into a single beam through the coupling optical fiber. The first light source is used to provide light for the wavefront aberration measurement device. The second light source is used to determine whether the eye position of the subject is correct.

3. The eye parameter measuring instrument as described in claim 1, characterized in that, The first 4f system includes a first front achromatic lens and a first rear achromatic lens arranged sequentially.

4. The eye parameter measuring instrument as described in claim 3, characterized in that, The second beam splitter is disposed between the first front achromatic lens and the first rear achromatic lens.

5. The eye parameter measuring instrument as described in claim 4, characterized in that, The second 4f system includes a second front achromatic lens and a first rear achromatic lens, with the first beam splitter and the second beam splitter sequentially disposed between the second front achromatic lens and the first rear achromatic lens.

6. The eye parameter measuring instrument as described in claim 5, characterized in that, The eye parameter measuring instrument further includes a first aperture, which is disposed between the first beam splitter and the second beam splitter, or the first aperture is disposed between the second front achromatic lens and the first beam splitter.

7. The eye parameter measuring instrument as described in claim 3, characterized in that, The second beam splitter is disposed between the first rear achromatic lens and the Placido disc structure.

8. The eye parameter measuring instrument as described in claim 7, characterized in that, The second 4f system includes a second front achromatic lens and a second rear achromatic lens, with the second beam splitter disposed between the second rear achromatic lens and the Placido disc structure; the first beam splitter is disposed between the second front achromatic lens and the second rear achromatic lens.

9. The eye parameter measuring instrument as described in claim 8, characterized in that, The eye parameter measuring instrument further includes a first aperture, which is disposed between the second front achromatic lens and the first beam splitter; or, the first aperture is disposed between the first beam splitter and the second rear achromatic lens.

10. The eye parameter measuring instrument as described in claim 6, characterized in that, The third 4f system includes a third front achromatic lens and a first rear achromatic lens, with the first beam splitter and the second beam splitter sequentially disposed between the third front achromatic lens and the first rear achromatic lens.

11. The eye parameter measuring instrument as described in claim 6, characterized in that, The third 4f system includes a third front achromatic lens and a second rear achromatic lens, with the second beam splitter disposed between the second rear achromatic lens and the Placido disc structure; the first beam splitter is disposed between the third front achromatic lens and the second rear achromatic lens.

12. The eye parameter measuring instrument as described in claim 10 or 11, characterized in that, The eye parameter measuring instrument also includes a second aperture, which is disposed between the third front achromatic lens and the first beam splitter.

13. The eye parameter measuring instrument as described in claim 12, characterized in that, The eye parameter measuring instrument also includes a first bandpass filter, which is disposed between the wavefront aberrometer and the third front achromatic lens.

14. The eye parameter measuring instrument as described in claim 13, characterized in that, The eye parameter measuring instrument also includes a second bandpass filter, which is disposed between the image acquisition element and the second front achromatic lens.

15. The eye parameter measuring instrument as described in claim 1, characterized in that, The Placido disc structure includes an illumination unit.

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