ophthalmic devices

Abstract

To provide an ophthalmologic apparatus capable of measuring optical characteristics for an IOL implanted eye with an easy structure.SOLUTION: An ophthalmologic apparatus for objectively measuring optical characteristics of a subject's eye comprises: an eye refracting power measuring optical system for acquiring an eye refracting power of the subject's eye, which has a first projection optical system for projecting a first measuring light reflux to the fundus oculi of the subject's eye, and a first reception optical system for detecting, with a first detector, a first reflection light flux as a first indicator pattern image obtained by reflecting the first measuring light flux at the fundus oculi; and a contrast measuring optical system for acquiring contrast information relating to the contrast of the subject's eye, which has a second projection optical system for projecting a second measuring light reflux to the fundus oculi of the subject's eye, and a second reception optical system for detecting, with a second detector, a second indicator pattern image due to a second reflection light flux obtained by reflecting the second measuring light flux at the fundus oculi. The first detector and the second detector are different from each other.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to an ophthalmic device that objectively measures the optical characteristics of an eye to be examined.

Background Art

[0002] There is known an ophthalmic device that objectively measures the optical characteristics of an eye to be examined by projecting a measurement light beam toward the fundus of the eye to be examined and detecting the reflected light beam from the fundus. For example, in the wavefront aberration measurement device of Citation 1, a Hartmann plate is used to divide the reflected light beam into a plurality of light beams, and the wavefront aberration is measured based on the separation state of these images.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In recent years, an improvement in the measurement accuracy of the optical characteristics for an eye with an intraocular lens implanted has been demanded. However, in the wavefront aberration measurement device of Citation 1, due to differences in the characteristics of the intraocular lens, it is difficult to separate the images, and there are cases where accurate measurement results cannot be obtained. In addition, since the characteristics of the intraocular lens implanted in the eye to be examined are unknown, it is considered necessary to complicate the device configuration to determine this.

[0005] The present disclosure has been made in view of the above circumstances, and a technical problem thereof is to provide an ophthalmic device capable of measuring the optical characteristics of an eye with an intraocular lens implanted with a simple configuration.

Means for Solving the Problems

[0006] The ophthalmic device of this disclosure is an ophthalmic device for objectively measuring the optical properties of an eye under examination, comprising: a first light projection optical system that projects a first measurement light beam toward the fundus of the eye under examination; a first light receiving optical system that detects a first reflected light beam, which is the first measurement light beam reflected from the fundus, as a first indicator pattern image using a first detector; and a refractive power measuring optical system for acquiring the refractive power of the eye under examination, toward the fundus of the eye under examination. Periodically changing A second light projection optical system that projects a patterned second measurement light beam, and a second reflected light beam formed by the reflection of the second measurement light beam at the fundus of the eye. Periodically changing The system comprises a second light-receiving optical system that detects a second indicator pattern image using a second detector, and a contrast-measuring optical system for acquiring contrast information related to the contrast of the eye under examination, wherein the first detector and the second detector are Located in the conjugate position of the fundus It is characterized by having different detectors. [Brief explanation of the drawing]

[0007] [Figure 1] This is an external view of an ophthalmic device. [Figure 2] This is a schematic diagram of the optical system of an ophthalmic device. [Figure 3] This is a schematic diagram showing the reflected light beam from the fundus of the eye under examination and the pupil region. [Figure 4] This is an example of a patterned visual aid. [Figure 5] This is a schematic diagram of the control system for ophthalmic equipment. [Figure 6] This is an example of a pattern target image. [Figure 7] This is an example of information regarding the change in contrast value relative to the diopter information of the eye being examined. [Figure 8] This is an example of a graph corresponding to the eye being examined. [Figure 9] This is an example where the peak value appears at a distance different from the spherical frequency of 0D. [Figure 10] This is an example of a graph showing the relationship between the spherical power of the eye being examined and the peak contrast value P in each direction. [Modes for carrying out the invention]

[0008] <Overview> An overview of the ophthalmic apparatus according to the embodiments of this disclosure is described below. The items classified in < > below may be used independently or in relation to each other. In this embodiment, "conjugate" is not necessarily limited to a perfect conjugate relationship, but includes "approximately conjugate". That is, "conjugate" in this embodiment also includes cases where the parts are positioned away from the perfect conjugate position to the extent permitted in relation to the technical significance of each part.

