Crystal lens adjusting force measuring optometry unit

Abstract

The invention discloses an optometry unit for measuring the adjustment force of a crystalline lens, which is simple in structure and convenient to measure. Comprising a shell, a diopter measuring module and a fixation module, the fixation module forms a fixation light path for human eyes to watch, the fixation module comprises a sighting target plate and a fixation lens group which are arranged, the sighting target plate is provided with sighting targets for human eyes to observe, and the sighting target plate is movably arranged on the shell along the optical axis of the fixation light path; the shell is provided with a window which is over against the fixation optical path and is watched by human eyes; the optometry unit has a first measurement state and a second measurement state, in the first measurement state, the sighting mark is located in the fixation optical path, and a first distance is formed between the sighting mark and the window, so that a first image corresponding to the hyperopia diopter of the crystalline lens is collected; in the second measurement state, the sighting target on the sighting target plate is located in the fixation optical path and has a second distance with the window, so that a clear second image corresponding to the myopia diopter of the crystalline lens is collected; the first distance is greater than the second distance.

Description

[0001] This application is a divisional application of the invention patent with application number 2018102074968 and application date filed on March 14, 2018. Technical Field

[0002] The invention belongs to the field of ophthalmometers, and in particular relates to an ophthalmometer capable of measuring the accommodation power of a lens. Background Art

[0003] The lens is located in front of the vitreous body of the eye, and is connected to the ciliary body by the lens suspension ligament. It is biconvex and elastic. The lens is a biconvex transparent tissue, which is fixed by the suspension ligament and suspended behind the iris and in front of the vitreous body. In the lens, due to its own adjustment mechanism, it has hyperopia and myopia. The adjustment power of the lens is mainly reflected in its ciliary muscle. When the ciliary muscle is relaxed, the lens tends to be flat; when the ciliary muscle is tense, the lens tends to be round. In this way, the lens can selectively focus on near objects and far objects, thus corresponding to near vision and far vision. The lens is an important part of the eye's refractive system and the only refractive medium with adjustment ability. The formation of myopia and hyperopia is closely related to the adjustment ability of the lens. Therefore, it is necessary to measure the adjustment power of the lens.

[0004] For example, patent document US20150173600A1 discloses a system for evaluating the residual accommodation of hyperopic eyes, which receives a signal from a light sensor indicating the relative movement of the lens and the eyeball during the scanning movement through a controller, determines the relative zonular tension in the accommodation state and the de-accommodation state, and calculates the residual accommodation power in the patient's eye based on the comparison. However, it only measures the accommodation power of hyperopic glasses and the measurement algorithm is complicated. Summary of the invention

[0005] In view of the above problems, the object of the present invention is to provide a lens accommodation power measuring ophthalmometer, which has a simple structure and is convenient for measurement.

[0006] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0007] A refractometer capable of measuring the accommodative power of a lens comprises a housing, a diopter measuring module and a fixation module, wherein the diopter measuring module comprises a first light source for emitting a first light beam, and a first image collector for collecting a clear image formed by the first light beam after being reflected by the retina, and the fixation module forms a fixation optical path for human eyes to gaze at.

[0008] The fixation module comprises a sight mark plate and a fixation lens group, wherein the sight mark plate is provided with a sight mark for human eyes to observe, and the sight mark plate can be movably arranged on the housing along the optical axis of the fixation optical path; the housing is provided with a window for human eyes to gaze at, facing the fixation optical path;

[0009] The ophthalmometer has a first measurement state and a second measurement state. In the first measurement state, the sight mark on the sight mark plate is located in the fixation optical path and has a first distance from the window, so that the first image collector can collect a clear first image corresponding to the hyperopic diopter of the lens; in the second measurement state, the sight mark on the sight mark plate is located in the fixation optical path and has a second distance from the window, so that the first image collector can collect a clear second image corresponding to the myopic diopter of the lens; the first distance is greater than the second distance;

[0010] The ophthalmometer also includes a control module, which is used to obtain the distance vision diopter when the first image collector captures a clear first image and the near vision diopter when the second image is captured, and obtain the lens accommodation power according to the difference between the distance vision diopter and the near vision diopter.

