ophthalmic devices

Abstract

To provide an ophthalmologic apparatus capable of determining whether or not there has been adjustment intervention by the eye to be tested during examination of weakest power.SOLUTION: An ophthalmologic apparatus includes: a subjective measurement optical system 44 measuring subjective refractive value of the eye E to be tested; a refract measurement system 43 measuring objective refractive properties of the eye E to be tested; and a control part 40 controlling the subjective measurement optical system 44 and the refract measurement system 43. The control part 40 measures objective refractive properties of the eye E to be tested by the refract measurement system 43, and performs objective monitoring to monitor objective measurement information (spherical equivalent degree) acquired by measurement when weakest power examination obtaining the weakest power that enables an examinee to read highest vision value or set arbitrary visual acuity value by the subjective measurement optical system 44.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to an ophthalmic device.

Background Art

[0002] Conventionally, when a cloud is applied to the test eye, the measurement switches to monocular measurement. For example, the examiner operates the controller 300 to remove the cloud from only the measurement eye while applying the cloud to both eyes of the subject, and sets it to the weakest power at which the highest visual acuity is obtained. Thereafter, an RG test, a cross cylinder test (cylinder axis test and cylinder power test), etc. are performed to prevent overcorrection, and an ophthalmic device for confirming the highest visual acuity value of one eye by a visual acuity test is known (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, at the weakest power test for obtaining the weakest power at which the highest visual acuity value or any set visual acuity value can be read in the subjective test, the adjustment function of focusing by the lens of the test eye is relaxed to obtain the weakest power. However, during the weakest power test, for example, if the test eye cannot fixate due to test fatigue or the spherical power is changed by the corrective lens, the adjustment function by the test eye may intervene. Therefore, in the weakest power test in which there is adjustment intervention by the test eye, if the test result is directly used as the subjective refractive value of the test eye, the test accuracy of the subjective refractive value will be reduced. On the other hand, the conventional technique described in Patent Document 1 has a problem that it is impossible to determine or confirm whether there is adjustment intervention by the test eye during the weakest power test.

[0005] This invention has been made in view of the above-mentioned problem, and aims to provide an ophthalmic device that can determine whether or not there was accommodation intervention by the eye being examined during the weakest power test. [Means for solving the problem]

[0006] To achieve the above objective, the ophthalmic apparatus of the present invention comprises a subjective measurement optical system for measuring the subjective refractive value of the eye under examination, an objective measurement optical system for measuring the objective refractive characteristics of the eye under examination, and a control unit for controlling the subjective measurement optical system and the objective measurement optical system. During a weakest power test, in which the subjective measurement optical system is used to determine the weakest power at which the highest visual acuity value or any set visual acuity value can be read, the control unit performs the measurement of the objective refractive characteristics of the eye under examination using the objective measurement optical system, and also performs objective monitoring to monitor the objective measurement information acquired by the measurement. This is performed at least from the start of the weakest power test until the end of the weakest power test. The data is obtained in real time, in a time-series format, simultaneously with the implementation of the lowest frequency test. Objective measurements are monitored, and a comparison is made to determine if there are any differences or fluctuations in the objective measurements. Based on the comparison results, if there is a difference or fluctuation exceeding a threshold in the objective measurements, it is determined that accommodation intervention occurred in the eye being examined during the weakest power test. The system includes an examiner controller that receives input operations from the examiner and outputs control signals to the control unit. The control unit takes the objective measurement information as information that represents the relationship between the objective measurement value and the power of the corrective lens of the eye being examined, using a two-dimensional coordinate graph. When performing the objective monitoring during the weakest power test, the control unit outputs a command to display the two-dimensional coordinate graph on the display unit of the examiner controller. [Effects of the Invention]

[0007] With the ophthalmic device of the present invention configured in this way, it is possible to determine whether or not accommodation intervention occurred by the eye being examined during the weakest power test. In addition, during the weakest power test, the examiner can easily determine whether or not the eye under test has made any accommodative intervention by looking at the two-dimensional coordinate graph displayed on the examiner's controller. [Brief explanation of the drawing]

[0008] [Figure 1] This is a perspective view showing the overall configuration of the ophthalmic device of Example 1. [Figure 2] This figure shows the detailed configuration of the left measuring optical system of the ophthalmic device in Example 1. [Figure 3] This flowchart shows the flow of the control processing procedure for the subjective examination of distance vision prescription (visual acuity test) using an objective monitor, which is performed in the control unit of Example 1. [Figure 4]This is a two-dimensional coordinate graph showing an example of the relationship characteristics of objective measurements (equivalent spherical frequencies) when the amount of cloud fog is changed in the cloud fog control performed by the control unit of Example 1. [Figure 5] This is an explanatory diagram of the RG test performed in the control unit of Example 1, showing examples of undercorrection, complete correction, and overcorrection. [Figure 6] This figure shows an example of a decimal visual acuity value target used as an ETDRS chart in the weakest power test performed by the control unit of Example 1. [Figure 7] This figure shows an example of a fractional visual acuity value target used as an ETDRS chart in the weakest power test performed by the control unit of Example 1. [Figure 8] This figure shows an example of a binocular balance test target icon used in the binocular balance test performed by the control unit of Example 1. [Figure 9] This figure shows a two-dimensional coordinate graph G of the monitor display example 1, which shows the relationship between the power of the corrective lens and the objective measurement value (equivalent spherical power) in the weakest power test. [Figure 10] This figure shows the relationship between objective measurements (equivalent spherical frequencies) and the time elapsed since the start of the subjective examination, as shown in the two-dimensional coordinate graph G' of the monitor display example 2. [Figure 11] This figure shows the relationship between the time from the start of the subjective examination and the objective measurement value (equivalent spherical power) for the additional lens, as shown in monitor display example 3, two-dimensional coordinate graph G''. [Figure 12] This figure shows an example of an objective monitoring screen with the two-dimensional coordinate graph G shown in Figure 9 displayed on the display unit of the examiner's controller. [Modes for carrying out the invention]

[0009] Hereinafter, embodiments for implementing the ophthalmic device of the present invention will be described based on Example 1 shown in the drawings.

[0010] (Example 1) The ophthalmic device 1 of Example 1 is a binocular open type device that can measure eye characteristics simultaneously for both eyes with the subject's left and right eyes open. In the ophthalmic device 1, it is also possible to measure eye characteristics one eye at a time by covering one eye or turning off the fixation target.

[0011] The configuration of the ophthalmic device 1 will be described with reference to FIG. 1. As shown in FIG. 1, the ophthalmic device 1 includes a support base 10, a measurement unit 20, an examiner's controller 30, and a control unit 40. Hereinafter, when viewed from the subject, the left - right direction is the X - direction, the up - down direction (vertical direction) is the Y - direction, and the direction orthogonal to the X - direction and the Y - direction (depth direction) is the Z - direction.

[0012] The support base 10 has a column 11 standing from the floor surface and an ophthalmic examination table 12 supported by the column 11. The ophthalmic examination table 12 is a table for placing devices and tools used for ophthalmic examination such as the examiner's controller 30 and for supporting the posture of the subject. The height position of the ophthalmic examination table 12 in the Y - direction may be fixed, or it may be supported by the column 11 so that the height position in the Y - direction can be adjusted. [[ID=]10]

[0013] [[ID=]11] [[ID=]12]The measurement unit 2 has an arm 21, a measurement head 22, and a forehead rest 23. One end of the arm 21 is supported by the tip of the column 11, and the other end extends from the column 11 along the Z - direction to the front side (subject side), and the measurement head 22 is attached to the tip. Thus, the measurement head 22 is suspended from the column 11 via the arm 21 above the ophthalmic examination table 12. Also, the arm 21 is movable in the Y - direction with respect to the column 11. Note that the arm 21 may also be movable in the X - direction and the Z - direction with respect to the column 11.