[0009] The ophthalmic device of this embodiment is a device capable of objectively acquiring the optical properties of the eye under examination. For example, the ophthalmic device may have an optical system used for measuring the optical properties of the eye under examination. As an example, it may have an optical system used for measuring at least one of the following: aberration, refractive power (spherical power, cylindrical power, astigmatism axis angle, etc.).

[0010] For example, an ophthalmic device may have an optical system used to acquire contrast information of the eye under examination. For example, contrast information may be at least one of the following: a parameter indicating the contrast value, a parameter correlated with the contrast value, or a parameter that can be converted to a contrast value. For example, it may be the contrast value, the contrast sensitivity, the modulation transfer function (MTF), the point spread function (PSF), or the amount of blur. Contrast information may also be a combination of these pieces of information. Of course, it may also include information other than these.

[0011] Furthermore, the contrast information may have a directionality corresponding to the axis of the eye being examined (in other words, the astigmatism axis angle). In this case, one or more contrast information pieces corresponding to one or more astigmatism axis angles may be acquired.

[0012] <Optical refractive power measurement optical system> The ophthalmic apparatus of this embodiment may include an optical system for measuring ocular refractive power (for example, a first measuring optical system 100). The optical system for measuring ocular refractive power is an optical system for acquiring the refractive power of the eye under examination. For example, it may include a configuration for projecting a measurement light beam onto the fundus of the eye under examination and acquiring the refractive power based on the reflected light beam that is reflected from the fundus.

[0013] More specifically, the refractive power measurement optical system may include a first light projection optical system (e.g., projection optical system 110) that projects a first measurement light beam toward the fundus of the eye under examination, and a first light receiving optical system (e.g., light receiving optical system 120) that detects the first reflected light beam, which is the result of the first measurement light beam being reflected from the fundus, using a first detector. In the first light projection optical system, the first measurement light beam may be a visible light beam or an infrared light beam. The first light receiving optical system may detect the first reflected light beam as a first indicator pattern image using a first detector. Alternatively, the first light receiving optical system may detect the first reflected light beam that has passed through a pupil division region, in which the pupil region of the eye under examination is divided, as a first indicator pattern image using a first detector (e.g., image sensor 126).

[0014] The first light-receiving optical system may have a pattern optical element for focusing a first reflected light beam from the fundus of the eye as a pattern light beam onto the first detector. The pattern optical element causes a first index pattern image to be detected by the first detector. For example, the pattern optical element may be an optical element that can convert the first reflected light beam into any pattern light beam. As an example, the pattern optical element may be a screen with many holes (a so-called Hartmann plate). In this case, multiple point images are detected as the first index pattern image. As another example, the pattern optical element may be a ring optical element. In this case, a ring image is detected as the first index pattern image.

[0015] In this embodiment, the pattern optical member may be a ring optical member for condensing the first reflected light beam from the fundus oculi as a ring light beam onto the first detector. At least one ring image may be detected by the first detector as the first index pattern image by the ring optical member. For example, the ring optical member may be a ring lens. As an example, a ring lens having a ring aperture formed with one or a plurality of rings having different diameters and an annular lens portion corresponding to the ring aperture may be used. Further, instead of the ring lens, a condensing lens and a plurality of conical prisms arranged concentrically may be used.

[0016] The ophthalmic device of this embodiment may include a contrast measurement optical system (for example, the second measurement optical system 300). The contrast measurement optical system is an optical system for acquiring contrast information of the eye to be examined. For example, it may be configured to project a measurement light beam toward the fundus oculi of the eye to be examined and acquire contrast information based on the reflected light beam reflected by the measurement light beam at the fundus oculi.

[0017] More specifically, the contrast measurement optical system may include a second light projection optical system (for example, the light projection optical system 310) that projects a second measurement light beam toward the fundus oculi of the eye to be examined, and a second light reception optical system (for example, the light reception optical system 320) that detects the second reflected light beam reflected by the second measurement light beam at the fundus oculi by the second detector. In the second light projection optical system, the second measurement light beam may be a visible light beam or an infrared light beam. Further, the second light projection optical system may project a patterned second measurement light beam toward the fundus oculi of the eye to be examined. The second light reception optical system may detect a second index pattern image formed by the second reflected light beam reflected by the second measurement light beam by the second detector. Further, the second light reception optical system may detect a second index pattern image formed by the second reflected light beam passing through the pupil region of the eye to be examined by the second detector (for example, the imaging device 322).