[0011] In a preferred embodiment, the ophthalmometer further has a third measuring state, and in the third measuring state, the sight mark is not in the fixation optical path.

[0012] In a more preferred embodiment, the ophthalmometer also includes a corneal curvature measurement module, and the corneal curvature includes a second light source for emitting a second light beam and a second image collector for collecting a clear image formed after the second light beam is reflected by the retina. When the ophthalmometer is in the third measurement state, the second image collector collects the image of the retina to obtain the corneal curvature.

[0013] In some embodiments, the sight plate is detachably mounted on the housing, and the ophthalmometer further has a third measuring state. In the third measuring state, the sight plate is moved out of the housing; in the first and second measuring states, the sight plate is located inside the housing.

[0014] In some embodiments, the sight mark plate is rotatably disposed on the housing via a pivot, the pivot extends along the optical axis of the fixation optical path, and the ophthalmometer also has a third measuring state, in which the sight mark plate rotates to the side of the fixation optical path.

[0015] In some embodiments, the ophthalmometer also includes a corneal curvature measurement module, the corneal curvature is used to emit a second light source for emitting a second light beam, and a second image collector for collecting a clear image formed after the second light beam is reflected by the retina. When the ophthalmometer is in the third measurement state, the second image collector collects the image of the retina to obtain the corneal curvature.

[0016] In a preferred embodiment, the fixation module includes a fixation lens group consisting of a first lens group and a second lens group. In a preferred embodiment, the diopter measurement module is composed of a first light source, an aperture, a seventh lens group, a beam splitter, a second dichroic mirror, a third lens group, a first dichroic mirror, a fifth lens group, a sixth lens group, a first image collector and a first motor. In a preferred embodiment, the corneal curvature measurement module is composed of a second light source, a first dichroic mirror, a third lens group, a second dichroic mirror, a fourth lens group, a second image collector and a second motor.

[0017] In some embodiments, the ophthalmometer further comprises a driving mechanism for driving the sight mark plate to move.

[0018] In some embodiments, the driving mechanism includes a motor and a transmission assembly connected between the driving motor and the sight plate.

[0019] In some embodiments, the transmission assembly includes at least two synchronous wheels and a synchronous belt arranged on the at least two synchronous wheels, wherein one of the synchronous wheels is connected to the output shaft of the drive motor to drive the synchronous belt to move, and the sight plate is fixedly connected to the synchronous belt to move with the synchronous belt.

[0020] In some embodiments, the housing has a guide rail, and the sight plate is slidably disposed on the guide rail.

[0021] In some embodiments, the ophthalmometer also includes a control module, which is used to obtain the distance vision refractive power and the near vision refractive power of the first image collector when the clear first and second images are captured, and obtain the lens accommodation power according to the difference between the distance vision refractive power and the near vision refractive power.

[0022] In some embodiments, the refractive power measurement module also includes a first motor for driving the first image collector to move, and a position sensor for detecting the rotation angle of the output shaft of the first motor or the displacement of the first image collector. The control module is also electrically connected to the position sensor to obtain the image distance corresponding to when the first image collector captures a clear image, thereby obtaining the refractive power based on the image distance.

[0023] In a preferred embodiment, the first motor drives the first image collector to move via a lead screw, and a point on the lead screw is taken as a detection point. When the first image collector moves to the imaging position of the first light beam, the position of the detection point is recorded to obtain the image distance.