[0014] The measurement head 22 is a part that measures the eye characteristics of the subject eye E. The measurement head 22 has a drive unit 22a and a pair of left and right measurement units 22L and 22R provided below the drive unit 22a. Here, the left measurement unit 22L and the right measurement unit 22R are paired to individually correspond to the left and right eyes of the subject. The left measurement unit 22L incorporates a left measurement optical system 25L that measures the eye characteristics of the left subject eye E (left subject eye) on the left side of the subject. The right measurement unit 22R incorporates a right measurement optical system 25R that measures the eye characteristics of the right subject eye E (right subject eye) on the right side of the subject. The measurement results by the measurement head 22 are input to the control unit 40.

[0015] The drive unit 22a is a mechanism that individually drives the left measurement unit 22L and the right measurement unit 22R for horizontal (X-direction) movement drive, vertical (Y-direction) movement drive, X-direction rotation drive, and Y-direction rotation drive.

[0016] Also, the ophthalmic device 1 is an objective measurement device with a subjective function that integrally includes a subjective measurement optical system, an objective measurement optical system, a phoropter, and a vision chart, and can objectively and subjectively measure the eye characteristics of the subject eye E. That is, the examiner can perform arbitrary objective examinations and subjective examinations using the ophthalmic device 1. In the objective examination, the subject eye E is irradiated with light, and information (eye characteristics) regarding the subject eye E is measured based on the detection result of the returned light.

[0017] Here, the objective examination includes a measurement for acquiring the eye characteristics of the subject eye E and a photographing for acquiring an image of the subject eye E. The objective examination includes refractive power measurement (refractometry), corneal shape measurement (keratometry), intraocular pressure measurement, fundus photography, tomographic imaging (OCT imaging) using optical coherence tomography (hereinafter, OCT: an abbreviation for "Optical Coherence Tomography"), measurement using OCT, etc. In the subjective examination, a visual target or the like is presented to the subject, and information (eye characteristics) regarding the subject eye E is measured based on the response of the subject to the presented visual target or the like. The subjective examination includes subjective refractive measurements such as distance vision examination, intermediate vision examination, near vision examination, contrast examination, glare examination, etc., and visual field examination, etc.

[0018] Therefore, the left measuring optical system 25L and the right measuring optical system 25R built into the measuring head 22 include, as shown in Figure 2, an observation system 41 for observing the anterior segment of the eye E under examination, a target projection system 42 for presenting a target to the eye E under examination, a refract measurement system 43 and a kerat measurement system 47 (left eye objective measurement optical system, right eye objective measurement optical system) for measuring the ocular characteristics of the eye E under examination. The detailed configuration of the left measuring optical system 25L and the right measuring optical system 25R will be described later.

[0019] The forehead rest 23 is provided on the measurement unit 20 and is positioned between the left measurement unit 22L and the right measurement unit 22R. The forehead rest 23 supports the subject's face by making contact with a part of the subject's face (forehead) during the measurement of eye characteristics. That is, the subject, facing the eye examination table 12, presses their forehead against the forehead rest 23 to stabilize their face and prevent movement in its orientation or position. The position of the forehead rest 23 is adjusted by moving the arm 21 in the Y direction relative to the support column 11.

[0020] The examiner controller 30 is an information processing device that receives input operations from the examiner and outputs control signals to the control unit 40. The examiner controller 30 is, for example, a tablet terminal or a smartphone, and is separate from the measurement unit 20 and portable by the examiner. The examiner controller 30 may also be a notebook computer or a desktop computer, or it may be a dedicated controller for the ophthalmic device 1. The examiner controller 30 exchanges information with the control unit 40 via wireless communication or network communication.

[0021] Furthermore, as shown in Figure 1, the examiner controller 30 includes a display unit 31, an operator-side control unit (not shown), and input buttons (not shown). The display unit 31 is a touch panel display provided on the surface of the examiner controller 30, and the input buttons are set via the screen display. The operator-side control unit consists of a microcomputer built into the examiner controller 30. The operator-side control unit controls the image displayed on the display unit 31 based on the measurement results and detection results transmitted from the control unit 40. The operator-side control unit also outputs control signals to the control unit 40 in response to operations on the input buttons.

[0022] The control unit 40 is an information processing device located below the eye examination table 12. Based on control signals transmitted from the examiner controller 30, the control unit 40 comprehensively controls each part of the measurement unit 20, including the left measurement optical system 25L and the right measurement optical system 25R, which have objective measurement optical systems (refract measurement system 43, kerat measurement system 47) and a target projection system 42. The control unit 40 also transmits the measurement results of the ocular characteristics of the eye E measured by the measurement head 22 to the examiner controller 30.

[0023] Next, the detailed configurations of the left measuring optical system 25L and the right measuring optical system 25R will be described with reference to Figure 2. Since the left measuring optical system 25L and the right measuring optical system 25R have the same configuration, the description of the right measuring optical system 25R will be omitted below, and only the left measuring optical system 25L will be described.

[0024] As shown in Figure 2, the left measurement optical system 25L includes an observation system 41, a target projection system 42, a subjective measurement optical system 44, a first alignment system 45, a second alignment system 46, and two examples of objective measurement optical systems: a refract measurement system 43 and a kerat measurement system 47. Here, the subjective measurement optical system 44, the refract measurement system 43, and the kerat measurement system 47 are all measurement optical systems that measure the ocular characteristics of the eye E under examination.

[0025] The observation system 41 includes an objective lens 41a, a first dichroic filter 41b, a first half mirror 41c, a first relay lens 41d, a second dichroic filter 41e, an imaging lens 41f, and an image sensor (CCD, etc.) 41g.

[0026] In the observation system 41, the light beam reflected from the eye E (anterior segment) is imaged onto the image sensor 41g by the imaging lens 41f after passing through the objective lens 41a. As a result, an anterior segment image E' is formed on the image sensor 41g, onto which the keratinizing light beam, the light beam from the first alignment light source 45a, and the light beam from the second alignment light source 46a (bright spot image Br) are projected. The image sensor 41g captures the anterior segment image E' and acquires the image signal of the anterior segment image E'. The control unit 40 displays the anterior segment image E', etc., based on the image signal output from the image sensor 41g on the display unit 31 of the examiner controller 30.

[0027] A keratometry system 47 is provided in front of the objective lens 41a. The keratometry system 47 is an example of an objective measurement optical system and measures the corneal shape (radius of curvature) of the eye E under examination. The keratometry system 47 includes a keratometry plate 47a and a keratometry ring light source 47b. The keratometry plate 47a is plate-shaped with a slit concentric with respect to the optical axis of the observation system 41 and is provided near the objective lens 41a. The keratometry ring light source 47b is provided in accordance with the slit in the keratometry plate 47a.

[0028] In the keratometry measurement system 47, the light beam from the lit keratometry light source 47b passes through the slit in the keratometry plate 47a, projecting a keratometry light beam (a ring-shaped target for measuring corneal curvature) onto the eye E (cornea Ec) for measuring corneal shape. The keratometry light beam is reflected by the cornea Ec of the eye E and is imaged onto the image sensor 41g by the observation system 41. As a result, the image sensor 41g detects (receives) an image of the ring-shaped keratometry light beam. The control unit 40 displays the image of the keratometry light beam detected by the image sensor 41g on the display unit 31. Furthermore, the control unit 40 measures the corneal shape (radius of curvature) of the eye E using a well-known method based on the image signal detected by the image sensor 41g.

