Ophthalmic equipment and ophthalmic programs

Abstract

To provide an ophthalmologic apparatus capable of easily determining ametropia of a subject eye, and an ophthalmologic program.SOLUTION: The ophthalmologic apparatus for objectively measuring the eye refractive power of a subject eye comprises: acquisition means for acquiring at least a spherical refractive power and a cylindrical refractive power as the eye refractive power of the subject eye, the acquisition means acquiring a first cylindrical refractive power of a plus code and a first spherical refractive power corresponding to the first cylindrical refractive power and acquiring a second cylindrical refractive power of a minus code and a second spherical refractive power corresponding to the second cylindrical refractive power; determination means which determines ametropia based on the first spherical refractive power or the second spherical refractive power with a maximum absolute value, and a predetermined threshold value being a determination reference of ametropia for the subject eye; and control means which outputs a result of the determination by the determination means.SELECTED DRAWING: Figure 1

Description

Technical Field

[0004] , , , , , ,

[0001] The present disclosure relates to an ophthalmic apparatus for objectively measuring the refractive power of an eye to be examined, and an ophthalmic program.

Background Art

[0002] As an ophthalmic apparatus, for example, an eye refractive power measuring apparatus is known. For example, as an eye refractive power measuring apparatus, there is known one that objectively measures the refractive power of an eye to be examined by projecting a measurement light beam onto the fundus of the eye to be examined and receiving the reflected light beam from the fundus with a light receiving element (see Patent Document 1). Further, for example, as an eye refractive power measuring apparatus, there is known an objective ophthalmoscope of a photorefraction method that objectively measures the refractive power of an eye to be examined from the ratio of the reflected light from the fundus of the eye to be examined in the pupil (see Patent Document 2).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the above-described refractive power measuring device, the refractive power of the eye being examined can be obtained in two ways: a positive reading where the cylindrical refractive power is expressed with a positive sign, and a negative reading where the cylindrical refractive power is expressed with a negative sign. However, the measurement results are often output using only one of these readings. For example, examiners determine whether the eye being examined has a refractive error (e.g., myopia, hyperopia, etc.) based on the measurement results, but depending on the measurement results and how they are read, refractive errors may be missed. In particular, screening tests are conducted for young children, such as 3-year-olds, with the aim of early detection of refractive errors, and such missed refractive errors could be problematic.

[0005] In light of the above-mentioned problems, this disclosure aims to provide an ophthalmic device and an ophthalmic program that can easily determine refractive errors in the eye being examined. [Means for solving the problem]

[0006] To solve the above problems, the present invention is characterized by having the following configuration. (1) An ophthalmic device according to a first aspect of the present disclosure is an ophthalmic device for objectively measuring the refractive power of an eye under examination, comprising: an acquisition means for acquiring at least spherical refractive power and cylindrical refractive power as the refractive power of the eye under examination, which acquires a first cylindrical refractive power with a positive sign and a first spherical refractive power corresponding to the first cylindrical refractive power, and also acquires a second cylindrical refractive power with a negative sign and a second spherical refractive power corresponding to the second cylindrical refractive power; a determination means for determining a refractive error based on the spherical refractive power having the maximum absolute value among the first and second spherical refractive powers and a predetermined threshold which is a criterion for determining refractive errors for the eye under examination; and a control means for outputting the determination result from the determination means. (2) An ophthalmic device according to a second aspect of the present disclosure is an ophthalmic device for objectively measuring the refractive power of an eye under examination, comprising: an acquisition means for acquiring at least spherical refractive power and cylindrical refractive power as the refractive power of the eye under examination, which acquires a first cylindrical refractive power with a positive sign and a first spherical refractive power corresponding to the first cylindrical refractive power, and also acquires a second cylindrical refractive power with a negative sign and a second spherical refractive power corresponding to the second cylindrical refractive power; and a control means for outputting the refractive power of the eye under examination, which outputs the spherical refractive power having the maximum absolute value among the first spherical refractive power and the second spherical refractive power. (3) An ophthalmic program according to a third aspect of the present disclosure is characterized by causing a processor to execute an acquisition step of acquiring at least spherical refractive power and cylindrical refractive power as the refractive power of an eye under examination, the acquisition step of acquiring a first cylindrical refractive power with a positive sign and a first spherical refractive power corresponding to the first cylindrical refractive power, as well as a second cylindrical refractive power with a negative sign and a second spherical refractive power corresponding to the second cylindrical refractive power; a determination step of determining a refractive error based on the spherical refractive power having the maximum absolute value among the first and second spherical refractive powers and a predetermined threshold which is a criterion for determining refractive errors for the eye under examination; and a control step of outputting the determination result from the determination step. (4) An ophthalmic program according to a fourth aspect of the present disclosure is characterized by causing a processor to execute an acquisition step of acquiring at least spherical refractive power and cylindrical refractive power as the refractive power of an eye under examination, which includes acquiring a first cylindrical refractive power with a positive sign and a first spherical refractive power corresponding to the first cylindrical refractive power, as well as a second cylindrical refractive power with a negative sign and a second spherical refractive power corresponding to the second cylindrical refractive power; and a control step of outputting the refractive power of the eye under examination, which includes outputting the spherical refractive power that has the maximum absolute value among the first spherical refractive power and the second spherical refractive power. [Brief explanation of the drawing]

[0007] [Figure 1] This is a diagram illustrating the configuration of ophthalmic equipment. [Figure 2] This diagram shows the measurement light source as viewed from the front. [Figure 3] This is a diagram illustrating the photorefraction method. [Figure 4] This is a schematic diagram of the control system in an ophthalmic device. [Figure 5] This diagram illustrates the operation of the measurement light source. [Figure 6] This is an example of a display screen. [Figure 7] This is an example of a display screen when there is no refractive error in the eye being examined. [Modes for carrying out the invention]

[0008] <Overview> An overview of the ophthalmic apparatus according to this embodiment is described below. The items classified in <> below can be used independently or in relation to each other.

[0009] The ophthalmic device of this embodiment is an ophthalmic device for objectively measuring the refractive power of an eye under examination. For example, the refractive power of the eye under examination may include at least spherical refractive power (S) and cylindrical refractive power (C). Of course, in addition to spherical refractive power and cylindrical refractive power, the astigmatism axis angle (A) may also be measured as part of the refractive power of the eye under examination. Furthermore, for example, the equivalent spherical refractive power (SE) based on the spherical refractive power and cylindrical refractive power may also be measured.

[0010] The ophthalmic device of this embodiment may include a measurement means for objectively measuring the refractive power of the eye under examination. For example, the ophthalmic device may include a measurement means for measuring the refractive power of the eye under examination using a method different from the photorefraction method. In this case, the measurement means may have a configuration in which a pattern index is projected as measurement light onto the fundus of the eye under examination, and the reflected light reflected by the fundus is detected by a detector. For example, the reflected light may be detected as a ring image. Alternatively, the reflected light may be detected by a Shack-Hartmann sensor. Furthermore, for example, the ophthalmic device may include a measurement means for measuring the refractive power of the eye under examination using the photorefraction method. In this case, the measurement means may have a configuration in which a non-pattern index is projected as measurement light onto the fundus of the eye under examination, and the reflected light reflected by the fundus is detected by a detector. For example, the state of the light beam in the pupil of the eye under examination (e.g., the ratio of light beam in the pupil) may be detected.

[0011] For example, the photorefraction measurement method described above may include a light-emitting optical system (e.g., light-emitting optical system 10) and a light-receiving optical system (e.g., light-receiving optical system 20). For example, the light-emitting optical system and the light-receiving optical system may each be composed of different optical components, or they may share at least some optical components.

[0012] For example, the light projection optical system only needs to have a configuration that includes at least a measurement light source. For example, the light projection optical system may have a plurality of measurement light sources (e.g., measurement light source 13) arranged in the meridian direction (radial direction) with respect to the optical axis center, and the measurement light beam emitted from the plurality of measurement light sources may be irradiated onto the fundus of the eye under examination. For example, the plurality of measurement light sources may each be controlled independently. For example, the turning on and off, the adjustment of the light intensity, etc. of each measurement light source may be controlled independently. Also, the plurality of measurement light sources may be arranged separately from each other with respect to at least three meridian directions with respect to the optical axis center. For example, by arranging the measurement light sources in at least three meridian directions, the refractive power of the eye, including spherical refractive power, cylindrical refractive power, astigmatism axis angle, etc., can be measured. Note that the number of meridian directions in which the measurement light sources are arranged can be any number of meridian directions (e.g., 1 meridian direction, 2 meridian directions, 3 meridian directions, 4 meridian directions, etc.). Also, it is sufficient that at least one measurement light source is arranged in each meridian direction.