[0018] <The First Measurement Light Beam and the Second Measurement Light Beam> In this embodiment, the first measurement beam of the refractive power measurement optical system may be an infrared beam having a wavelength in the infrared region. For example, the peak wavelength of the first measurement beam may be between 800 nm and 900 nm. This reduces the subject's perception of glare when the first measurement beam is projected, suppresses pupillary constriction, and allows for accurate determination of refractive power. However, if the eye E under test is an eye with an intraocular lens implanted, depending on the type of intraocular lens (e.g., monofocal intraocular lens, EDoF type intraocular lens, multifocal intraocular lens, etc.), it may not be possible to measure refractive power correctly. On the other hand, in this embodiment, the second measurement beam of the contrast measurement optical system may be a visible light beam having a wavelength in the visible region. For example, the peak wavelength of the second measurement beam may be between 400 nm and 800 nm. This allows for good acquisition of contrast information regardless of whether or not the eye has an intraocular lens implanted. Furthermore, even in the case of an eye with a diffractive intraocular lens implanted, if the light beam is visible, it can be appropriately distributed to both far and near distances according to the designed lens characteristics, thus allowing for the acquisition of contrast information.

[0019] In this embodiment, the first measurement beam of the refractive power measurement optical system may be a spot-shaped beam. In this case, the spot-shaped beam in the first light projection optical system may be detected by the first detector as a first index pattern image via the aforementioned pattern optical member. Alternatively, in this embodiment, the first measurement beam of the refractive power measurement optical system may be a pattern-shaped beam. For example, it may be a beam in the shape of at least one of the following patterns: a point cloud, a linear pattern, a radial pattern, etc. In this case, the pattern-shaped beam in the first light projection optical system may be detected by the first detector as a first index pattern image without going through the aforementioned pattern optical member.

[0020] In this embodiment, the second measurement beam of the contrast measurement optical system may be a spot-shaped beam. In this case, the spot-shaped beam in the second light projection optical system may be detected by the second detector. Also in this embodiment, the second measurement beam of the contrast measurement optical system may be a pattern-shaped beam. For example, it may be a beam in the shape of at least one of the following patterns: a point cloud, a linear pattern, a radial pattern, etc. It may also be a pattern-shaped beam that changes periodically, for example. As an example, it may be a beam in which the brightness alternately increases and decreases along at least one direction, or it may be a beam in which the brightness changes according to a sinusoidal function (using a so-called sinusoidal grating). In these cases, the pattern-shaped beam in the second light projection optical system may be detected by the second detector as a second index pattern image.

[0021] <Commonization of optical systems for measuring refractive power and contrast> In this embodiment, the refractive power measurement optical system and the contrast measurement optical system may share a common optical path. For example, at least a portion of the light emission path of the first measurement light beam in the first light emission optical system and the light emission path of the second measurement light beam in the second light emission optical system may be a common optical path. Alternatively, at least a portion of the light receiving optical path of the first reflected light beam in the first light receiving optical system and the light receiving optical path of the second reflected light beam in the second light receiving optical system may be a common optical path. Of course, both the commonization of each light emission optical path and the commonization of each light receiving optical path may be implemented.

[0022] For example, the first light source in the first light projection optical system and the second light source in the second light projection optical system may be the same (common) light source. Alternatively, for example, the first light source in the first light projection optical system and the second light source in the second light projection optical system may be different light sources. In other words, the light projection path of the first light source in the first light projection optical system and the light projection path of the second light source in the second light projection optical system may be coupled along the way to form a common light path.

[0023] For example, the first detector in the first light-receiving optical system and the second detector in the second light-receiving optical system may be the same (common) detector. Alternatively, for example, the first detector in the first light-receiving optical system and the second detector in the second light-receiving optical system may be different detectors. In other words, a common optical path shared between the light-receiving optical paths of the first and second light-receiving optical systems may be branched along the way and led to either the first or second detector. This allows for the acquisition of refractive power and contrast information of the eye under examination without complicating each optical system.