[0024] The present invention adopts the above technical solution, which has the following advantages compared with the prior art:

[0025] The lens measurement function is integrated into the existing ophthalmometer. The hyperopia and myopia refraction can be obtained by loading a movable sight mark on the fixation module. The lens accommodation power can be evaluated according to the difference between the two values ​​to obtain the lens accommodation power. The structure is simple and the measurement operation is convenient. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solution of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0027] Figure 1 is a schematic diagram of an optical system of an optometry instrument according to the present invention;

[0028] Figure 2 is a schematic diagram of the appearance of an optometry instrument according to the present invention;

[0029] Figure 3 is a schematic diagram of an annular aperture according to the present invention;

[0030] Figure 4a , 4b They are respectively a front view of a beam splitter according to the present invention and a projection schematic diagram along a diopter measurement optical path;

[0031] Figure 5 A schematic diagram of the connection between a sight plate and a driving assembly according to the present invention;

[0032] Figure 6 A schematic diagram of the sight plate being moved out of the housing;

[0033] Figure 7 This is a schematic diagram of the sight target plate being moved to the side of the fixation light path.

[0034] Among them, 1, the first lens group; 2, the second lens group; 3, the first dichroic mirror; 4, the second light source; 5, the third lens group; 6, the second dichroic mirror; 7, the fourth lens group; 8, the second image collector; 9, the first light source; 10, the aperture; 11, the seventh lens group; 12, the beam splitter; 13, the fifth lens group; 14, the sixth lens group; 15, the first image collector; 16, the sight mark;

[0035] 2. Shell; 21. Sight plate; 22. Window;

[0036] 20. Guide rail; 23. Slider; 24. Synchronous belt; 25. Synchronous wheel; 26. Driving motor. DETAILED DESCRIPTION

[0037] The preferred embodiments of the present invention are described in detail below in conjunction with the accompanying drawings so that the advantages and features of the present invention can be more easily understood by those skilled in the art. It should be noted that the description of these embodiments is used to help understand the present invention, but does not constitute a limitation of the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0038] The present embodiment provides an ophthalmometer that can measure the accommodative power of the lens, and the ophthalmometer also has the function of measuring diopter and corneal curvature of the traditional computer ophthalmometer. Below, the description of the accommodative power measurement function of the ophthalmometer is focused. The lens has far vision and near vision, far vision refers to the corresponding diopter when being able to clearly observe distant objects, and near vision refers to the corresponding diopter when being able to clearly observe objects entering and exiting; when the ciliary muscle of the lens functions well, the accommodative ability of the lens is strong, and the difference in diopter between hyperopia and myopia is large, and when the lens ages or degenerates due to age, disease or bad habits, its ciliary muscle function declines, and the accommodative ability of the lens decreases, so the difference in diopter between hyperopia and myopia is small; that is, the difference between the hyperopic diopter and the myopic diopter is in a certain positive proportional relationship with the accommodative power of the lens. The present invention is based on the positive proportional relationship between the difference between the hyperopia refraction and the myopia refraction and the lens accommodation power. It measures the hyperopia refraction and myopia refraction in hyperopia and myopia respectively, and evaluates the lens accommodation power according to the difference between the two, thereby achieving the purpose of measuring the lens accommodation power.

[0039] Reference Figure 1As shown, the optical system of the ophthalmometer includes a first lens group 1, a second lens group 2, a first dichroic mirror 3, a second light source, a third lens group 5, a second dichroic mirror 6, a fourth lens group 7, a second image collector 8, a second motor (not shown in the figure), a first light source 9, an aperture 10, a seventh lens group 11, a beam splitter 12, a fifth lens group 13, a sixth lens group 14, a first image collector 5, and a first motor (not shown in the figure). The fixation lens group formed by the first lens group 1 and the second lens group 2 is one of the components of the fixation module. The fixation module forms a fixation optical path for the human eye to gaze at. The fixation module adopts a telescopic system to control the observation direction and observation position of the human eye so that the exit pupil of the fixation module is consistent with the pupil of the human eye. In addition, the fixation module also includes a sight mark 16. The sight mark 16 is for the human eye to observe. The sight mark 16 can be moved along the optical axis of the fixation optical path (such as Figure 1 The optical axis of the fixation optical path is the axis line or optical axis of the fixation lens group. The second light source 4, the first dichroic mirror 3, the third lens group 5, the second dichroic mirror 6, the fourth lens group 7, the second image collector 8 and the second motor constitute a corneal curvature measurement module for measuring the corneal curvature. The first light source 9, the diaphragm 10, the seventh lens group 11, the beam splitter 12, the second dichroic mirror 6, the third lens group 5, the first dichroic mirror 3, the fifth lens group 13, the sixth lens group 14, the first image collector 5 and the first motor constitute a diopter measurement module for measuring the diopter of the retina. In other words, the optical system of the ophthalmometer capable of measuring the accommodative power of the lens is mainly composed of a fixation module, a diopter measurement module and a corneal curvature measurement module.