[0013] For example, the light-receiving optical system may have at least one detector. For instance, the light-receiving optical system may detect the reflected light of the measurement light reflected by the fundus of the eye being examined using a detector (e.g., detector 21).

[0014] <Acquisition method> The ophthalmic device of the present embodiment may include acquisition means (for example, the control unit 80). For example, the acquisition means is acquisition means for acquiring at least the spherical refractive power and the cylindrical refractive power as the refractive power of the subject eye, and acquires the first cylindrical refractive power with a plus sign and the first spherical refractive power corresponding to the first cylindrical refractive power, and also acquires the second cylindrical refractive power with a minus sign and the second spherical refractive power corresponding to the second cylindrical refractive power. For example, in the refractive power of the subject eye, the cylindrical refractive power can be acquired in two patterns: when represented by a plus sign (in other words, when read as plus), and when represented by a minus sign (in other words, when read as minus). For example, depending on the plus or minus reading of the cylindrical refractive power, the spherical refractive power corresponding to the cylindrical refractive power changes. Therefore, for example, the first spherical refractive power corresponding to the first cylindrical refractive power with a plus sign and the second spherical refractive power corresponding to the second cylindrical refractive power with a minus sign are represented by different values from each other.

[0015] Note that, for example, the plus and minus readings of the cylindrical refractive power of the subject eye are determined by the refractive power in the meridian direction of the subject eye. More specifically, for example, among the two meridian directions of the subject eye, namely the meridian with the strongest refractive power (the strong principal meridian) and the meridian with the weakest refractive power (the weak principal meridian), depending on which meridian direction's refractive power the cylindrical refractive power of the subject eye is represented by, the cylindrical refractive power is acquired in two patterns of plus and minus readings.

[0016] For example, the acquisition means may be another ophthalmic device different from the present embodiment, and acquire at least the spherical refractive power and the cylindrical refractive power by receiving the measurement results measured using an ophthalmic device capable of objectively measuring the refractive power of the subject eye. That is, the ophthalmic device of the present embodiment may function as an information analysis device. Of course, the ophthalmic device of the present embodiment may include the aforementioned measurement means. In this case, for example, the acquisition means may acquire at least the spherical refractive power and the cylindrical refractive power based on the measurement results by the measurement means.

[0017] <Determination means> The ophthalmic device of this embodiment may include a determination unit (for example, the control unit 80). For example, the determination unit determines refractive abnormality based on the spherical refractive power with the largest absolute value among the first spherical refractive power corresponding to the first cylindrical refractive power with a plus sign and the second spherical refractive power corresponding to the second cylindrical refractive power with a minus sign, and a predetermined threshold that is a criterion for refractive abnormality of the eye to be examined. At this time, for example, based on the first spherical refractive power corresponding to the first cylindrical refractive power with a plus sign and the second spherical refractive power corresponding to the second cylindrical refractive power with a minus sign, the spherical refractive power with the largest absolute value may be used for determining refractive abnormality. For example, the determination unit may determine that there is a refractive abnormality when the spherical refractive power with the largest absolute value exceeds a predetermined threshold. Also, for example, the determination unit may determine that there is no refractive abnormality when the spherical refractive power with the largest absolute value does not exceed a predetermined threshold. For example, by using the spherical refractive power with the largest absolute value, even in a case where the spherical refractive power corresponding to the reading of one cylindrical refractive power does not exceed a predetermined threshold, but the spherical refractive power corresponding to the reading of the other cylindrical refractive power exceeds a predetermined threshold, refractive abnormality can be easily determined.

[0018] For example, the determination unit may determine refractive abnormality by comparing only the spherical refractive power with the largest absolute value among the first spherical refractive power and the second spherical refractive power with a predetermined threshold.

[0019] For example, when the determination unit compares only the spherical refractive power with the largest absolute value with the threshold, the spherical refractive power with the largest absolute value may be obtained by directly comparing the first spherical refractive power and the second spherical refractive power. As an example, when the first spherical refractive power is -2.50 D and the second spherical refractive power is -1.50 D, the second spherical refractive power -2.50 D with the largest absolute value may be obtained by comparing them with each other.

[0020] Furthermore, for example, if the determination means compares only the spherical refractive power with the maximum absolute value with a threshold, the spherical refractive power with the maximum absolute value may be obtained based on the sign of the first equivalent spherical refractive power obtained by the first spherical refractive power and the first cylindrical refractive power. Alternatively, the spherical refractive power with the maximum absolute value may be obtained based on the sign of the second equivalent spherical refractive power obtained by the second spherical refractive power and the second cylindrical refractive power. Note that, for example, the first equivalent spherical refractive power and the second equivalent spherical refractive power will have the same value, so either can be used. As an example, if the equivalent spherical refractive power has a negative sign, the first spherical refractive power corresponding to the cylindrical refractive power with a positive sign may be obtained as the spherical refractive power with the maximum absolute value. Also, as an example, if the equivalent spherical refractive power has a positive sign, the second spherical refractive power corresponding to the cylindrical refractive power with a negative sign may be obtained as the spherical refractive power with the maximum absolute value. For example, the determination means may obtain the spherical refractive power that has the maximum absolute value by obtaining a spherical refractive power corresponding to a reading of the cylindrical refractive power, which has the opposite sign to the sign of the equivalent spherical refractive power.

[0021] For example, the determination means may determine refractive anomalies by comparing both the first spherical refractive power and the second spherical refractive power with a predetermined threshold. As an example, the determination of refractive anomalies may be made by comparing both the first spherical refractive power and the second spherical refractive power with a predetermined threshold, and if at least one of the first or second spherical refractive power exceeds the predetermined threshold. Note that either the first or second spherical refractive power corresponds to the spherical refractive power with the maximum absolute value, and refractive anomalies can be easily determined by comparing both of these with a threshold.

[0022] For example, the predetermined threshold may be a criterion established to determine whether a refractive error is myopia or hyperopia. For example, the predetermined threshold may be at least one specific value, or a specific tolerance range, etc.

[0023] For example, the predetermined threshold may be a fixed value set in advance. For example, in this case, the predetermined threshold may be a value set in advance based on an experiment or simulation. Alternatively, for example, the predetermined threshold may be an arbitrary value set based on an operation signal. For example, in this case, the operation signal may be output by the examiner operating the operation means (e.g., controller 81). Alternatively, for example, in this case, the operation signal may be output by using an external storage means (e.g., an SD card, USB memory, server, cloud, etc.) and reading data stored in the external storage means.

[0024] <Setting method> The ophthalmic apparatus of this embodiment may include setting means (for example, a control unit 80). For example, the setting means sets whether to output a first cylindrical refractive power with a positive sign or a second cylindrical refractive power with a negative sign as the cylindrical refractive power of the eye under examination. For example, since the cylindrical refractive power of the eye under examination can be obtained in two patterns, a positive reading and a negative reading, the output method may be set to prioritize one of the readings.

[0025] For example, the setting means may set whether to output the first cylindrical refractive force or the second cylindrical refractive force based on a selection signal of either the first or second cylindrical refractive force input by the operator using the control means. Alternatively, for example, the setting means may automatically set whether to output the first or second cylindrical refractive force based on the determination result of the determination means described later.

[0026] <Control means> The ophthalmic apparatus of this embodiment may include control means (e.g., a control unit 80). For example, the control means outputs the determination result of the determination means. For example, the determination result only needs to be able to indicate a refractive error in the eye being examined. For example, the determination result may directly or indirectly indicate that there is a refractive error, or directly or indirectly indicate that there is no refractive error. Of course, for example, the determination result may include both indicating that there is a refractive error and indicating that there is no refractive error. This allows the examiner to easily determine the refractive error, and as a result, the chances of missing a refractive error in the eye being examined can be reduced.

[0027] For example, the control means may directly output the determination result of the determination means. In this case, the determination result may be whether the first spherical refractive power or the second spherical refractive power of the eye under examination (in other words, the spherical refractive power with the maximum absolute value) exceeds a predetermined threshold, which is the criterion for determining refractive error, or whether it does not exceed that threshold.

[0028] Furthermore, for example, the control means may output various information based on the determination result as the determination result of the determination means. In this case, the determination result may be output as notification information to inform the examiner of the presence or absence of refractive errors. For example, the notification information may be at least one of the following: information indicating the presence or absence of refractive errors, information indicating the degree of refractive errors (e.g., numerical values ​​or evaluation indicators), etc. Also, in this case, the determination result may be output as guidance information to guide the examiner. For example, the guidance information may be at least one of the following: information indicating the end of the eye examination, information indicating the examiner's next action, information indicating instructions to the subject, etc.