[0029] A first alignment system 45 is provided behind the keratometry system 47 (keratometry plate 47a). The first alignment system 45 aligns the optical system with respect to the eye E under examination in the direction along the optical axis of the observation system 41 (front-to-back direction, Z direction). The first alignment system 45 has a pair of first alignment light sources 45a and a pair of first projection lenses 45b.

[0030] In the first alignment system 45, the light beams from each first alignment light source 45a are made into parallel light beams by each first projection lens 45b, and the parallel light beams are projected onto the cornea Ec of the eye E under examination through alignment holes provided in the keratin plate 47a.

[0031] The control unit 40 or the examiner performs alignment in the direction along the optical axis (front-to-back direction) of the observation system 41 by moving the left measuring unit 22L (or right measuring unit 22R) in the front-to-back direction based on the bright spot (bright spot image Br) projected onto the cornea Ec. When performing alignment in the front-to-back direction, the control unit 40 or the examiner adjusts the position of the left measuring unit 22L (or right measuring unit 22R) so that the ratio of the distance between the two point images from the first alignment light source 45a on the image sensor 41g to the diameter of the keratling image falls within a predetermined range.

[0032] Furthermore, the observation system 41 is provided with a second alignment system (parallel optical system) 46. The second alignment system 46 aligns the optical system with respect to the eye E under examination in directions perpendicular to the optical axis of the observation system 41 (up and down and left and right directions; Y direction and X direction). The second alignment system 46 has a second alignment light source 46a and a second projection lens 46b. The second alignment system 46 also shares a first half mirror 41c, a first dichroic filter 41b, and an objective lens 41a with the observation system 41.

[0033] In the second alignment system 46, the light beam from the second alignment light source (point light source) 46a is converted into a parallel light beam via the objective lens 41a and projected onto the cornea Ec of the eye E under examination. The parallel light beam projected from the second alignment system 46 onto the cornea Ec of the eye E under examination forms a bright spot of alignment light approximately midway between the corneal apex and the center of curvature of the corneal Ec.

[0034] The control unit 40 or the examiner moves the left measuring unit 22L (or the right measuring unit 22R) in the vertical or horizontal direction based on the bright spot (bright spot image Br) projected onto the cornea Ec, thereby aligning the observation system 41 in a direction perpendicular to the optical axis (vertical direction, horizontal direction).

[0035] The target projection system 42 projects a target (fixation target) onto the fundus Ef of the eye E to cause fixation and fogging of the eye E under examination. The subjective measurement optical system 44 also projects a target onto the eye E under examination during subjective examination. In the ophthalmic device 1, the target projection system 42 and the subjective measurement optical system 44 share the same optical elements that make up the optical system.

[0036] The target projection system 42 (subjective measurement optical system 44) includes a display 42a, a second half mirror 42b, a second relay lens 42c, a first reflective mirror 42d, a first focusing lens 42e, a third relay lens 42f, a first field lens 42g, a variable cross cylinder lens (VCC) 42h, a second reflective mirror 42i, and a third dichroic filter 42j. The target projection system 42 (subjective measurement optical system 44) also shares the first dichroic filter 41b and the objective lens 41a with the observation system 41. Furthermore, the target projection system 42 (subjective measurement optical system 44) has at least two glare light sources 42k that irradiate the eye E under examination with glare light at positions surrounding the optical axis via an optical path separate from the optical path leading to the display 42a, etc., for subjective examination.

[0037] The display 42a displays fixation targets and point targets as visual targets to fix the gaze when performing objective examinations or when applying fogging to the eye E under examination, or displays subjective test targets for subjectively examining the ocular characteristics of the eye E under examination (visual acuity, distance power, near power, etc.). The display 42a can use an organic EL (electroluminescent) or liquid crystal display (LCD) and is controlled by the control unit 40 to display any image. The display 42a is positioned in the optical path of the target projection system 42 (subjective measurement optical system 44) at a position conjugate to the fundus Ef of the eye E under examination.

[0038] The first focusing lens 42e is driven to move forward and backward along the optical axis by a drive motor (not shown) controlled by the control unit 40. The control unit 40 can shift the refractive index to the negative side by moving the first focusing lens 42e toward the eye under examination E. The control unit 40 can also shift the refractive index to the positive side (far viewing direction) by moving the first focusing lens 42e away from the eye under examination E. Therefore, the control unit 40 changes the presentation position of the target displayed on the display 42a by driving the first focusing lens 42e forward and backward, and changes the examination distance from the target presentation position to the eye under examination E.

[0039] Furthermore, the target projection system 42 (subjective measurement optical system 44) is equipped with a pinhole plate 42p at a position in the optical path that is approximately conjugate to the pupil of the eye E being examined (between the first field lens 42g and VCC 42h in the example shown in Figure 2). The pinhole plate 42p is formed from a plate member with a through hole. The pinhole plate 42p is controlled by the control unit 40, which enables insertion into and removal from the optical path of the target projection system 42 (subjective measurement optical system 44). When the pinhole plate 42p is inserted into the optical path, the through hole is positioned on the optical axis. In addition, the pinhole plate 42p is inserted into the optical path during subjective examination, enabling a pinhole test to determine whether or not the eye E being examined can be corrected with glasses. Note that the pinhole plate 42p only needs to be positioned in the optical path that is approximately conjugate to the pupil of the eye E being examined, and is not limited to the configuration shown in Figure 2.

[0040] The visual targets displayed on the display 42a during subjective examinations are not particularly limited as long as they are used in optometry, and examples include Landolt rings, Snellen targets, and E charts. The visual targets may be still images or moving images. Since the ophthalmic device 1 is equipped with a display 42a made of an LCD or the like, it can display visual targets of the desired shape, form, and contrast at a predetermined examination distance, enabling multifaceted and thorough optometry. Furthermore, the ophthalmic device 1 is equipped with two displays 42a, one corresponding to the left and one to be examined (E). Therefore, the ophthalmic device 1 can display visual targets that produce parallax in accordance with a predetermined examination distance (presentation position), and stereopsis examinations can be performed easily and precisely with a natural orientation of the visual axis.

[0041] Furthermore, in the target projection system 42, when fogging is applied to the eye E under examination, a fixation target (visual target) is presented to the eye E under predetermined presentation conditions. The "presentation conditions" are indicated, for example, by the presentation position of the fixation target. In Example 1, for simplicity, the presentation conditions are indicated by the diopter equivalent value based on the presentation position of the fixation target.

[0042] The refract measurement system 43 is an example of an objective measurement optical system and measures the refractive power of the eye E under examination. In Example 1, the refract measurement system 43 has the function of projecting a predetermined measurement pattern onto the fundus Ef of the eye E under examination and the function of detecting the image of the measurement pattern projected onto the fundus Ef. Specifically, the refract measurement system 43 includes a ring-shaped light beam projection system 43A that projects a ring-shaped measurement pattern onto the fundus Ef of the eye E under examination, and a ring-shaped light beam receiving system 43B that detects (receives) the reflected light of the ring-shaped measurement pattern from the fundus Ef.