[0040] Reference Figure 2As shown, the fixation module, the diopter measurement module and the corneal curvature measurement module of the ophthalmometer are all arranged in a housing 2. A transparent window 22 for the human eye to gaze at is provided on the rear end of the housing 2. The sight mark 16 of the fixation module is specifically located on a sight mark plate 21 provided in the housing. When the sight mark plate 21 is in the fixation optical path, the sight mark 16 on the sight mark plate 21 can be observed through the window 22. The sight mark 16 can specifically be a crosshair. The directional words such as "front" and "back" mentioned in this article are defined with the human eye to be detected as a reference object, with the side closer to the human eye being the back, and vice versa being the front. The sight mark plate 21 can be movably arranged on the housing 2 along the optical axis of the fixation optical path, so that the distance between the sight mark 16 and the window 22, that is, the distance from the human eye, can be adjusted, so that the human eye can be hyperopic or myopic. The ophthalmometer has a first measurement state and a second measurement state. In the first measurement state, the sight mark 16 on the sight mark plate 21 is located in the fixation optical path and has a first distance with the window 22, so that the first image collector 15 can collect a clear first image corresponding to the hyperopic diopter of the lens; in the second measurement state, the sight mark 16 on the sight mark plate 21 is located in the fixation optical path and has a second distance with the window 22, so that the first image collector 15 can collect a clear second image corresponding to the myopic diopter of the lens; the first distance is greater than the second distance, that is, in the first measurement state, the sight mark 16 is located far away, the detected person's eye observes the sight mark 16 in the distance, and the lens is in a hyperopic state; in the second measurement state, the sight mark 16 is located near, the detected person's eye observes the sight mark 16 near, and the lens is in a myopic state.

[0041] In both the first measurement state and the second measurement state, the hyperopia diopter and the myopia diopter are measured by the diopter measurement module. The light source emission optical path of the diopter measurement module is as follows:

[0042] The first light source 9 emits a first light beam in the near-infrared band with a wavelength of 790 to 870 nm. The aperture 10, the seventh lens group 11, the beam splitter 12, the second dichroic mirror 6, the third lens group 5, and the first dichroic mirror 3 are sequentially arranged in the emission light path of the first light source 9. Figure 3As shown, the aperture 10 is an annular aperture 10, and the first light beam after passing through the annular aperture 10 is an annular near-infrared light beam. The second dichroic mirror 6 allows the second light beam (near-infrared light with a wavelength of 790 to 870 nm) to fully transmit and the first light beam (infrared light with a wavelength of 900 to 1000 nm) to fully reflect. The first dichroic mirror 3 allows the near-infrared light (near-infrared light with a wavelength of 790 to 870 nm) and infrared light (infrared light with a wavelength of 900 to 1000 nm) to fully reflect and allows the visible light (light with a wavelength of 400 to 700 nm) to fully transmit. The second light beam is transmitted from the beam splitter 12, the seventh lens group 11, and the second dichroic mirror 6 in sequence, converged by the third lens group 5, and then reflected by the first dichroic mirror 3 to the retina.