[0029] For example, the control means may control the display means and cause the display means to display the judgment result. Alternatively, the control means may control the sound generation means (for example, a speaker) and cause the sound generation means to generate the judgment result as sound. Alternatively, the control means may control the notification means (for example, a lamp) and indicate the judgment result by lighting or flashing the notification means. Alternatively, the control means may control the printing means (for example, a printer) and cause the printing means to print the judgment result. Alternatively, the control means may control the external storage means (for example, a memory or server) and transmit the judgment result to the external storage means. Of course, the control means may also perform a combination of these controls, or perform controls different from these.

[0030] Furthermore, for example, when the control means controls the display means, a message may be displayed on the display means as the determination result. Alternatively, the determination result may be indicated by highlighting the screen on the display means. For example, this could be at least one of the following: inverting or changing the screen colors, flashing the screen, changing the display size, etc. Alternatively, the determination result may be indicated by displaying a sign (for example, at least one of a window, mark, icon, character, number, symbol, etc.) on the display means. Of course, the determination result may also be indicated by further highlighting such a sign.

[0031] In this embodiment, the control means may output the refractive power of the eye under examination. In this case, the control means may output the spherical refractive power with the maximum absolute value among the first spherical refractive power corresponding to the first cylindrical refractive power with a positive sign and the second spherical refractive power corresponding to the second cylindrical refractive power with a negative sign. In this case, for example, the spherical refractive power with the maximum absolute value may be used for output based on the first spherical refractive power corresponding to the first cylindrical refractive power with a positive sign and the second spherical refractive power corresponding to the second cylindrical refractive power with a negative sign. That is, the spherical refractive power with the larger absolute value among the first and second spherical refractive powers may be used for output. In this case, since the spherical refractive power with the maximum absolute value can be confirmed as the spherical refractive power of the eye under examination, it is possible to easily determine whether the eye under examination has a refractive error and reduce the chances of missing a refractive error. Of course, the control means may output not only the spherical refractive power with the maximum absolute value, but also the corresponding cylindrical refractive power, equivalent spherical refractive power, astigmatism axis angle, etc.

[0032] In this embodiment, the control means may output the refractive power of the eye under examination along with the determination result. In this case, the control means for outputting the refractive power of the eye under examination and the control means for outputting the determination result of the eye under examination may be used together, or they may be provided separately.

[0033] For example, if the determination means determines that the spherical refractive power with the maximum absolute value is below a predetermined threshold, the control means may output the cylindrical refractive power with the sign set by the setting means and the spherical refractive power corresponding to the cylindrical refractive power with the sign set by the setting means as the refractive power of the eye. In other words, the control means may output the refractive power of the eye according to either the positive or negative reading setting of the cylindrical refractive power by the setting means. Also, for example, if the determination means determines that the spherical refractive power with the maximum absolute value is above a predetermined threshold, the control means may output the spherical refractive power with the maximum absolute value and the cylindrical refractive power corresponding to the spherical refractive power with the maximum absolute value as the refractive power of the eye, regardless of the sign set by the setting means. In other words, regardless of whether the setting means sets the positive or negative reading of the cylindrical refractive power, the control means may output the refractive power of the eye according to the reading of the spherical refractive power with the maximum absolute value and the cylindrical refractive power corresponding to this spherical refractive power. This makes it easier for examiners to determine whether the spherical refractive power of the eye being examined exceeds the standard, and to easily judge refractive errors in the eye being examined.

[0034] This disclosure is not limited to the apparatus described in this embodiment. For example, terminal control software (program) that performs the functions of the above embodiment can be supplied to a system or apparatus via a network or various storage media, and the control device (e.g., CPU) of the system or apparatus can read and execute the program.

[0035] For example, such terminal control software may cause a processor to execute an acquisition step of acquiring at least spherical refractive power and cylindrical refractive power as the refractive power of the eye under examination, which includes acquiring a first cylindrical refractive power with a positive sign and a first spherical refractive power corresponding to the first cylindrical refractive power, as well as a second cylindrical refractive power with a negative sign and a second spherical refractive power corresponding to the second cylindrical refractive power; a determination step of determining refractive error based on the spherical refractive power with the maximum absolute value among the first and second spherical refractive powers and a predetermined threshold which is a criterion for determining refractive error in the eye under examination; and a control step of outputting the determination result from the determination step. As an example, this may be executed by a processor installed in an ophthalmic device.

[0036] Furthermore, for example, such terminal control software may cause a processor to execute an acquisition step of acquiring at least spherical refractive power and cylindrical refractive power as the refractive power of the eye under examination, which includes acquiring a first cylindrical refractive power with a positive sign and a first spherical refractive power corresponding to the first cylindrical refractive power, as well as a second cylindrical refractive power with a negative sign and a second spherical refractive power corresponding to the second cylindrical refractive power; and a control step of outputting the refractive power of the eye under examination, which includes outputting the spherical refractive power with the maximum absolute value among the first and second spherical refractive powers. As an example, this may be executed by a processor mounted on an ophthalmic device.

[0037] <Examples> The following describes one embodiment of the ophthalmic device in this embodiment. For example, Figure 1 is a diagram illustrating the configuration of the ophthalmic device. In this embodiment, the explanation will be given using a configuration in which the light-emitting optical system and the light-receiving optical system are used for both left and right eye measurements. In other words, the explanation will be given using a case in which the left and right eye measurements of the eye are performed by one light-emitting optical system and one light-receiving optical system.

[0038] <Appearance of the device> For example, the ophthalmic device 1 objectively measures the refractive power of the eye under examination using a photorefraction method. For example, a configuration for objectively measuring the refractive power of the eye under examination using a photorefraction method refers to a configuration in which the refractive power of the eye under examination is objectively measured from the ratio of reflected light from the fundus of the eye under examination to the pupil. For example, in this embodiment, the ophthalmic device 1 includes a housing 2. For example, the housing 2 houses an optical system (e.g., a light-emitting optical system 10, a light-receiving optical system 20) for objectively measuring the refractive power of the eye under examination using a photorefraction method.

[0039] <Measurement optical system> For example, the ophthalmic device 1 includes a light-emitting optical system 10 and a light-receiving optical system 20. In this embodiment, for example, the light-emitting optical system 10 includes a measuring light source 13. Of course, for example, the light-emitting optical system 10 may consist only of the measuring light source 13. For example, the light-receiving optical system 20 includes a detector 21 (e.g., a CCD, etc.) and a light-receiving objective optical system 25.

[0040] For example, the presentation window 3 transmits the measurement light emitted from the measurement light source 13 in the light projection optical system 10. Therefore, the measurement light is irradiated onto the eye E being examined via the presentation window 3. For example, the presentation window 3 is covered with a transparent panel to prevent the intrusion of dust and other debris. For example, a transparent material such as acrylic resin or a glass plate can be used as the transparent panel.

[0041] Figure 2 shows the measurement light source 13 as viewed from the front (along the optical axis) (as seen by the subject). For example, a red LED (light-emitting diode) that emits near-infrared light can be used as the measurement light source 13. Of course, different types of light sources may be used.

[0042] For example, in this embodiment, the measurement light source 13 also serves as a light source for illuminating the anterior segment of the eye under examination. Of course, a separate, dedicated light source for illuminating the anterior segment image may also be provided. Also, for example, in this embodiment, the detector 21 also serves as a detector that captures the anterior segment image illuminated by the anterior segment illumination light source. Of course, a separate, dedicated detector for capturing the anterior segment image may also be provided. For example, the captured anterior segment image is displayed on the display 11.

[0043] For example, in this embodiment, the measurement light source 13 also serves as the fixation lamp for fixing the eye under examination. Of course, a separate fixation lamp dedicated to fixing the eye under examination may also be provided. For example, if a fixation lamp is provided, it may be placed on the optical axis or on the periphery of the optical axis.

[0044] For example, the measurement light source 13 may consist of multiple measurement light sources, each of which may be arranged separately from one another in at least three meridian directions. Of course, the number of meridian directions in which the measurement light sources are arranged can be any number (for example, one meridian direction, two meridian directions, four meridian directions, etc.). In this embodiment, the case in which the measurement light sources are arranged in four meridian directions will be explained as an example. Furthermore, in this embodiment, the case in which the measurement light sources 13 are arranged sequentially on a virtual straight line extending in the meridian direction with respect to the optical axis center will be explained as an example.

[0045] In this embodiment, we will explain using as an example a configuration in which two sets of measurement light sources are symmetrically arranged with respect to the optical axis center O1 of the objective lens 26 in one meridian direction. Of course, a configuration in which the measurement light sources are not symmetrically arranged with respect to the optical axis center O1 of the objective lens 26 in one meridian direction is also possible. That is, a configuration in which the measurement light sources are arranged on only one side with respect to the optical axis center O1 of the objective lens 26 in one meridian direction is also possible. In this embodiment, for example, eight sets of measurement light sources (measurement light sources 13a, 13b, 13c, 13d, 13e, 13f, 13g, and 13h) are arranged in four meridian directions as the measurement light source 13.