[0043] The ring-shaped light beam projection system 43A includes a reflector light source unit 43a, a fourth relay lens 43b, a pupil ring diaphragm 43c, a second field lens 43d, a perforated prism 43e, and a rotary prism 43f. The ring-shaped light beam projection system 43A also shares a third dichroic filter 42j with the target projection system 42 (subjective measurement optical system 44), and shares a first dichroic filter 41b and an objective lens 41a with the observation system 41. The reflector light source unit 43a includes, for example, a reflector measurement light source 43g using an LED, a collimator lens 43h, a conical prism 43i, and a ring pattern forming plate 43j. The reflector light source unit 43a is controlled by the control unit 40 and moves integrally along the optical axis of the reflector measurement system 43.

[0044] The ring-shaped light beam receiving system 43B includes the hole 43p of the perforated prism 43e, the third field lens 43q, the third reflecting mirror 43r, the fifth relay lens 43s, the second focusing lens 43t, and the fourth reflecting mirror 43u. The ring-shaped light beam receiving system 43B shares the objective lens 41a, the first dichroic filter 41b, the second dichroic filter 41e, the imaging lens 41f, and the image sensor 41g with the observation system 41. Furthermore, the ring-shaped light beam receiving system 43B shares the third dichroic filter 42j with the target projection system 42 (self-awareness measurement optical system 44), and shares the rotary prism 43f and the perforated prism 43e with the ring-shaped light beam projection system 43A.

[0045] When measuring the refractive power of the eye E under examination using the refract measurement system 43, the control unit 40 first turns on the refract measurement light source 43g. Then, the control unit 40 moves the refract light source unit 43a of the ring-shaped light beam projection system 43A and the second focusing lens 43t of the ring-shaped light beam receiving system 43B in the optical axis direction. In the ring-shaped light beam projection system 43A, the refract light source unit 43a emits a ring-shaped measurement pattern, which is then propagated through the fourth relay lens 43b, the pupil ring diaphragm 43c, and the second field lens 43d to the perforated prism 43e, where it is reflected by its reflective surface 43v and guided through the rotary prism 43f to the third dichroic filter 42j. The ring-shaped light beam projection system 43A projects a ring-shaped measurement pattern onto the fundus Ef of the eye E under examination by guiding its measurement pattern through the third dichroic filter 42j and the first dichroic filter 41b to the objective lens 41a.

[0046] The ring-shaped light beam receiving system 43B focuses the ring-shaped measurement pattern formed on the fundus Ef with the objective lens 41a, and directs it through the first dichroic filter 41b, the third dichroic filter 42j, and the rotary prism 43f to the hole 43p of the perforated prism 43e. Subsequently, the ring-shaped light beam receiving system 43B causes the measurement pattern to pass through the third field lens 43q, the third reflective mirror 43r, the fifth relay lens 43s, the second focusing lens 43t, the fourth reflective mirror 43u, the second dichroic filter 41e, and the imaging lens 41f, thereby forming an image on the image sensor 41g. As a result, the image sensor 41g detects the image of the ring-shaped measurement pattern, and the control unit 40 displays the image of the measurement pattern detected by the image sensor 41g on the display unit 31. The control unit 40 then measures the spherical power, cylindrical power, and axial angle as refractive power of the eye based on the image signal from the image sensor 41g using a well-known method.

[0047] The configurations of the refractometer 43, the first alignment system 45, the second alignment system 46, and the keratometer 47, as well as the subjective examination and the measurement principles of the refractive power (refractometer) and corneal shape (keratometer) of the eye being examined, are publicly known, so a detailed explanation will be omitted.

[0048] Next, the control processing procedure for the subjective examination of distance vision prescription (visual acuity test) performed by the control unit 40 in conjunction with an objective monitor will be explained based on the flowchart shown in Figure 3. The subjective examination begins when the subject is seated in front of the ophthalmic device 1 and the gaze of the subject eye E is fixed on the fixation target.

[0049] Step S1 is the process of focusing the eye E under examination at the fog start position, and is performed, for example, in the following procedure. Specifically, the control unit 40 calculates the provisional spherical power S and cylindrical power C of the eye under examination E based on the ring image acquired using the refractive power measurement system 43. Then, based on the calculation results of the provisional spherical power S and cylindrical power C, the control unit 40 controls the second focusing lens 43t to move the focal position of the pattern light to a position corresponding to the equivalent spherical power (S + C / 2) (a position corresponding to the provisional far point: fog start position). Note that "fog amount" is the amount (intensity) of fog added to the eye under examination E and is expressed as the presentation position (presentation distance) of the fixation target.

[0050] In step S2, following the preliminary measurements in step S1, fogging control is performed, and the process proceeds to the next step, S3. Here, "fogging control" refers to a control method that monitors the objective measurement values ​​(or equivalent spherical power) as the amount of fogging is gradually increased to the positive side, in order to confirm whether the lens of the eye E being examined is relaxed prior to the subjective examination. For example, as shown in Figure 4, the amount of fogging is gradually increased from 0.0D to a predetermined amount in the positive side (e.g., +0.25D), and objective measurement values ​​are acquired at each timing of the gradual increase. Then, a characteristic line is graphed connecting, for example, 7 objective measurement values ​​to the amount of fogging (diopter equivalent). At this time, for subjects 2 and 3, if a change in the objective measurement values ​​is observed, it is determined that there is a possibility that the lens of the eye E being examined is tense. For subject 1, if no change in the objective measurement values ​​is observed, it is determined that the lens of the eye E being examined is relaxed. If there is a possibility that the lens is tense, the amount of fogging is increased until it is determined that the lens is relaxed. You may decide on a limit to the amount of increase and terminate the process even if there is a possibility that the lens is straining. In that case, an alert will be issued indicating that there is a possibility that the lens is straining. When increasing the amount of haze, the position of the fixation target should be moved towards the distance (positive side), and when decreasing the amount of haze, the position of the fixation target should be moved towards the near (negative side). Also, the "diopter equivalent value (=D value)" is a unit of lens refractive power that is calculated as the reciprocal of the distance at which the image is in focus, expressed in meters.

[0051] In step S3, following the implementation of fogging control in step S2, the process proceeds to "main measurement." "Main measurement" is the process of measuring the desired predetermined ocular characteristics. For example, when performing objective refraction measurement (refractive measurement), the following procedure is followed. Specifically, the control unit 40 projects a ring-shaped measurement pattern onto the fundus Ef of the eye E under fogging using the ring-shaped light beam projection system 43A. The control unit 40 then detects (receives) the reflected light of the ring-shaped measurement pattern from the fundus Ef using the ring-shaped light beam receiving system 43B, and measures the spherical power, cylindrical power, and cylindrical axis angle as refractive power using a well-known method based on the image signal from the image sensor 41g. Steps S1 to S3 are objective examinations, while steps S4 onwards are subjective examinations such as the RG test ("Red-Green Test") and the weakest power test. Subjective examinations begin after confirming that the lens of the eye E being examined is in a relaxed state, and are performed one eye at a time until the binocular balance test.

[0052] In step S4, following the determination that the main measurement in step S3 is complete, or the change of the eye E under examination in step S12, the start setting for the subjective examination is performed for one eye, either the right or left eye, and the process proceeds to step S5. Here, "start setting for the subjective examination" means setting a value obtained by adding, for example, +0.50D to the spherical power from the equivalent spherical power (for example, -1.0D) obtained in the main measurement, for fogging, to the phoropter built into the ophthalmic device 1.