[0024] In this embodiment, the light-emitting optical path of the first light-emitting optical system and the light-receiving optical path of the first light-receiving optical system may be branched by a first optical path branching member. Also in this embodiment, the light-receiving optical path of the first light-receiving optical system and the light-receiving optical path of the second light-receiving optical system may be branched by a second optical path branching member. For example, the first optical path branching member and the second optical path branching member may be composed of at least one optical element such as a beam splitter, a dichroic mirror, or a half mirror. The second optical path branching member may be placed between the first optical path branching member and a pattern optical element, thereby positioning the first detector and the second detector on different optical paths.

[0025] Furthermore, if the second reflected light beam of the second light-receiving optical system is also configured to pass through a pattern optical element, as in the first light-receiving optical system (i.e., the first and second detectors are used together), the second index pattern image formed by the second reflected light beam is divided into multiple images by the pattern optical element. For example, if the pattern optical element is a Hartmann plate, the second index pattern image is separated according to the number of holes and detected by the detector as multiple images. If the pattern optical element is a ring optical element, the multiple images are detected by the detector as overlapping rings. This makes it difficult to acquire contrast information. However, by providing a first detector and a second detector separately, as in this embodiment, the second index pattern image can be detected as a single image, and contrast information can be appropriately acquired.

[0026] <First acquisition means> The ophthalmic apparatus of this embodiment may include a first acquisition means (for example, a control unit 80). The first acquisition means projects a first measurement light beam toward the fundus of the eye under examination and detects the reflected light beam, which is the first measurement light beam reflected from the fundus, with a first detector to acquire the optical characteristics of the eye under examination. For example, the refractive power of the eye under examination may be acquired by analyzing the detection result of the first detector by an optical system for measuring refractive power. The detection result of the first detector may be signal data or image data.

[0027] <Second acquisition means> The ophthalmic apparatus of this embodiment may also include a second acquisition means (for example, a control unit 80). The second acquisition means projects a second measuring light beam toward the fundus of the eye under examination and acquires contrast information of the eye under examination by detecting the reflected light beam, which is the second measuring light beam reflected from the fundus, using a second detector. For example, contrast information of the eye under examination may be acquired by analyzing the detection result of the second detector by a contrast measurement optical system. The detection result of the second detector may be signal data or image data.

[0028] The second acquisition means may acquire multiple contrast information sets, each with at least different diopter information, from the eye under examination. For example, the diopter information may be spherical power information, cylindrical power information, or astigmatism axis angle information. Of course, a combination of these information sets is also acceptable.

[0029] The second acquisition means may acquire multiple contrast information sets with different diopter information based on the presentation distance (presentation position) of the target presented to the eye under examination. In this case, the diopter information may be information obtained by replacing the presentation distance of the target presented to the eye under examination with diopter information. More specifically, the power (refractive index) of the eye under examination may be changed by changing the presentation distance of the target presented to the eye under examination, and the resulting change in the focal length of the eye under examination may be considered as a change in diopter information.

[0030] The second acquisition means may acquire multiple contrast information sets with different diopter information based on the optical characteristics of the eye examined acquired by the first acquisition means. In this case, the optical characteristics of the eye examined may be used as the diopter information of the eye examined.

[0031] The ophthalmic apparatus of this embodiment may also include a diopter information acquisition means (for example, a control unit 80). The diopter information acquisition means acquires diopter information. The second acquisition means may acquire a plurality of contrast information pieces in the eye under examination that have at least different diopter information, based on the diopter information acquired by the diopter information acquisition means.

[0032] For example, the diopter information acquisition means may acquire diopter information corresponding to the presentation distance of the visual target presented to the eye under examination. As an example, the diopter information acquisition means may acquire diopter information corresponding to each presentation distance when the visual target presented to the eye under examination is changed from a far distance to a near distance. In this case, the diopter information may be acquired by referring to a correspondence table that pre-associates the presentation distance of the visual target with the diopter information. Alternatively, in this case, the diopter information may be acquired by using a calculation formula to replace the presentation distance of the visual target with the diopter information.