[0046] For example, the eight sets of measuring light sources 13a to 13h are arranged concentrically at 45° intervals outside the outer circumference of the objective lens 26. Of course, the position of each measuring light source can be placed at any position. For example, measuring light source 13 is fixed to the base 14. Also, for example, the objective lens 26 is fixed to the base 14.

[0047] For example, the eight sets of measurement light sources 13a to 13h each have three measurement light sources. For example, the three light sources (for example, the three light sources 13a1, 13a2, and 13a3 in measurement light source 13a) are arranged sequentially at predetermined intervals in the meridian direction (radial direction) with respect to the optical axis center O1 of the objective lens 26. For example, each measurement light source can be controlled independently. For example, the illumination, light intensity adjustment, etc., of each measurement light source can be controlled independently.

[0048] In this embodiment, for example, the measurement light source 13 is configured to have eight sets of measurement light sources, but it is not limited to this. For example, the measurement light source 13 can have any number of sets of measurement light sources (e.g., three, four, five, six, etc.). In this embodiment, the eight sets of measurement light sources 13a to 13h are described using a configuration in which each has three measurement light sources as an example, but it is not limited to this. Each set of measurement light sources can have any number of measurement light sources (e.g., two, four, five, etc.).

[0049] For example, as described above, the measuring light source 13 is arranged concentrically outside the outer circumference of the objective lens 26.

[0050] For example, the detector 21 is conjugate to the pupil of the eye being examined. For example, the output from the detector 21 is input to the control unit 80. In this embodiment, for example, the optical axis L2 of the light-receiving optical system 20 and the optical axis L1 of the light-emitting optical system 10 are coaxial.

[0051] In the above configuration, the measurement light emitted from the measurement light source 13 is directed towards the eye E being examined. For example, the measurement light is irradiated onto the fundus of the eye E being examined through the presentation window 3. That is, the measurement light is irradiated onto the eye E being examined along the optical axis L1 of the light projection optical system 10. In this embodiment, the measurement light is irradiated onto both the left and right eyes being examined (left and right eyes).

[0052] For example, the measurement light irradiated onto the fundus of the eye under test E is reflected and scattered, exiting the eye under test E, and is focused by the objective lens 26. The reflected light focused by the objective lens 26 is detected by the detector 21. In this embodiment, the reflected light from each of the left and right eyes is detected by the detector 21.

[0053] In this embodiment, for example, the measurement light sources 13 are turned on sequentially. For example, the control unit 80 turns on the measurement light source 13a1. At this time, the other measurement light sources are kept off. For example, the measurement light emitted from the measurement light source 13a1 is irradiated onto the eye E under examination, and the reflected light reflected by the eye E under examination is detected by the detector 21. For example, when the control unit 80 obtains a detection result from the turning on of the measurement light source 13a1, it turns on the next measurement light source 13a2 and turns off the measurement light source 13a1, and obtains a detection result from the turning on of the measurement light source 13a2. For example, when the control unit 80 obtains a detection result from the turning on of the measurement light source 13a2, it turns on the next measurement light source 13a3 and turns off the measurement light source 13a2, and obtains a detection result from the turning on of the measurement light source 13a3.

[0054] For example, once the control unit 80 has obtained detection results from the three light sources of the measurement light source 13a, it performs measurements with the next set of measurement light sources. For example, the control unit 80 obtains detection results from the three light sources of the measurement light source 13b. In this case, the measurement light source 13b1 is turned on, and the other measurement light sources are turned off. Then, in the same manner as the measurement of the measurement light source 13a described above, the control unit 80 sequentially obtains detection results from each measurement light source. For example, once the control unit 80 has obtained detection results from the three light sources of the measurement light source 13a, it performs measurements with the next set of measurement light sources. For example, the control unit 80 sequentially performs measurements with each set of measurement light sources.

[0055] In this embodiment, the above-described configuration for illuminating the measurement light source was given as an example, but the embodiment is not limited to this. The order in which each measurement light source is illuminated can be any order.

[0056] <Photorefraction method> Next, for example, the photorefraction method will be described. Figure 3 is a diagram illustrating the photorefraction method. In this embodiment, for example, the control unit 80 detects reflected light from the fundus passing through the pupil using the detector 21, detects the ratio of the dimension of the bright crescent in the pupil in the pupillary radial direction to the pupillary diameter, and obtains the refractive power of the eye using the following formula 1 (see, for example, Japanese Patent Application Publication No. 2006-149501).

[0057]

number

[0058] Here, R represents the ratio of the dimension of the bright crescent K in the pupil to the pupil diameter (B / 2r). For example, B is the length of the bright crescent K in the pupillary radial direction. For example, r is the radius of the pupil of the eye being examined. For example, A is the refractive power of the eye being examined. For example, e is the distance from the end 26a of the objective lens 26 to the measurement light source 13 (in Figure 3, the measurement light source 13a1 in the measurement light source 13 is exemplified). For example, L is the reciprocal of the separation distance (measurement distance) S between the eye being examined E and the objective lens 26 (L = 1 / S).

[0059] As described above, for example, the proportion R of the bright crescent B will differ depending on the refractive power A of the eye being examined, assuming other conditions remain constant. That is, the refractive power A of the eye being examined can be calculated from the proportion R of the bright crescent measured under constant conditions using the following formula 2.

[0060]

number

[0061] As described above, the refractive power of the eye being examined is calculated using the photorefraction method.

[0062] In this embodiment, for example, the arrangement of the light-emitting optical system 10 and the light-receiving optical system 20 in Figure 1 can be any arrangement. For example, the light-emitting optical system 10 and the light-receiving optical system 20 may be placed in different positions and measurements may be performed on different optical axes.

[0063] <Department Head> For example, Figure 4 is a schematic diagram of the control system in the ophthalmic device 1. For example, the control unit 80 is connected to a display (monitor) 11, a measuring light source 13, a detector 21, a controller 81, a non-volatile memory 82, etc.

[0064] For example, the control unit 80 includes a CPU (processor), RAM, ROM, etc. For example, the CPU is responsible for controlling each component of the ophthalmic device 1. For example, RAM temporarily stores various types of information. For example, ROM stores various programs for controlling the operation of the ophthalmic device 1. Note that the control unit 80 may be composed of multiple control units (i.e., multiple processors).

[0065] For example, the controller 81 is used to switch the display on the display 11 or to perform measurements by illuminating the measurement light source 13. For example, a signal input from the controller 81 is input to the control unit 80 via a cable. In this embodiment, the signal from the controller 81 may also be input to the control unit 80 via wireless communication such as infrared. For example, at least one of the following may be used for the controller 81: a mouse, joystick, keyboard, touch panel, etc.

[0066] For example, in this embodiment, the controller 81 is provided in the housing 2. More specifically, the controller 81 is provided around the display 11. Of course, the controller 81 can be placed in any position, and may be provided in a configuration different from that of the housing 2.

[0067] For example, the display 11 may be a display mounted on the main body of the ophthalmic device 1, or a display connected to the main body of the ophthalmic device 1. A display of a personal computer (hereinafter referred to as "PC") may also be used. Multiple displays may be used in combination. The display 11 may also be a touch panel. When the display 11 is a touch panel, the display 11 functions as a controller. Images of the eye under examination, etc., are displayed on the display 11.

[0068] For example, non-volatile memory 82 is a non-transient storage medium that can retain its contents even when the power supply is cut off. For example, a hard disk drive, flash ROM, USB memory, etc., can be used as the non-volatile memory (hereinafter referred to as memory) 82. For example, a program for measurement processing is stored in memory 82.

[0069] <Control operation> The control operation of the ophthalmic device 1, which has the above configuration, will now be explained. In this embodiment, the explanation will be given using the ophthalmic device 1 as an example of a screening test performed on a child, such as a 3-year-old. For example, photorefraction measurement, such as that of the ophthalmic device 1, does not necessarily require strict alignment, and measurement results can be obtained simply and efficiently. For this reason, it is often used, in particular, for screening refractive errors (for example, myopia and hyperopia) in the eye being examined, especially for children who have difficulty maintaining fixation on the test target.

[0070] <Acquisition of objective refractive power of the eye under examination> For example, the examiner uses the ophthalmic device 1 to obtain the objective refractive power of the eye under examination. In this embodiment, measurements of both eyes are performed simultaneously. Of course, the measurements of the left and right eyes may be performed at different times. For example, the measurement of one eye may be completed before the measurement of the other eye begins.