[0053] In Step S5, following the initial setup of the subjective examination in Step S4, an RG test using the RG Chart 50 is performed, and the patient proceeds to Step S6. Here, the "RG Chart 50" is, as shown in Figure 5, a chart with red icons, for example, numbers of different sizes and circles of different sizes, and green icons, which use the same targets as the red icons, arranged side by side. The "RG test" is a test that uses the RG Chart 50 to check whether the correction power is overcorrected or undercorrected, using a characteristic of light called chromatic aberration. Due to the characteristics of the transparent media of the eye, the shorter the wavelength of light, the greater the power at the refractive surface, so green wavelength light is imaged at a position shifted towards the incident side compared to red wavelength light. Therefore, in the undercorrected state of the eye E shown at the top of Figure 5, the targets are imaged in front of the retina, but the red wavelength light is imaged further back, so the red targets are more clearly visible. In the fully corrected state shown in the center of Figure 5, the green and red targets are seen at roughly equal levels. In the case of overcorrection shown at the bottom of Figure 5, the green target is actually easier to see. Therefore, in RG testing, adjustments are made by adding or changing corrective lenses until the green and red targets on the RG chart 50 appear equally clear.

[0054] In Step S6, following the RG test in Step S5, adjustments are made to the cylindrical axis, cylindrical power, and spherical power, and the process proceeds to Step S7. Here, the "adjustment of cylindrical axis, cylindrical power, and spherical power" is performed by selecting the icon for the cross-cylinder test target (not shown in the diagram) from the chart page and rotating the Variable Cross-Cylinder Lens 42h so that the test target is clearly visible. Therefore, the "adjustment of cylindrical axis, cylindrical power, and spherical power" is also called the cross-cylinder test. For example, the icon for the cross-cylinder test target may be a circular arrangement of numerous dots.

[0055] In step S7, following the adjustment of the cylindrical axis, cylindrical power, and spherical power in step S6, or the change of the internal lens in step S9, the LogMAR visual acuity value is measured using the ETDRS chart, and the patient proceeds to step S8. Here, ETDRS stands for "Early Treatment Diabetic Retinopathy Study," and LogMAR stands for "Logarithmic Minimum Angle of Resolution." The ETDRS chart used includes the decimal visual acuity value target 51 shown in Figure 6 and the fractional visual acuity value target 52 shown in Figure 7. "Measurement of LogMAR visual acuity value" refers to measuring visual acuity using an ETDRS chart in which targets are arranged in a geometric progression, as shown in Figures 6 and 7. Arranging the targets in a geometric progression makes the logarithms equally spaced, which is convenient for statistical processing such as mean and standard deviation. In Japan, the decimal visual acuity value target 51 shown in Figure 6 is generally used, while overseas, the fractional visual acuity value target 52 shown in Figure 7 is generally used. The above target is just an example; any target suitable for visual acuity measurement can be displayed to measure visual acuity values. The LogMAR visual acuity value measured in step S7 is considered the highest visual acuity value in that visual acuity test.

[0056] In step S8, following the measurement of LogMAR visual acuity values ​​in step S7, it is determined whether the visual acuity values ​​have converged to the target value. If YES, proceed to step S10. If NO, proceed to step S9. Here, "target value" includes not only the target visual acuity value in the weakest power test that yields the highest visual acuity value (= highest visual acuity value), but also the target visual acuity value in the weakest power test that allows the reader to read any set visual acuity value target (= arbitrary visual acuity value).

[0057] In step S9, following the determination that the visual acuity value in step S8 has not converged to the target value, the internal lens of the ophthalmic device 1 is changed, and the process returns to step S7. This is repeated until the visual acuity value determined by subjective testing converges to the target value. Here, changing the internal lens of the ophthalmic device 1 means, for example, automatically or manually switching to a corrective lens that changes the spherical power, for example, by +0.25D increments.

[0058] In step S10, following the determination that the visual acuity values ​​in step S8 have converged to the target value, the weakest power at which the highest visual acuity value or any desired visual acuity value can be read is determined. This weakest power is then used as the subjective refractive value obtained through subjective examination with ophthalmic device 1, and the process proceeds to step S11.

[0059] In step S11, following the setting of subjective refractive values ​​in step S10, it is determined whether the examination of both eyes has been completed. If YES, proceed to step S13; if NO, proceed to step S12.

[0060] In step S12, following the determination in step S11 that the examination of both eyes is not yet complete, the eye under examination E is changed, and the process returns to step S4. For example, if the examination of the right eye of eye under examination E has already been completed, it is changed to the left eye, which has not yet been examined. When eye under examination E is changed, the same RG test and weakest power test as the examination of the eye that has already been examined are performed until it is determined that the examination of both eyes is complete.

[0061] In step S13, following the determination that the binocular examination in step S11 is complete, a binocular balance test is performed to adjust the balance of visual acuity between the left and right eyes, and the process proceeds to step S14. In this binocular balance test, the binocular balance test target icon 53 is selected from the chart page, for example, as shown in Figure 8, which consists of multiple letters of different sizes and multiple Landolt rings divided into upper and lower rows. The subject then compares how they see when they look at the upper row with their right eye and the lower row with their left eye (the device's internal targets can present targets corresponding to the left and right eyes), and asks the subject which eye they see better. The test is then ended when the upper and lower rows appear the same, or just before the eye that sees better reverses. If the binocular balance is judged to be ambiguous when the binocular balance test is performed with both eyes of the subject eye E looking at the targets simultaneously, the cause of the ambiguity is confirmed by either occluding one eye of the subject eye E or by leaving both eyes open. When performing a monocular examination with one eye of the eye being examined E covered, or a monocular examination with both eyes open, for example, select the binocular balance test target icon using two deflected colors.

[0062] In step S14, following the binocular balance test in step S13, once the binocular balance test is completed, the subjective refractive values ​​and best visual acuity values ​​of both eyes, which are the measurement results from the tests performed in the above process, are recorded, and the process proceeds to the end.

[0063] In step S15, refract measurement is performed to acquire ref values ​​in real time over time, from the start to the end of the subjective examination, while simultaneously conducting subjective examinations such as RG testing and weakest power testing. This is because the control unit 40 of the ophthalmic device 1 performs refract measurement of the eye under examination E using the refract measurement system 43, which is an objective measurement optical system, while the subjective examination is being conducted using the subjective measurement optical system 44, and also performs objective monitoring to monitor the ref values ​​as objective measurement information.

[0064] In step S16, a command is output to the examiner controller 30 to monitor and display objective measurement information at predetermined timings, including time intervals. Here, the objective measurement information to be monitored is, for example, information representing the relationship between the power of the corrective lens of the eye E being examined or the objective measurement value (equivalent spherical power calculated from the ref value) and the time since the start of the subjective examination, using a two-dimensional coordinate graph (see the two-dimensional coordinate graphs G, G', G'' in Figures 9, 10, and 11). The "predetermined timing" may be, for example, the timing when the spherical power is changed by the corrective lens in step S9, or the timing when the subject recognizes the sound of reading the visual target, or it may be displayed in real time each time a measurement is taken. The value to be displayed may also be the average value of the values ​​obtained during the time interval to be displayed.

[0065] In step S17, during the weakest power test measured in step S7 using LogMAR visual acuity values, the refractometer values ​​are monitored at least from the start to the end of the weakest power test, and a comparison is made to see if there are any differences or fluctuations in the refractometer values. Based on the comparison results, if there is a difference or fluctuation in the refractometer values ​​that exceeds a threshold, it is determined that there was accommodative intervention in the eye E during the weakest power test, and an alert is issued or feedback is provided to the eye examination. The feedback may include measures to reduce accommodative intervention, such as changing the spherical power of the corrective lens by -0.25D or encouraging the subject to look at distant objects.