[0043] The image acquisition process of the refractive measurement module is as follows:

[0044] The first dichroic mirror 3, the third lens group 5, the second dichroic mirror 6, the beam splitter 12, the fifth lens group 13, the sixth lens group 14, and the first image collector 5 are sequentially arranged in the imaging optical path of the first light beam. Figure 4a , 4b As shown, the beam splitter 12 includes a reflective surface formed in the middle of the beam splitter 12, the reflective surface is elliptical, and the positive projection of the reflective surface along the imaging optical path of the first light beam is circular. The first light beam reflected by the retina is then reflected by the first dichroic mirror 3 to change the propagation direction, converged by the third lens group 5, transmitted by the second dichroic mirror 6, and then reflected by the reflective surface of the beam splitter 12 to change the propagation direction, and then converged by the fifth lens group 13 and imaged by the sixth lens group 14. The first motor drives the first image collector 5 to move for automatic focusing, so that the first image collector 5 moves to the imaging position for image acquisition, thereby acquiring a clear image, and the corresponding diopter value can be obtained according to the image distance at this time.

[0045] Reference Figure 5 As shown, in this embodiment, a guide rail 20 is fixedly provided on the housing 2, and a sight mark plate 21 is slidably arranged on the guide rail 20. Specifically, the sight mark plate 21 is slidably matched with the guide rail 20 through a slider 23 fixedly connected thereto. The guide rail 20 specifically extends along the front-back direction (i.e., the optical axis of the fixation optical path). The ophthalmometer also includes a driving mechanism for driving the sight mark plate 21 to move. The driving mechanism includes a driving motor 26 and a transmission assembly connected between the driving motor 26 and the sight mark plate 21, and the transmission assembly can be selected from a synchronous belt drive, a chain drive, etc. The transmission assembly selected in this embodiment specifically includes two synchronous wheels 25 and a synchronous belt 24 arranged on the two synchronous wheels 25, wherein one synchronous wheel 25 is connected to the output shaft of the driving motor 26 to drive the synchronous belt 24 to move, and the sight mark plate 21 is fixedly connected to the synchronous belt 24 to move forward and backward with the synchronous belt 24.

[0046] In a preferred embodiment, the sight plate 21 is detachably mounted on the housing 2, and the ophthalmometer further has a third measurement state. In the third measurement state, the sight plate 21 is moved out of the housing 2. Figure 6 As shown; in the first and second measuring states, the sight plate 21 is located inside the housing 2.

[0047] In another preferred embodiment, the sight mark plate 21 is rotatably disposed on the housing 2 via a pivot, the pivot extending along the optical axis of the fixation optical path, and the ophthalmometer further has a third measurement state. In the third measurement state, the sight mark plate 21 is rotated to the side of the fixation optical path, such as Figure 7 shown.

[0048] Specifically in this embodiment, when the ophthalmometer is in the third measurement state, the sight mark 16 is not in the fixation optical path, and the human eye cannot observe the sight mark 16 through the window 22 of the housing, and the corneal curvature measurement module measures the corneal curvature of the human eye. The light source emission optical path of the corneal curvature measurement module is as follows:

[0049] The second light source 4 emits a second light beam in the infrared band with a wavelength of 900 to 1000 nm. The second light source 4 includes eight LED projection modules, and the eight LED projection modules are arranged in a ring shape around the central axis of the third lens group 5 at equal intervals. Each LED projection module includes an LED lamp, a diffuser, a light-transmitting hole and a lens group of the second light source 4. The emitted second light beam is a ring-shaped infrared light. The first dichroic mirror 3 allows the visible light to be fully transmitted and the first light beam to be fully reflected. The first dichroic mirror 3 is arranged in the emission light path of the first light source 4 to reflect the second light beam onto the cornea of ​​the human eye, and the second lens group 2 is arranged between the first lens group 1 and the first dichroic mirror 3. The human eye looks at the second lens group 2 and the first lens group 1 through the first dichroic mirror 3 to keep the human eye in a relaxed state.