[0071] For example, the examiner instructs the subject to observe the measurement light source 13 of the ophthalmic device 1. For example, the measurement light source 13 illuminates the anterior segment of the eye, including the subject's pupil, and the anterior segment image illuminated by the measurement light source 13 is detected by the detector 21. For example, the control unit 80 displays the anterior segment image detected by the detector 21 on the display 11. For example, the examiner adjusts the position of the ophthalmic device 1 so that the subject's left and right eyes are displayed on the display 11 of the ophthalmic device 1. For example, the control unit 80 may display on the display 11 that alignment is complete when the subject's left and right eyes are displayed on the display 11. Of course, the examiner may also recognize that alignment is complete by confirming that the subject's left and right eyes are displayed on the display 11 of the ophthalmic device 1.

[0072] For example, once alignment is complete, the examiner operates the controller 81 to select a switch to start the measurement. For example, the control unit 80 generates a measurement start trigger signal (hereinafter referred to as the trigger signal) to start the measurement based on the output of the operation signal from the controller 81. For example, when the trigger signal to start the measurement is generated, the control unit 80 emits measurement light from the measurement light source 13 of the light projection optical system 10. For example, the measurement light emitted from the measurement light source 13 is projected onto the fundus of the eye E being examined. In this embodiment, the measurement light is irradiated onto the fundus of both the left and right eyes. The reflected light of the measurement light reflected from the fundus is detected by the detector 21 of the light receiving optical system 20.

[0073] For example, the control unit 80 sequentially lights up each of the measurement light sources 13 and detects the reflected light from the eye under examination by the detector 21. For example, the output signal from the detector 21 is stored as image data (measurement image) in the memory 82. In this embodiment, image data for both the left and right eyes is acquired and stored in the memory 82. Subsequently, the control unit 80 analyzes the images stored in the memory 82 to determine the first refractive power values ​​of the left and right eyes.

[0074] This will be explained in more detail. For example, the control unit 80 calculates spherical information (spherical refractive power) in the direction in which the measuring light sources 13a are positioned, based on the detection results detected by the illumination of the measuring light sources 13a (three measuring light sources 13a1 to 13a3). For example, when calculating the spherical information in the direction in which the measuring light sources 13a are positioned, the control unit 80 acquires spherical information in the direction in which the measuring light sources 13a are positioned, based on at least one measurement result obtained from the illumination of the three measuring light sources 13a1 to 13a3. In this case, for example, the control unit 80 may acquire the average value of each spherical information obtained from each of the three measuring light sources 13a1 to 13a3 as the spherical information in the direction in which the measuring light sources 13a are positioned. Alternatively, in this case, for example, the control unit 80 may select one piece of spherical information from the three measuring light sources 13a1 to 13a3 and acquire it as the spherical information in the direction in which the measuring light sources 13a are positioned.

[0075] For example, once spherical information in the direction of arrangement of the measurement light source 13a is acquired as described above, the control unit 80 then acquires spherical information in each of the arrangement directions of the other measurement light sources 13b to 13h in the same manner as described above.

[0076] Figure 5 illustrates the illumination of the measurement light source 13. In Figure 5, among the measurement light source (multiple measurement light sources) 13, the measurement light source used in the normal measurement mode is shown with hatching (filled in). As described above, each measurement light source in the measurement light source 13 is illuminated sequentially, and as a result, all light sources in the measurement light source 13 are illuminated in sequence and measurements are performed (all measurement light sources are represented by the hatched areas).

[0077] In this embodiment, the refractive power obtained includes spherical refractive power, cylindrical refractive power, and astigmatism axis angle. For example, when spherical information is obtained for each direction, the control unit 80 obtains the spherical refractive power based on the spherical information for each direction. For example, the average value of the spherical refractive powers obtained for each direction may be used as the spherical refractive power. Of course, the spherical refractive power may be obtained based on at least one of the spherical refractive powers from each direction. Also, for example, the control unit 80 obtains the cylindrical refractive power and astigmatism axis angle based on the spherical refractive power (spherical refractive power distribution) in each direction. That is, for example, the control unit 80 obtains the refractive power of spherical refractive power (S), cylindrical refractive power (C), and astigmatism axis angle (A).

[0078] Here, for example, the refractive power of the eye under examination is obtained in two patterns: the first refractive power and the second refractive power. For example, the first refractive power may include the first spherical refractive power, the first cylindrical refractive power, and the first astigmatism axis angle. Also, for example, the second refractive power may include the second spherical refractive power, the second cylindrical refractive power, and the second astigmatism axis angle. For example, in the first refractive power, the first cylindrical refractive power is the cylindrical refractive power expressed with a positive sign (i.e., the cylindrical refractive power read as positive). Also, for example, the first spherical refractive power is the spherical refractive power corresponding to such a cylindrical refractive power expressed with a positive sign. Similarly, for example, in the second refractive power, the second cylindrical refractive power is the cylindrical refractive power expressed with a negative sign (i.e., the cylindrical refractive power read as negative). Furthermore, for example, the second spherical refractive power is the spherical refractive power that corresponds to the cylindrical refractive power expressed with a negative sign.

[0079] In this embodiment, the first and second refractive powers of the left eye, and the first and second refractive powers of the right eye are obtained. For example, for the left eye, the first refractive power is obtained as follows: first spherical refractive power -1.50D, first cylindrical refractive power +0.50D, and first astigmatism axis angle 180°. Also, the second refractive power is obtained as follows: second spherical refractive power -1.00D, second cylindrical refractive power -0.50D, and second astigmatism axis angle 90°. For example, for the right eye, the first refractive power is obtained as follows: first spherical refractive power -2.50D, first cylindrical refractive power +1.50D, and first astigmatism axis angle 180°. Furthermore, the second eye's refractive power is obtained as follows: second spherical refractive power -1.00D, second cylindrical refractive power -1.50D, and second astigmatism axis angle 90°. Note that for the left and right eyes, the first cylindrical refractive power is read as a positive value, and the second cylindrical refractive power is read as a negative value, so their signs are reversed. Also, depending on how the first and second cylindrical refractive powers are read, the corresponding first and second spherical refractive powers will take different values. For example, the first and second eye refractive powers for the left and right eyes are stored in memory 82.

[0080] <Selection of screening values> For example, when the control unit 80 obtains the first and second refractive powers of the eye under examination, it selects the spherical refractive power with the largest absolute value among the first spherical refractive power corresponding to the first cylindrical refractive power with a positive sign (read as positive) and the second spherical refractive power corresponding to the second cylindrical refractive power with a negative sign (read as negative), as a screening value for determining refractive errors in the eye under examination. More specifically, for example, the control unit 80 selects the spherical refractive power with the largest absolute value as the screening value by comparing the first and second spherical refractive powers.

[0081] First, let's explain the left eye. For example, the first spherical refractive power corresponding to a positive reading in the left eye is -1.50D, and the second spherical refractive power corresponding to a negative reading in the left eye is -1.00D. Therefore, for example, the control unit 80 calculates the absolute values ​​of the first spherical refractive power -1.50D and the second spherical refractive power -1.00D, and then compares these absolute values ​​to select the spherical refractive power with the larger absolute value as the screening value. For example, in this case, the second spherical refractive power corresponding to the negative reading is selected as the screening value.

[0082] Next, let's explain the right eye. For example, the first spherical refractive power corresponding to a positive reading for the right eye is -2.50D, and the second spherical refractive power corresponding to a negative reading for the right eye is -1.00D. Therefore, for example, the control unit 80 calculates the absolute values ​​of the first spherical refractive power -2.50D and the second spherical refractive power -1.00D, and then compares these absolute values ​​to select the spherical refractive power with the larger absolute value as the screening value. For example, in this case, the first spherical refractive power corresponding to a positive reading is selected as the screening value.

[0083] <Determination of refractive errors> For example, when the control unit 80 selects either a positive or negative spherical refractive power corresponding to the eye being examined as a screening value, it determines whether this screening value exceeds a predetermined threshold, which is the criterion for determining refractive errors in the eye being examined. For example, the control unit 80 determines whether the screening value exceeds a first threshold, which is the criterion for determining myopia, and whether it exceeds a second threshold, which is the criterion for determining hyperopia.

[0084] For example, in this embodiment, a first threshold and a second threshold for screening tests of infants are pre-set. For example, the first threshold for myopia is set to -2.00D. Also, for example, the second threshold for hyperopia is set to +2.00D. Therefore, for example, the control unit 80 determines that there is no refractive error in the eye if the screening value of the eye being examined falls within the acceptable range of -2.00D to +2.00D. Also, for example, the control unit 80 determines that there is a refractive error in the eye if the screening value of the eye being examined does not fall within the acceptable range of -2.00D to +2.00D.