[0066] Next, the weakest power test function of measuring LogMAR visual acuity values ​​using ophthalmic device 1 will be explained with reference to Figures 3, 9 to 12, etc.

[0067] First, prior art is defined as a system that does not have a means to determine accommodative intervention by the eye during the weakest power test, which uses a subjective measurement optical system to determine the weakest power at which the highest visual acuity value or any set visual acuity value can be read. In this prior art, it is assumed that the accommodative function of the lens of the eye is relaxed by introducing the fogging method into the subjective test, and in the final stage of the subjective test for distance power, the weakest power at which the highest visual acuity value can be obtained is determined, thereby determining a prescription value (subjective refractive value) that does not burden the subject.

[0068] However, during the weakest power test, if, for example, the eye being examined becomes unable to fixate due to examination fatigue, or if the spherical power is changed by changing the corrective lens, the accommodative function of the eye being examined may intervene. Therefore, if the test results are used directly as the subjective refractive value of the eye in a weakest power test where accommodative intervention by the eye being examined has occurred, the accuracy of the subjective refractive value test will decrease. In contrast, the prior art does not have a means to determine whether accommodative intervention by the eye being examined occurred during the subjective examination, and therefore it is not possible to determine or confirm whether accommodative intervention occurred by the eye being examined during the weakest power test.

[0069] In response to the request to determine accommodation intervention by the eye being examined during the weakest power test described above, the inventors focused on the fact that when the eye being examined E is in a relaxed state, the ciliary muscle of the lens does not react to changes in spherical power, etc., and fluctuations in the objective measurement value (equivalent spherical power) are suppressed. On the other hand, when accommodation is intervening in the eye being examined E, the ciliary muscle of the lens reacts to changes in spherical power, etc., and the objective measurement value (equivalent spherical power) fluctuates. In accordance with this focus, the control unit 40 performs objective measurement of the objective refractive characteristics of the eye being examined E using the objective measurement optical system (refract measurement system 43) during the weakest power test in which the weakest power is determined by the subjective measurement optical system 44. Along with this objective measurement, a configuration is adopted in which an objective monitor is performed to monitor the objective measurement information obtained by the measurement of objective refractive characteristics.

[0070] The following explains the weakest power test process by referring to the two-dimensional coordinate graph G of Monitor Display Example 1, which shows the relationship between the power of the corrective lens and the objective measurement value (equivalent spherical power) as shown in Figure 9. First, at the start of the weakest power test, the flowchart in Figure 3 proceeds from S1 to S2 to S3 to S4, and when the subjective test start setting in step S4 is completed, the initial refraction value is set to, for example, -1.0D when the power of the corrective lens is -0.50D, where the objective measurement value (equivalent spherical power) is -1.0D.

[0071] Then, in the flowchart of Figure 3, after adjustments are made from S4 to S5 by adding or replacing corrective lenses based on RG testing until the green and red targets on the RG chart 50 appear equally clear, the process proceeds to S6→S7→S8→S9. At the timing of the internal lens change in step S9, the power of the corrective lens is changed from -0.50D to -0.75D, which was determined in the RG test in step S5, and the first objective monitoring is performed to set the first REF value. Furthermore, in the flowchart of Figure 3, the process proceeds from S9 to S7→S8→S9. At the timing of the internal lens change in step S9, the power of the corrective lens is changed from -0.75D to -1.00D, and the second objective monitoring is performed to set the second REF value. Furthermore, in the flowchart of Figure 3, when progressing from S9 to S7 → S8 → S9, at the timing of the internal lens change in step S9, the power of the corrective lens is changed from -1.00D to -1.25D, and the third objective monitoring is performed to set the third refraction value.

[0072] As described above, a refract value characteristic graph is drawn by connecting each refract value, which is the measurement result from refract measurement, while changing the power of the corrective lens in increments of -0.25D (changing the power in the negative direction in Figure 9). At this time, if the subject eye E does not intervene in accommodation from the start to the end of the weakest power test, the refract value characteristic graph shown in the two-dimensional coordinate graph G in Figure 9 will be drawn, in which the initial refract value, the first refract value, the second refract value, and the third refract value will maintain -1.0D. On the other hand, when the power of the corrective lens is changed from -0.75D to -1.00D, for example, suppose that the subject eye E intervenes in accommodation due to the subject's anxiety during the test. In this case, in the two-dimensional coordinate graph G shown in Figure 9, the second refract value after the initial refract value and the first refract value will be the 2' refract value (black circle), which is a lower refract value than the second refract value (white circle) when the subject eye E did not intervene in accommodation. Subsequently, if the subject's examination tension is maintained, the ref value will decrease from the 3rd ref value (white circle) to the 3' ref value (black circle), resulting in a ref value characteristic graph where the ref value remains below the initial ref value of -1.0D. In such cases, step S17 determines that accommodative intervention has occurred in the subject eye E, and an alert is issued or feedback is provided to the optometry. This allows for the determination of the weakest power at which the highest visual acuity is obtained while preventing accommodative intervention so that the objective measurement value of the subject eye E does not fall below -1.0D.

[0073] Thus, when a refract value characteristic graph is drawn by connecting each refract value, which is the measurement result from the refract measurement, from the start to the end of the weakest power test, if the graph characteristic shows suppressed fluctuations in the refract value, it can be determined and confirmed that there was no accommodative intervention in the eye E being examined, simply by looking at the two-dimensional coordinate graph G. Conversely, if the graph characteristic shows fluctuations in the refract value, it can be determined and confirmed that there was accommodative intervention in the eye E being examined, simply by looking at the two-dimensional coordinate graph G.

[0074] As another embodiment of the two-dimensional coordinate graph G, Figure 10 shows the two-dimensional coordinate graph G' from monitor display example 2. In Figure 10, the horizontal axis represents time from the start of the subjective examination, rather than the power of the corrective lens. The objective measurement values ​​(equivalent spherical power) are plotted as time progresses, changing from RG test → cross cylinder test → ETDRS chart → binocular balance. At this time, as shown by the thick solid line in Figure 10, an alert is issued when the change or fluctuation of the objective measurement values ​​(equivalent spherical power) becomes large. The two-dimensional coordinate graph G' may also be color-coded or otherwise indicated to show the examination content at that time, such as the RG test, cross cylinder test, ETDRS chart, and binocular balance.

[0075] Figure 11 shows a two-dimensional coordinate graph G" from monitor display example 3. Similar to Figure 10, the horizontal axis of Figure 11 represents time from the start of the subjective examination. The objective measurement values ​​(equivalent spherical power) are plotted as time progresses through the RG test → cross cylinder test → ETDRS chart → binocular balance test. In the RG test and ETDRS chart, the spherical power S (sometimes cylindrical power C) at the time the lens was changed is indicated. Furthermore, in the RG test, the analysis of the gaze direction reveals which target the subject eye E is looking at (RG or RG), and this is also indicated. Here, the current spherical power S, cylindrical power C, and cylindrical axis angle A or SE (equivalent spherical power) may also be indicated at the time the lens spherical power S is changed. As shown by the thick solid line in Figure 11, alerts may be issued when the objective measurement values ​​(equivalent spherical power) change or fluctuate significantly, similar to Figure 10, or even for minor fluctuations.