[0050] The image acquisition process of the keratometer module is as follows:

[0051] The first dichroic mirror 3, the third lens group 5, the second dichroic mirror 6, the fourth lens group 7, and the second image collector 8 are sequentially arranged in the imaging optical path of the second light beam. The second light beam reflected by the cornea is then reflected by the first dichroic mirror 3 to change the propagation direction, converged by the third lens group 5, and then reflected by the second dichroic mirror 6 to change the propagation direction again, and then converged by the fourth lens group 7 to form an image. The second motor drives the second image collector 8 to move for automatic focusing, so that the second image collector 8 moves to the imaging position for image acquisition. According to the annular image reflected by the cornea of ​​the subject collected by the second image collector 8, the curvature radius of the corresponding fitting circle is obtained, and then the curvature radius of the cornea of ​​the subject is calculated according to the corneal curvature algorithm.

[0052] The ophthalmometer also includes a control module, which is used to obtain the distance vision diopter and the near vision diopter of the first image collector when the first image collector collects the clear first and second images, and obtain the lens accommodation power according to the difference between the distance vision diopter and the near vision diopter. The diopter measurement module also includes a position sensor for detecting the rotation angle of the motor output shaft or the displacement of the first image collector, and the control module is also electrically connected to the position sensor to obtain the image distance corresponding to the first image collector when the first image collector collects the clear image, so as to obtain the diopter according to the image distance. During measurement, a point on the lead screw is taken as the detection point. When the first motor drives the first image collector 5 to move to the imaging position of the first light beam (the image quality collected at this position is the clearest) through the lead screw, the position of the detection point (or the rotation angle of the motor output shaft, the distance moved by the first image collector 5) is recorded, so as to obtain the image distance of the sixth lens group 14. The above-mentioned control module can be specifically a computer, and the ophthalmometer is a computer ophthalmometer, which can store, display and transmit the measurement results; the above-mentioned control module can also be a single-chip microcomputer or MCU control chip, etc.

[0053] The present invention integrates a lens measurement function on an existing ophthalmometer, obtains the diopter of hyperopia and myopia by loading a movable sight mark 16 on the fixation module, and evaluates the size of the lens accommodation power according to the difference between the two to obtain the lens accommodation power, and has a simple structure and convenient measurement operation; the fixation lens group of the fixation module of the present invention adopts a telescopic system composed of a first lens group and a second lens group, the exit pupil size of the fixation module matches the pupil of the human eye, and the field of view angle is only a few degrees. Compared with the fixation system of the existing ophthalmometer, it can effectively put the human eye in the correct observation position and in a relaxed state, and observe objects at the correct angle; the diopter measurement module and the corneal curvature measurement module respectively adopt a first motor and a second motor The machine drives the first image collector and the second image collector to focus automatically respectively, and there is no need to rely on the second person to adjust the focus. The examinee can complete the diopter adjustment force and corneal curvature measurement by himself. The optometry instrument of the present invention can be operated by a single person, and the measurement is convenient, which can effectively realize the miniaturization and portability of the optometry system; the present invention adopts a first dichroic mirror, which fully transmits the visible band (400-700nm) and fully reflects the infrared band (780-1000nm). Compared with the traditional optometry system, it can effectively prevent the second light source from stimulating the human eye and eliminate the influence of the human eye adjustment on the diopter measurement. At the same time, the high transmittance of the visible light part of the fixation module can make the human eye in a relaxed state for correct observation.