[0085] Furthermore, if the control unit 80 determines that the eye under examination has a refractive error, it determines whether the screening value of the eye exceeds the first threshold or the second threshold. For example, if the screening value of the eye under examination has a negative sign, it determines that it exceeds the first threshold (-2.00D), which is set in the negative direction relative to 0.00D. For example, based on this, the control unit 80 determines that the eye under examination is suspected to be myopic. Also, if the screening value of the eye under examination has a positive sign, it determines that it exceeds the second threshold (+2.00D), which is set in the positive direction relative to 0.00D. For example, based on this, the control unit 80 determines that the eye under examination is suspected to be hyperopic. Note that the examiner may arbitrarily change the settings of these first and second thresholds. For example, the results of the refractive error determination by the control unit 80 are stored in the memory 82.

[0086] First, let's explain the left eye. For example, the screening value for the left eye is the first spherical refractive power of -1.50D, which corresponds to a negative reading. For example, the control unit 80 compares this screening value with a predetermined threshold (a tolerance range of ±2.00D). As an example, it may determine whether the screening value is below the upper limit of the tolerance range and above the lower limit of the tolerance range. For example, in this case, since the screening value for the left eye falls within the tolerance range, it is determined that there is no refractive error in the left eye.

[0087] Next, let's explain the right eye. For example, the screening value for the right eye is a first spherical refractive power of -2.50D, which corresponds to a positive reading. For example, the control unit 80 compares the screening value with a predetermined threshold (a tolerance range of ±2.00D), similar to the left eye. For example, in this case, the screening value for the right eye does not fall within the tolerance range, and it is determined that there is a refractive error in the right eye. Furthermore, since the screening value for the right eye has a negative sign, it is determined that it exceeds the first threshold (-2.00D), and the right eye is suspected of being myopic.

[0088] <Output of refractive power and screening results of the eye being examined> For example, the control unit 80 outputs the measurement result of the refractive power of the eye under examination obtained by the photorefraction method, and the screening result based on the determination result of refractive error in the eye under examination. For example, in this embodiment, the system is pre-set to output the second refractive power of the eye under examination, out of the first and second refractive powers, as the measurement result of the refractive power of the eye under examination. Therefore, for example, the measurement result of the refractive power of the eye under examination outputs the second cylindrical refractive power, which is represented by a negative sign, the second spherical refractive power corresponding to the second cylindrical refractive power, and the second astigmatism axis angle. Also, for example, in this embodiment, the measurement result of the refractive power of the eye under examination and the screening result are displayed on the display 11. For example, the screening result of the eye under examination is displayed as a message prompting further examination of the eye under examination.

[0089] Figure 6 shows an example of the display screen 100 of the display 11. Figure 6(a) is the initial screen displayed when the eye under examination is suspected of being myopic. Figure 6(b) is the screen when the display format of the refractive power measurement results is changed by operating the S.MAX display button 103, which will be described later. For example, the display screen 100 displays the screening result of the eye under examination 101, the refractive power measurement result of the eye under examination 102, the S.MAX display button 103, an alert mark 104, etc.

[0090] For example, screening result 101 is a message displayed based on the determination of refractive errors in the eye being examined. As an example, if there is a refractive error in at least one of the left or right eyes, "COMPLETE EYE EXAM RECOMMENDED" is displayed. As another example, if there is no refractive error in either the left or right eye, "SCREENING COMPLETE" is displayed. Note that the content of the message is not limited to these examples, and it should be something that allows the examiner to understand whether or not there is a refractive error in the eye being examined. In this example, the left eye was determined to have no refractive error, and the right eye was determined to be suspected of being myopic, so screening result 101 is "COMPLETE EYE EXAM RECOMMENDED".

[0091] For example, measurement result 102 is the measurement result of the refractive power of the eye being examined. For example, measurement result 102 displays the second refractive power, including the second cylindrical refractive power with a negative sign. In this embodiment, the second refractive power of the left eye is displayed as the second spherical refractive power of -1.00D, the second cylindrical refractive power of -0.50D, and the second astigmatism axis angle of 90°. In addition, the second refractive power of the right eye is displayed as the second spherical refractive power of -1.00D, the second cylindrical refractive power of -1.50D, and the second astigmatism axis angle of 90°.

[0092] For example, the S.MAX display button 103 is a button used to display the refractive power of the eye being examined as measurement result 102, which includes the spherical refractive power (first spherical refractive power or second spherical refractive power) with the largest absolute value among the first and second refractive powers. For example, by pressing the S.MAX display button 103, the refractive power including the spherical refractive power with the largest absolute value will be displayed as measurement result 102, regardless of the setting of the ophthalmic device 1 to display the second refractive power as the measurement result (in other words, regardless of the setting of the cylindrical refractive power symbol to be displayed preferentially).

[0093] The alert mark 104 indicates that the screening value used to determine the refractive error of the eye under examination (i.e., the first or second spherical refractive power with the largest absolute value) does not fall within a predetermined threshold. For example, in this embodiment, the alert mark 104 is displayed on the S.MAX display button 103 if the screening value of the eye under examination exceeds either the first threshold, which is the criterion for determining myopia, or the second threshold, which is the criterion for determining hyperopia. For example, the alert mark 104 may be displayed as an asterisk. Of course, the content of the alert mark is not limited to this, and it should contain information that allows the examiner to understand whether or not the eye under examination has a refractive error.

[0094] For example, in this embodiment, once the measurement of the refractive power of the eye under examination and the determination of refractive errors are completed, the control unit 80 displays the screen illustrated in Figure 6(a) on the display 11. For example, in this embodiment, the second refractive power corresponding to the negative reading of the eye under examination is displayed as the measurement result 102. However, the message in the screening result 101 is selected based on the absolute values ​​of the spherical refractive power (first spherical refractive power and second spherical refractive power) corresponding to both the negative and positive cylindrical refractive powers, making it extremely unlikely to miss a refractive error in the eye under examination. Therefore, for example, the examiner can easily determine whether or not there is a refractive error in the eye under examination by checking the message in the screening result 101.

[0095] For example, when the examiner checks the measurement results 102 to confirm the degree of refractive error in the eye being examined, whether the refractive error is in the left or right eye, etc., it may be difficult to grasp the details because neither the second spherical refractive power of the left eye (-1.00D) nor the second spherical refractive power of the right eye (-1.00D) exceeds the tolerance range of ±2.00D. Therefore, in this embodiment, the examiner can press the S.MAX display button 103 to switch the display of the measurement results 102 to a display of measurement results based on the spherical refractive power with the maximum absolute value.

[0096] For example, the control unit 80 may change the screen displayed on the display 11 from the screen exemplified in Figure 6(a) to the screen displayed in Figure 6(b) based on the operation signal from the S.MAX display button 103. For example, in the measurement result 102 of Figure 6(b), the first spherical refractive power of -2.50D, selected as the screening value, the first cylindrical refractive power of +1.50D corresponding to this first spherical refractive power, and the first astigmatic axis angle of 180° are displayed for the right eye. More specifically, for example, the measurement result 102 of Figure 6(b) switches from displaying the second eye refractive power corresponding to the negative reading to displaying the first eye refractive power corresponding to the positive reading. Also, an alert mark 104 is displayed for the first spherical refractive power. This allows the examiner to easily determine that the first spherical refractive power of the left eye, -1.50D, is within the acceptable range of ±2.00D, and that there is no refractive error in the left eye. Furthermore, the examiner can easily determine that the right eye has a refractive error (in this case, suspected myopia) because the first spherical refractive power of the right eye is -2.50D, which is outside the acceptable range of ±2.00D.

[0097] The above example shows the display screen 100 when there is no refractive error in the left eye of the eye being examined and myopia is suspected in the right eye. However, we will also explain the display screen 100 when there is no refractive error in either the left or right eye of the eye being examined. Figure 7 is an example of the display screen 100 when there is no refractive error in the eye being examined. Note that the screening results 101, measurement results 102, S.MAX display button 103, alert mark 104, etc. in Figure 7 are the same as those in the display screen 100 of Figure 6, so a detailed explanation will be omitted.

[0098] For example, once the control unit 80 has completed measuring the refractive power of the eye being examined and determining whether there is a refractive error, it displays the measurement results stored in the memory 82 and the screening results based on the refractive error determination on the display 11. For example, as a screening result for the eye being examined, since there is no refractive error in either the left or right eye, the message "SCREENING COMPLETE" is displayed. For example, the examiner can easily determine from the message of the screening result 101 that there is no refractive error in either the left or right eye.