[0076] The objective monitoring screen using one of the two-dimensional coordinate graphs G, G', or G'' is, for example, a screen that partially superimposes the two-dimensional coordinate graph G shown in Figure 9 onto the objective measurement screen for both eyes simultaneously displayed on the display unit 31 of the examiner controller 30, as shown in Figure 12. Alternatively, the objective monitoring screen may be a screen that superimposes or pops up one of the two-dimensional coordinate graphs G, G', or G'' shown in Figures 9 to 11 onto the subjective examination screen. Furthermore, the objective monitoring screen may be a screen that displays one of the two-dimensional coordinate graphs G, G', or G'' shown in Figures 9 to 11 independently of the subjective examination screen and the objective measurement screen.

[0077] As described above, during the weakest power test, objective measurement information obtained by measuring objective refractive characteristics (for example, one of the two-dimensional coordinate graphs G, G', or G'' shown in Figures 9 to 11) is displayed on a monitor, allowing the examiner to determine whether or not accommodative intervention occurred by the eye E being examined by viewing the displayed objective monitor screen. In addition, objective measurement information during subjective testing is acquired as data, and a large amount of objective measurement data is collected and classified in combination with other information about the eye E being examined (test fatigue, dry eye, etc.), allowing data analysis to be performed for each classified data group. This can lead to the investigation of the cause, such as when the eye E being unable to fixate due to test fatigue (unstable refractive index) or when visual acuity rapidly deteriorates due to dry eye (refractive index is stable, but visual acuity decreases). Furthermore, in the embodiment, an alert was issued based on changes and fluctuations in the equivalent spherical power, but an alert could also be issued based on changes in spherical power, cylindrical power, or, when the cylindrical power is somewhat large, changes in the cylindrical axis angle.

[0078] As explained above, the ophthalmic device 1 provides the following effects. (1) The system comprises a subjective measurement optical system 44 for measuring the subjective refractive value of the eye E under examination, an objective measurement optical system (refract measurement system 43) for measuring the objective refractive characteristics of the eye E under examination, and a control unit 40 for controlling the subjective measurement optical system 44 and the objective measurement optical system. During the weakest power test, when the subjective measurement optical system 44 is used to determine the weakest power at which the highest visual acuity value or any set visual acuity value can be read, the control unit 40 performs objective measurement of the objective refractive characteristics of the eye E under examination using the objective measurement optical system, and also performs objective monitoring to monitor the objective measurement information (equivalent spherical power) acquired by the measurement. Therefore, during the weakest power test, it is possible to determine whether or not there was accommodation intervention by the eye E under examination.

[0079] (2) The ophthalmic device 1 is an objective measuring device with subjective function, equipped with a subjective measuring optical system 44 and an objective measuring optical system (refract measurement system 43). The objective measuring optical system has the function of measuring the objective refractive characteristics of the eye E under examination simultaneously in both eyes. Therefore, during subjective examinations, cloud control and binocular balance tests can be performed quickly and in a short amount of time.

[0080] (3) The control unit 40 monitors the objective measurement values ​​(equivalent spherical power) at least from the start to the end of the weakest power test, and issues an alert or provides feedback to the eye examination content based on the comparison results of the difference or fluctuation of the objective measurement values. This makes it possible to inform the examiner if there has been accommodation intervention by the eye E during the weakest power test, or to improve the accuracy of the weakest power test by processing to reflect the subjective refractive value in which accommodation intervention occurred in the detection result.

[0081] (4) The subjective measurement optical system 44 uses an ETDRS chart (decimal visual acuity value chart 51, fractional visual acuity value chart 52, etc.) as the visual target used during the weakest power test to determine the weakest power. The control unit 40 uses the LogMAR visual acuity value measured using the ETDRS chart as the highest visual acuity value. Therefore, statistical calculations such as the mean and standard deviation can be performed using the measured LogMAR visual acuity value.

[0082] (5) The control unit 40 determines the weakest power at which the highest visual acuity can be read, based on the highest visual acuity obtained by changing the spherical power by predetermined values ​​using corrective lenses, and when the determined weakest power is used as the subjective refractive value in the subjective eye examination, it outputs a command to perform a binocular balance test after the subjective refractive values ​​have been determined for both eyes of the eye being examined E. Therefore, a binocular balance test can be performed immediately after the subjective refractive values ​​have been determined for both eyes of the eye being examined E.

[0083] (6) When the control unit 40 performs a binocular balance test while the subject eye E is simultaneously viewing a target with both eyes, if it determines that the binocular balance is ambiguous, it will check the cause by either occluding one eye of the subject eye E or by leaving both eyes open. Therefore, when performing a binocular balance test, the appropriate method can be selected from the two methods to investigate the cause of the ambiguous binocular balance.

[0084] (7) The system includes an examiner controller 30 that accepts input operations from the examiner and outputs control signals to the control unit 40. The control unit 40 displays objective measurement information on the monitor as information that represents the relationship between the power of the corrective lens of the eye E being examined and / or the objective measurement value (equivalent spherical power) and the subjective measurement time, using one of the two-dimensional coordinate graphs G, G', or G''. When objective monitoring is performed during the weakest power test, the control unit 40 outputs a command to display one of the two-dimensional coordinate graphs G, G', or G'' on the display unit 31 of the examiner controller 30. Therefore, during the weakest power test, the examiner can easily determine whether or not there has been accommodation intervention by the eye E being examined by looking at one of the two-dimensional coordinate graphs G, G', or G'' displayed on the examiner controller 30 in their hand.

[0085] (8) When objective monitoring is performed during the weakest frequency test, the control unit 40 outputs a command to the examiner controller 30 to monitor and display objective measurement information at predetermined timings, including time intervals. Therefore, if the time interval is set to be very short, the change in objective measurement values ​​can be displayed on the display unit 31 of the examiner controller 30 in near real time, and if the time interval is set to be long or to a specific timing, the processing load on the control unit 40 can be reduced compared to when the time interval is set to be very short.

[0086] (9) When the spherical power is changed by the corrective lens during the weakest power test, the control unit 40 outputs a command to the examiner controller 30 to monitor and display the objective measurement information acquired at the time the spherical power was changed. Therefore, during the weakest power test, the processing load for generating any of the two-dimensional coordinate graphs G, G', and G'' is reduced, while the objective measurement value (equivalent spherical power) at the time when accommodation intervention by the eye E is highly likely to occur can be reflected in any of the two-dimensional coordinate graphs G, G', and G''.

[0087] (10) When the control unit 40 recognizes the voice of the subject reading the visual target during the weakest power test, it outputs a command to the examiner controller 30 to monitor and display the objective measurement information acquired at the time the voice was recognized. Therefore, during the weakest power test, the processing load for generating any of the two-dimensional coordinate graphs G, G', and G'' can be reduced, while the objective measurement value (equivalent spherical power) at the time when accommodation intervention by the eye E is highly likely can be reflected in any of the two-dimensional coordinate graphs G, G', and G''.

[0088] The ophthalmic device of the present invention has been described above based on Example 1. However, the specific configuration is not limited to Example 1. Modifications and additions to the design are permitted as long as they do not deviate from the gist of the invention as described in each claim of the patent. For example, a configuration in which objective measurements are performed while visual acuity is measured by displaying a visual target on a display or printed on paper, or a configuration in which objective measurements are performed while visual acuity is measured using a device equipped with a visual target observable by both eyes inside the device.