[0033] For example, the diopter information acquisition means may acquire the diopter information of the eye under examination. As an example, the diopter information acquisition means may acquire the diopter information for each frequency when the optical characteristics added to the eye under examination are changed. In this case, the diopter information may be acquired using the first acquisition means. That is, the optical characteristics of the eye under examination acquired by the first acquisition means may be acquired as the diopter information of the eye under examination. In this case, the diopter information of the eye under examination may be acquired by storing the optical characteristics of the eye under examination in advance in a storage means (for example, memory 85) and retrieving them. In this case, the diopter information of the eye under examination may be acquired by receiving the optical characteristics of the eye under examination from another device (other control means).

[0034] The second acquisition means may project a patterned light beam as a second measurement light beam, detect a second index pattern image formed by the second reflected light beam, which is a second index pattern image that changes periodically, using a second detector, and acquire contrast information based on the luminance information in the second index pattern image. For example, contrast information may be acquired based on luminance information along the direction in which the second index pattern image changes periodically. If the second index pattern image has multiple directions in which it changes periodically, contrast information may be acquired based on multiple luminance information along each of these directions. For example, the luminance information may be information related to luminance. For example, it may be at least one of the following: the maximum luminance, the minimum luminance, the ratio of luminance tones, the luminance gradation, the luminance dispersion, etc. <Correction means> The ophthalmic apparatus of this embodiment may include a correction means (for example, a control unit 80). The correction means corrects the optical characteristics acquired by the first acquisition means based on the contrast information acquired by the second acquisition means. For example, the refractive power acquired by the first acquisition means may be corrected based on the contrast information acquired by the second acquisition means. For example, the optical characteristics may be corrected by detecting the amount of discrepancy in diopter information between the contrast information acquired by the second acquisition means and the optical characteristics acquired by the first acquisition means, and adding or subtracting the amount of discrepancy to the optical characteristics. This allows for improved accuracy of the measurement results by correcting the refractive power, even if, for example, the eye under examination is an eye with an intraocular lens implanted and the refractive power of the eye under examination is not properly acquired.

[0035] <Output method> The ophthalmic apparatus of this embodiment may include an output means (for example, a control unit 80). The output means outputs information on the change in contrast information relative to the diopter information. For example, the output means may output the change information by at least one of the following: output by displaying it on a display means (for example, a display unit 16), output by transmitting it to a memory or server, output by printing it to a printer, output by transferring it to an external device, etc. For example, by outputting the change information, it becomes easier to determine whether the eye under examination is an eye with an intraocular lens implanted, and if so, what kind of lens it is. It also becomes easier to determine whether the optical characteristics acquired by the first acquisition means are appropriate.

[0036] The change information may include a first data point indicating the peak value of the contrast information relative to the diopter information. For example, the first data point may be the peak value of the contrast information, i.e., the data point at the top of the peak. In this case, the data point at the top may be at least one of the maximum value and a value different from the maximum value.

[0037] The change information may include second data that shows peripheral values ​​relative to the first data. For example, the second data may include at least one contrast information value at a position where the diopter information is greater than that of the first data, relative to the diopter information of the first data. It may also include at least one contrast information value at a position where the diopter information is smaller than that of the first data, relative to the diopter information of the first data. Furthermore, it may include multiple contrast information values ​​at positions where the diopter information is greater and smaller than that of the first data, relative to the diopter information of the first data.

[0038] Furthermore, the change information may include both the first and second data, thereby representing at least a portion of the shape at the peak of the contrast information relative to the diopter information.

[0039] The output means may output change information so that a first data point showing the peak value of the contrast information relative to the diopter information and a second data point showing the peripheral values ​​relative to the first data point can be compared relatively. For example, the first data point and the second data point may be output superimposed. Alternatively, for example, the first data point and the second data point may be output in parallel. Alternatively, for example, the first data point and the second data point may be output in a switchable manner. Of course, a relative comparison of each data point may be made possible by combining these methods.

[0040] The output means may output a list as change information that associates diopter information with contrast information. For example, it may output a list that associates diopter information with multiple contrast information sets, including at least the first data set. Alternatively, for example, it may output a list that associates diopter information with multiple contrast information sets, including at least the first and second data sets.