[0099] As explained above, for example, the ophthalmic apparatus of this embodiment includes an acquisition means for acquiring at least spherical refractive power and cylindrical refractive power as the refractive power of the eye under examination, which acquires a first cylindrical refractive power with a positive sign and a first spherical refractive power corresponding to the first cylindrical refractive power, as well as a second cylindrical refractive power with a negative sign and a second spherical refractive power corresponding to the second cylindrical refractive power, a determination means for determining refractive errors based on the spherical refractive power with the maximum absolute value among the first and second spherical refractive powers and a predetermined threshold which is a criterion for determining refractive errors for the eye under examination, and a control means for outputting the determination result from the determination means. For example, the refractive power of the eye under examination can be expressed in two ways: a positive reading where the cylindrical refractive power is expressed with a positive sign, and a negative reading where the cylindrical refractive power is expressed with a negative sign. Depending on whether the cylindrical refractive power is read with a positive or negative sign, the spherical refractive power corresponding to the cylindrical refractive power changes. Therefore, for example, one method of reading cylindrical refractive power may result in spherical refractive power not exceeding the criterion for determining refractive error, while another method of reading cylindrical refractive power may result in spherical refractive power exceeding the criterion for determining refractive error. In such cases, for example, there is a possibility of missing a refractive error in the eye being examined, and the examiner cannot easily determine the refractive error. However, in this embodiment, for example, by using the spherical refractive power with the largest absolute value among the spherical refractive powers corresponding to each method of reading cylindrical refractive power to determine the refractive error, the refractive error can be easily determined. As a result, the chances of missing a refractive error in the eye being examined can be reduced.

[0100] Furthermore, for example, in the ophthalmic device of this embodiment, the control means outputs the refractive power of the eye under examination along with the determination result, and includes a setting means to set whether to output a first cylindrical refractive power with a positive sign or a second cylindrical refractive power with a negative sign as the cylindrical refractive power of the eye under examination. If the determination means determines that the spherical refractive power with the maximum absolute value is less than a predetermined threshold, the control means outputs the cylindrical refractive power with the sign set by the setting means and the spherical refractive power corresponding to the cylindrical refractive power with the sign set by the setting means as the refractive power. If the determination means determines that the spherical refractive power with the maximum absolute value is greater than or equal to a predetermined threshold, regardless of the sign set by the setting means, the control means outputs the spherical refractive power with the maximum absolute value and the cylindrical refractive power corresponding to the spherical refractive power with the maximum absolute value as the refractive power. For example, in an ophthalmic device, when outputting the refractive power of the eye under examination, it may be set to output the cylindrical refractive power as either a positive or negative reading. For example, in this case, since the cylindrical refractive power of the eye under examination is output using a reading based on the settings, it may be difficult to determine whether the spherical refractive power corresponding to this cylindrical refractive power exceeds the criteria for determining refractive errors. Therefore, for example, in this embodiment, if the spherical refractive power with the maximum absolute value among the positive and negative readings of the cylindrical refractive power exceeds the criteria, the refractive power of the eye under examination is output using the reading of the cylindrical refractive power that yields the spherical refractive power with the maximum absolute value. This makes it easier for the examiner to determine refractive errors in the eye under examination.

[0101] Furthermore, for example, the ophthalmic apparatus of this embodiment includes a measurement means for objectively measuring the refractive power of the eye under examination using a photorefraction method. The measurement means has a plurality of measurement light sources arranged in the meridian direction with respect to the optical axis center, and includes a light projection optical system that irradiates the fundus of the eye under examination with measurement light emitted from the plurality of measurement light sources, and a light receiving optical system that detects the reflected light of the measurement light reflected by the fundus of the eye under examination with a detector. The acquisition means acquires at least the spherical refractive power and cylindrical refractive power based on the measurement results from the measurement means. For example, measurement using the photorefraction method is sometimes used in screening tests for amblyopia in young children such as 3-year-olds. For example, amblyopia in young children is easily improved with early treatment, and early detection through screening tests is necessary. Therefore, even if an ophthalmic device measures using the photorefraction method, for example, by using the spherical refractive power with the maximum absolute value among the positive and negative readings of cylindrical refractive power to determine refractive errors, the possibility of missing refractive errors (in this case, especially amblyopia) in the examined eye can be reduced.

[0102] <Example of transformation> In this embodiment of the ophthalmic device, the refractive error of the eye under examination is determined by determining whether the screening value of the eye falls within the acceptable range from the first threshold to the second threshold. However, the invention is not limited to this. For example, the refractive error of the eye under examination may be determined by determining whether the screening value of the eye under examination exceeds the first threshold for myopia, or whether it exceeds the second threshold for hyperopia. For example, in this case, the determination of which threshold to exceed may be performed depending on whether the screening value of the eye under examination is negative or positive. For example, if the screening value of the eye under examination is negative, only the determination of whether it exceeds the first threshold for myopia may be performed. Also, for example, if the screening value of the eye under examination is positive, only the determination of whether it exceeds the second threshold for hyperopia may be performed. Of course, whether the screening value of the eye under examination is negative or positive, both the determination of whether it exceeds the first threshold and the determination of whether it exceeds the second threshold may be performed.

[0103] In this embodiment, the ophthalmic device is described as having a configuration that obtains a screening value for determining refractive errors in the eye under examination (i.e., the first or second spherical refractive power with the largest absolute value) by comparing the first spherical refractive power, which is expressed as a negative reading of the cylindrical refractive power, with the second spherical refractive power, which is expressed as a positive reading of the cylindrical refractive power, based on the refractive power of the eye under examination. However, the invention is not limited to this configuration. For example, either the first or second spherical refractive power may be obtained as a screening value based on the sign of the equivalent spherical refractive power of the eye under examination.

[0104] For example, if the equivalent spherical refractive power of the eye under examination is positive, the second spherical refractive power corresponding to the second cylindrical refractive power with a negative sign may be obtained as a screening value. Alternatively, for example, if the equivalent spherical refractive power of the eye under examination is negative, the first spherical refractive power corresponding to the first cylindrical refractive power with a positive sign may be obtained as a screening value.

[0105] For example, if the first eye's refractive power is obtained as follows: first spherical refractive power +1.00D, first cylindrical refractive power +1.50D, and first astigmatism axis angle 90°; and the second eye's refractive power is obtained as follows: second spherical refractive power +2.50D, first cylindrical refractive power -1.50D, and first astigmatism axis angle 180°, then the equivalent spherical refractive power (SE) is calculated to be +1.75D for both the first and second eye refractive powers. For example, since the equivalent spherical refractive power is positive, the control unit 80 may obtain the second spherical refractive power of +2.50D, which corresponds to the second cylindrical refractive power with a negative sign, as a screening value. For example, by changing the selection of the first and second spherical refractive powers according to the sign of the equivalent spherical refractive power, it is possible to obtain a spherical refractive power with the maximum absolute value.

[0106] In this embodiment of the ophthalmic device, an example configuration was described in which either the first spherical refractive power or the second spherical refractive power with the maximum absolute value is acquired as a screening value for determining refractive errors in the eye under examination, and refractive errors are determined based on whether or not this value exceeds a predetermined threshold. However, the device is not limited to this configuration. For example, a configuration may be used in which refractive errors are determined by comparing both the first spherical refractive power and the second spherical refractive power with a predetermined threshold. That is, both the first spherical refractive power and the second spherical refractive power may be used as screening values ​​for determining refractive errors. For example, in this case, the control unit 80 may compare both the first spherical refractive power and the second spherical refractive power with a predetermined threshold and determine that there is a refractive error if at least one of the first or second spherical refractive power exceeds the predetermined threshold.

[0107] In this embodiment, the ophthalmic device was described using a configuration that is pre-set to display the second eye refractive power, including the negative reading of the second cylindrical refractive power, in the measurement result 102 on the display screen 100 (see Figure 6), but it is not limited to this. For example, it may be pre-set to display the first eye refractive power, including the positive reading of the first cylindrical refractive power. Also, for example, it may be a configuration in which the examiner can arbitrarily change the setting to display either the first eye refractive power or the second eye refractive power.

[0108] In this embodiment, the ophthalmic device is described as having a configuration in which pressing the S.MAX display button 103 on the display screen 100 (see Figure 6) displays the refractive power including the spherical refractive power with the maximum absolute value (first spherical refractive power or second spherical refractive power) as the measurement result 102, but it is not limited to this. For example, the configuration may change whether to display the first or second refractive power of the eye examined as the measurement result 102 based on the determination result of the refractive error of the eye examined. For example, if the ophthalmic device 1 is set to display the second refractive power corresponding to a negative reading, the measurement result 102 may be displayed as the second refractive power if no refractive error is determined in the eye examined. When a refractive error is determined in the eye examined, the measurement result 102 may be displayed as the refractive power including the screening value used to determine the refractive error. Of course, both the first and second refractive power values ​​may be displayed in advance as the measurement result 102.