[0089] In Example 1, an example of a binocular open-type ophthalmic device 1 was shown, which is capable of objectively measuring the ocular characteristics of the left and right eye E individually. However, the ophthalmic device is not limited to this, and a monocular type ophthalmic device that measures the ocular characteristics of one eye at a time may also be used. In other words, the ophthalmic device may be equipped with an objective measurement optical system that objectively measures the ocular characteristics of the left eye E and the ocular characteristics of the right eye E, one at a time.

[0090] In Example 1, the subjective measurement optical system 44 was shown as an example in which the target used during the weakest power test to determine the weakest power was an ETDRS chart. However, the target used during the weakest power test is not limited to an ETDRS chart for the subjective measurement optical system, and examples of using targets other than the ETDRS chart are also possible.

[0091] In Example 1, the objective measurement information was shown as monitor display information representing the relationship between the objective measurement value (equivalent spherical power) and the power of the corrective lens of the eye E being examined, using a two-dimensional coordinate graph G, and the relationship between the objective measurement value (equivalent spherical power) and the time elapsed since the start of the subjective examination, using two-dimensional coordinate graphs G' and G''. However, objective measurement information is not limited to information using two-dimensional coordinate graphs. For example, the equivalent spherical power may be displayed numerically, and the monitor display information may change color when the numerical value changes above a threshold. In addition, audio information (information on whether or not adjustment intervention was performed) may be added to the monitor display information using graphs or numerical values.

[0092] In Example 1, an example was shown in which a command to monitor and display objective measurement information was output to the examiner controller 30 at the timing when the spherical frequency was changed or when sound was recognized during the weakest frequency test. However, the timing of outputting the command to monitor and display objective measurement information to the examiner controller is not limited to the above timings. For example, a command to monitor and display objective measurement information could be output to the examiner controller at all times during the weakest frequency test. Alternatively, a command to monitor and display objective measurement information could be output to the examiner controller at pre-set time intervals during the weakest frequency test. [Explanation of Symbols]

[0093] 1 Ophthalmology equipment 30 Examiner's Controller 31 Display section 40 Control Unit 41 Observation System 42 Visual target projection system 43. Refractometer (objective measurement optical system) 44 Subjective Measurement Optical System 47. Keratometry system (objective measurement optical system) 51. Decimal point visual acuity scale (ETDRS chart) 52-Fractional Visual Acuity Scale (ETDRS Chart)

Claims

1. The system comprises a subjective measurement optical system for measuring the subjective refractive value of the eye under examination, an objective measurement optical system for measuring the objective refractive characteristics of the eye under examination, and a control unit for controlling the subjective measurement optical system and the objective measurement optical system. During a weakest power test, in which the subjective measurement optical system determines the weakest power at which the highest visual acuity value or any set visual acuity value can be read, the control unit performs objective measurement of the subject's eye using the objective measurement optical system, and also performs objective monitoring to monitor the objective measurement information acquired by the measurement. At least from the start to the end of the weakest power test, objective measurement values ​​acquired in real time over time are monitored concurrently with the implementation of the weakest power test, and a comparison is made to determine whether there are differences or fluctuations in the objective measurement values. Based on the comparison results, if there is a difference or fluctuation above a threshold in the objective measurement values, it is determined that there was accommodative intervention by the eye being examined during the weakest power test. The system includes an examiner controller that receives input operations from the examiner and outputs control signals to the control unit, The control unit uses the objective measurement information as information that represents the relationship between the objective measurement value and the power of the corrective lens of the eye being examined, using a two-dimensional coordinate graph. When performing the objective monitoring during the weakest degree test, a command is output to display the two-dimensional coordinate graph on the display unit of the examiner's controller. An ophthalmic device characterized by the following features.

2. The system comprises a subjective measurement optical system for measuring the subjective refractive value of the eye under examination, an objective measurement optical system for measuring the objective refractive characteristics of the eye under examination, and a control unit for controlling the subjective measurement optical system and the objective measurement optical system. During a weakest power test, in which the subjective measurement optical system determines the weakest power at which the highest visual acuity value or any set visual acuity value can be read, the control unit performs objective measurement of the subject's eye using the objective measurement optical system, and also performs objective monitoring to monitor the objective measurement information acquired by the measurement. At least from the start to the end of the weakest power test, objective measurement values ​​acquired in real time over time are monitored concurrently with the implementation of the weakest power test, and a comparison is made to determine whether there are differences or fluctuations in the objective measurement values. Based on the comparison results, if there is a difference or fluctuation above a threshold in the objective measurement values, it is determined that there was accommodative intervention by the eye being examined during the weakest power test. The system includes an examiner controller that receives input operations from the examiner and outputs control signals to the control unit, The control unit uses the objective measurement information as information that represents the relationship between the objective measurement value and the subjective measurement time of the eye being examined, using a two-dimensional coordinate graph. When performing the objective monitoring during the weakest degree test, a command is output to display the two-dimensional coordinate graph on the display unit of the examiner's controller. An ophthalmic device characterized by the following features.

3. In the ophthalmic device described in Claim 2, The aforementioned objective measurement information is further enhanced by adding information on the spherical power of the lens to the information representing the relationship between the objective measurement value and the subjective measurement time of the eye being examined, using a two-dimensional coordinate graph. An ophthalmic device characterized by the following features.

4. In an ophthalmic device as described in any one of Claims 1 to 3, The ophthalmic device is an objective measuring device with a subjective function, comprising a subjective measuring optical system and an objective measuring optical system. The aforementioned objective measurement optical system has the function of simultaneously measuring the objective refractive characteristics of the eye under examination for both eyes. An ophthalmic device characterized by the following features.

5. An ophthalmic device according to any one of Claims 1 to 3, If the control unit determines that accommodation intervention occurred in the eye being examined during the weakest power test, it issues an alert or provides feedback to the eye examination results. An ophthalmic device characterized by the following features.

6. In an ophthalmic device as described in any one of Claims 1 to 3, The aforementioned subjective measurement optical system uses an ETDRS chart as the target used during the weakest power test to determine the weakest power. The control unit sets the LogMAR visual acuity value measured using the ETDRS chart as the highest visual acuity value. An ophthalmic device characterized by the following features.

7. In the ophthalmic device described in Claim 6, The control unit determines the weakest power at which the highest visual acuity value can be read, based on the highest visual acuity value obtained by changing the spherical power by predetermined values ​​using the corrective lens. When the weakest power is used as the subjective refractive value in the subjective eye examination, after the subjective refractive values ​​are determined for both eyes of the subject, a command is output to perform a binocular balance test. An ophthalmic device characterized by the following features.

8. In the ophthalmic device described in Claim 7, The control unit performs the binocular balance test, which adjusts the balance of visual acuity between the left and right eyes while the subject's eyes simultaneously view a target. An ophthalmic device characterized by the following features.

9. In an ophthalmic device as described in any one of Claims 1 to 3, When the control unit performs the objective monitoring during the weakest frequency test, it outputs a command to the examiner's controller to monitor and display the objective measurement information at predetermined timings, including time intervals. An ophthalmic device characterized by the following features.

10. In the ophthalmic device described in Claim 9, When the control unit changes the spherical power using a corrective lens during the weakest power test, it outputs a command to the examiner's controller to monitor and display the objective measurement information acquired at the time the spherical power was changed. An ophthalmic device characterized by the following features.

11. In the ophthalmic device described in Claim 9, When the control unit recognizes the sound of the subject reading the visual target during the weakest power test, it outputs a command to the examiner's controller to monitor and display the objective measurement information acquired at the time the sound was recognized. An ophthalmic device characterized by the following features.

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