[0054] The above embodiment is only for illustrating the technical concept and features of the present invention, and is a preferred embodiment, and its purpose is to enable people familiar with the technology to understand the content of the present invention and implement it accordingly, and it cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A lens accommodation power measurement ophthalmometer, comprising a housing, a diopter measurement module and a fixation module, wherein the diopter measurement module comprises a first light source for emitting a first light beam, and a first image collector for collecting a clear image formed by the first light beam after being reflected by the retina, and the fixation module forms a fixation optical path for human eyes to gaze at, characterized in that: The fixation module comprises a sight mark plate and a fixation lens group, wherein the sight mark plate is provided with a sight mark for human eyes to observe, and the sight mark plate can be movably arranged on the housing along the optical axis of the fixation optical path; the housing is provided with a window for human eyes to gaze at, facing the fixation optical path; The ophthalmometer has a first measurement state and a second measurement state. In the first measurement state, the sight mark on the sight mark plate is located in the fixation optical path and has a first distance from the window, so that the first image collector can collect a clear first image corresponding to the hyperopic diopter of the lens; in the second measurement state, the sight mark on the sight mark plate is located in the fixation optical path and has a second distance from the window, so that the first image collector can collect a clear second image corresponding to the myopic diopter of the lens; the first distance is greater than the second distance; The ophthalmometer also includes a control module, which is used to obtain the distance vision diopter when the first image collector captures a clear first image and the near vision diopter when the second image is captured, and obtain the lens accommodation power according to the difference between the distance vision diopter and the near vision diopter.

2. The lens accommodation power measuring ophthalmometer according to claim 1, characterized in that: The ophthalmometer also has a third measuring state, in which the sight mark is not in the fixation optical path.

3. The lens accommodation power measuring ophthalmometer according to claim 2, characterized in that: The ophthalmometer also includes a corneal curvature measurement module, which includes a second light source for emitting a second light beam and a second image collector for collecting a clear image formed after the second light beam is reflected by the retina. When the ophthalmometer is in the third measurement state, the second image collector collects an image of the retina to obtain the corneal curvature.

4. The lens accommodation power measuring ophthalmometer according to claim 3, characterized in that: The sight plate is detachably disposed on the housing. When the optometre is in the third measuring state, the sight plate is moved out of the housing. When the optometre is in the first measuring state and the second measuring state, the sight plate is located in the housing.

5. The lens accommodation power measuring ophthalmometer according to claim 3, characterized in that: The sight mark plate is rotatably arranged on the housing via a pivot, and the pivot extends along the optical axis of the fixation optical path. When the ophthalmometer is in the third measuring state, the sight mark plate rotates to the side of the fixation optical path.

6. The lens accommodation power measuring ophthalmometer according to claim 3, characterized in that: The fixation module includes a fixation lens group consisting of a first lens group and a second lens group. The refractive power measurement module consists of a first light source, an aperture, a seventh lens group, a beam splitter, a second dichroic mirror, a third lens group, a first dichroic mirror, a fifth lens group, a sixth lens group, a first image collector and a first motor. The corneal curvature measurement module consists of a second light source, a first dichroic mirror, a third lens group, a second dichroic mirror, a fourth lens group, a second image collector and a second motor.

7. The lens accommodation power measuring ophthalmometer according to claim 1, characterized in that: The shell has a guide rail, and the sight mark plate is slidably arranged on the guide rail; the ophthalmometer also includes a driving mechanism for driving the sight mark plate to move, and the driving mechanism includes a driving motor and a transmission component connected between the driving motor and the sight mark plate.

8. The lens accommodation power measuring ophthalmometer according to claim 7, characterized in that: The transmission assembly includes at least two synchronous wheels and a synchronous belt arranged on the at least two synchronous wheels, wherein one of the synchronous wheels is connected to the output shaft of the driving motor to drive the synchronous belt to move, and the sight plate is fixedly connected to the synchronous belt to move with the synchronous belt.

9. The lens accommodation power measuring ophthalmometer according to claim 1, characterized in that: The refractive power measurement module also includes a first motor for driving the first image collector to move, and a position sensor for detecting the rotation angle of the output shaft of the first motor or the displacement of the first image collector. The control module is also electrically connected to the position sensor to obtain the image distance corresponding to when the first image collector captures a clear image, so as to obtain the refractive power based on the image distance.

10. The lens accommodation power measuring ophthalmometer according to claim 9, characterized in that: The first motor drives the first image collector to move via a lead screw, and a point on the lead screw is taken as a detection point. When the first image collector moves to the imaging position of the first light beam, the position of the detection point is recorded to obtain the image distance.

Images