[0109] In this embodiment, the ophthalmic device is described as having a configuration that notifies the examiner of the presence or absence of a refractive error by displaying a message as a screening result 102 and an alert mark 104 when a refractive error is detected in the eye being examined. However, the device is not limited to this configuration. For example, instead of a message or an alert mark, the device may perform one of the following controls: color inversion or flashing of the spherical refractive power displayed in the measurement result 102, or display of a symbol other than an asterisk. Alternatively, the device may perform controls such as generating sound or vibration, or flashing a lamp, along with displaying a message or an alert mark.

[0110] In this embodiment, the ophthalmic device 1 is described as having a configuration in which refractive errors are determined by comparing the spherical refractive power with the maximum absolute value (here, the screening value) among the first spherical refractive power corresponding to the first cylindrical refractive power with a positive sign and the second spherical refractive power corresponding to the second cylindrical refractive power with a negative sign, with a predetermined threshold, and the refractive power of the eye under examination and the screening result are displayed on the display 11. However, the device is not limited to this configuration. For example, the ophthalmic device 1 may acquire the first spherical refractive power and the second spherical refractive power, and display the spherical refractive power with the maximum absolute value among them on the display 11. In other words, the configuration may not necessarily perform the comparison process between the screening value and the predetermined threshold for determining refractive errors in the eye under examination. Of course, for example, the ophthalmic device 1 may output the spherical refractive power with the maximum absolute value, along with the corresponding cylindrical refractive power, astigmatism axis angle, equivalent spherical refractive power, etc.

[0111] Furthermore, if, for example, a spherical refractive power with an absolute value that is not the maximum is displayed, the spherical refractive power with an absolute value that is not the maximum will not exceed the criteria for determining refractive errors, but the spherical refractive power with an absolute value that is the maximum may exceed the criteria for determining refractive errors, which could lead to missing refractive errors in the eye being examined. However, if, for example, the spherical refractive power with an absolute value that is the maximum is displayed, the spherical refractive power that is furthest from 0.00D is displayed in advance, so the examiner can easily determine whether or not it exceeds the criteria for determining refractive errors by checking the display 11. Therefore, even examiners with particularly little knowledge are less likely to miss refractive errors in the eye being examined.

[0112] Thus, for example, the ophthalmic apparatus of this embodiment includes an acquisition means for acquiring at least spherical refractive power and cylindrical refractive power as the refractive power of the eye under examination, which acquires a first cylindrical refractive power with a positive sign and a first spherical refractive power corresponding to the first cylindrical refractive power, as well as a second cylindrical refractive power with a negative sign and a second spherical refractive power corresponding to the second cylindrical refractive power, and a control means for outputting the refractive power of the eye under examination, which outputs the spherical refractive power with the maximum absolute value among the first and second spherical refractive powers. For example, by confirming the spherical refractive power with the maximum absolute value, the examiner can easily determine whether the eye under examination has a refractive error.

[0113] In this embodiment, the ophthalmic device 1 was described as a device that objectively measures the refractive power of the eye under examination using the photorefraction method, but it is not limited to this. For example, the ophthalmic device may be a device that objectively measures the refractive power of the eye under examination using a method other than the photorefraction method. Alternatively, for example, the ophthalmic device may be a subjective optometry device that subjectively measures the refractive power of the eye under examination.

[0114] For example, a subjective optometry device may have a corrective optical system positioned in the optical path of a projection optical system that projects a target beam toward the eye under examination, which changes the optical properties of the target beam, and may also include a subjective measuring means for subjectively measuring the optical properties of the eye under examination. As an example, the corrective optical system may be an optometry unit (phoropter) that switches and positions optical elements placed in front of the eye under examination. As another example, the corrective optical system may have an optical member for guiding the target beam toward the eye under examination, a target presentation unit for presenting the target to the eye under examination, and an optical element placed between them, and the optical properties of the target beam may be changed by controlling the optical element. In other words, the corrective optical system may be a phantom lens refractometer (phantom corrective optical system). [Explanation of Symbols]

[0115] 1 Ophthalmology equipment 2. Enclosure 3. Presentation window 10. Floodlight optics 11 displays 13 Measurement light source 14 Base 20 Light receiving optical system 21 Detectors 25. Optical system for light detection 26 Objective lens 40 Floodlight Optics 100 display screens

Claims

1. An ophthalmic device for objectively measuring the refractive power of the eye under examination, An acquisition means for acquiring at least spherical refractive power and cylindrical refractive power as the refractive power of the eye under examination, comprising: an acquisition means for acquiring a first cylindrical refractive power with a positive sign and a first spherical refractive power corresponding to the first cylindrical refractive power, and an acquisition means for acquiring a second cylindrical refractive power with a negative sign and a second spherical refractive power corresponding to the second cylindrical refractive power, A determination means for determining refractive errors based on the spherical refractive power having the maximum absolute value among the first and second spherical refractive powers, and a predetermined threshold which is a criterion for determining refractive errors in the eye being examined. A control means that outputs the determination result from the determination means, An ophthalmic device characterized by being equipped with the following features.

2. In the ophthalmic device according to claim 1, The control means outputs the refractive power of the eye under examination along with the determination result. The system includes a setting means for setting whether to output the first cylindrical refractive power with a positive sign or the second cylindrical refractive power with a negative sign as the cylindrical refractive power of the eye under examination, The control means is If the determination means determines that the spherical refractive power having the maximum absolute value is less than the predetermined threshold, the setting means outputs the cylindrical refractive power with the symbol set by the setting means and the spherical refractive power corresponding to the cylindrical refractive power with the symbol set by the setting means as the eye refractive power. An ophthalmic device characterized in that, when the determination means determines that the spherical refractive power having the maximum absolute value is equal to or greater than the predetermined threshold, the device outputs the spherical refractive power having the maximum absolute value and the cylindrical refractive power corresponding to the spherical refractive power having the maximum absolute value as the ocular refractive power, regardless of the sign set by the setting means.

3. In an ophthalmic device according to either claim 1 or 2, The system includes a measuring means for objectively measuring the refractive power of the eye under examination using a photorefraction method, The aforementioned measuring means is A light projection optical system having multiple measurement light sources arranged in the meridian direction with respect to the optical axis center, and irradiating the fundus of the eye under examination with measurement light emitted from the multiple measurement light sources, A light-receiving optical system that detects the reflected light of the measurement light reflected by the fundus of the eye being examined using a detector, It has, The acquisition means is characterized by acquiring at least the spherical refractive power and the cylindrical refractive power based on the measurement results from the measurement means.

4. An ophthalmic device for objectively measuring the refractive power of the eye under examination, An acquisition means for acquiring at least spherical refractive power and cylindrical refractive power as the refractive power of the eye under examination, comprising: an acquisition means for acquiring a first cylindrical refractive power with a positive sign and a first spherical refractive power corresponding to the first cylindrical refractive power, and an acquisition means for acquiring a second cylindrical refractive power with a negative sign and a second spherical refractive power corresponding to the second cylindrical refractive power, A control means for outputting the refractive power of the eye under examination, comprising a control means for outputting the spherical refractive power that has the maximum absolute value among the first spherical refractive power and the second spherical refractive power, An ophthalmic device characterized by being equipped with the following features.

5. It is an ophthalmology program, An acquisition step to obtain at least spherical refractive power and cylindrical refractive power as the refractive power of the eye under examination, comprising: an acquisition step to obtain a first cylindrical refractive power with a positive sign and a first spherical refractive power corresponding to the first cylindrical refractive power, and an acquisition step to obtain a second cylindrical refractive power with a negative sign and a second spherical refractive power corresponding to the second cylindrical refractive power, A determination step in which a refractive error is determined based on the spherical refractive power having the maximum absolute value among the first spherical refractive power and the second spherical refractive power, and a predetermined threshold which is a criterion for determining refractive errors in the eye being examined. A control step that outputs the determination result from the determination step, An ophthalmology program characterized by having a processor execute it.

6. It is an ophthalmology program, An acquisition step to obtain at least spherical refractive power and cylindrical refractive power as the refractive power of the eye under examination, comprising: an acquisition step to obtain a first cylindrical refractive power with a positive sign and a first spherical refractive power corresponding to the first cylindrical refractive power, and an acquisition step to obtain a second cylindrical refractive power with a negative sign and a second spherical refractive power corresponding to the second cylindrical refractive power, A control step for outputting the refractive power of the eye under examination, comprising: a control step for outputting the spherical refractive power that has the maximum absolute value among the first spherical refractive power and the second spherical refractive power; An ophthalmology program characterized by having a processor execute it.

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