[0041] The output means may output a graph of the distribution of contrast information relative to diopter information as change information. For example, a graph may be output in which multiple contrast information, including at least the first data, is plotted against the diopter information. Alternatively, for example, a graph may be output in which multiple contrast information, including at least the first and second data, is plotted against the diopter information. This allows for a visually clear representation of the contrast information of the eye under examination. It also makes it easy to understand how the contrast information of the eye under examination changes.

[0042] The output means may output a graph as change information that continuously shows the change in contrast information in response to a change in diopter information. In other words, it may output a graph that continuously shows the change in contrast information in response to a change in diopter information. For example, at least the first data may be included in such a continuous change in contrast information. Alternatively, at least the first data and the second data may be included. This makes it possible to grasp, for example, the positions of the far and near points of the eye under examination, the changes in diopter information before and after the far and near points, etc.

[0043] The output means may output both the optical characteristics of the eye under examination acquired by the first acquisition means and the contrast information of the eye under examination acquired by the second acquisition means. In this case, the optical characteristics of the eye under examination may be the values ​​acquired by the first acquisition means as they are. Alternatively, in this case, the optical characteristics of the eye under examination may be the values ​​corrected by the correction means. Alternatively, in this case, both the values ​​acquired by the first acquisition means and the values ​​corrected by the correction means may be output as the optical characteristics of the eye under examination.

[0044] The ophthalmic device of this embodiment shows the relationship between diopter information and contrast information for an eye with an intraocular lens implanted, enabling appropriate prescriptions that take into account the characteristics of the intraocular lens in the eye being examined. For example, when eyeglasses or other corrective lenses are needed for eye E, the amount of correction can be determined by considering this information. Furthermore, for example, when it is necessary to add or change an intraocular lens in the eye being examined, it becomes possible to select an appropriate lens.

[0045] It should be noted that the ophthalmic device of this embodiment is not limited to a configuration that acquires contrast information for eyes with intraocular lenses. Of course, it may also be configured to acquire contrast information for eyes without intraocular lenses. For example, even in eyes without intraocular lenses, the results of the optical characteristics obtained by the first acquisition means may not be appropriate due to differences in the pupil region of the eye being examined (for example, small pupil eyes). For this reason, errors in the optical characteristics may be detected by acquiring contrast information of the eye being examined.

[0046] <Examples> An embodiment of the ophthalmic device in this embodiment will be described.

[0047] <Overall Structure> Figure 1 is an external view of the ophthalmic device 10. The ophthalmic device 10 in this embodiment is an objective type refractive power measuring device. Here, an autorefractometer is used as an example. Although the ophthalmic device 10 is a stationary type, it is not necessarily limited to this and may also be a handheld type.

[0048] The ophthalmic device 10 includes at least a base 11, a measuring unit 12, an alignment drive unit 13, a face support unit 15, a display unit 16, an operating unit 17, and a control unit 80, etc.

[0049] The measurement unit 12 houses the optical system and other components used for measuring the eye under examination. The alignment drive unit 13 allows the measurement unit 12 to move three-dimensionally relative to the base 11. The face support unit 15 is fixed to the base 11 and supports the face of the person under examination. The display unit 16 functions as a touch panel that also serves as an operation unit. The display unit 16 also displays the refractive power, anterior segment cross-sectional image, axial length, etc., of the eye under examination E on the screen. The display unit 16 displays various information (for example, anterior segment image of the eye under examination, measurement results of the eye under examination, etc.). The operation unit 17 is used for various settings. Note that the display unit 16 functions as a touch panel, and the display unit 16 may also serve as the operation unit 17.

[0050] <Optical system> Figure 2 is a schematic diagram of the optical system of the ophthalmic device 10. As an example, the measurement unit 12 includes a first measurement optical system 100, a second measurement optical system 300, a fixation target presentation optical system 150, an observation optical system 200, an index projection optical system 400, an alignment index projection optical system 600, etc. It also includes half mirrors 501 and 502, an objective lens 505, etc., which branch and combine the optical paths of each optical system.

[0051] <1st measurement optical system> The first measuring optical system 100 is used to objectively measure the refractive power of the eye E under examination. The first measuring optical system 100 includes a projection optical system 110 and a light-receiving optical system 120. The projection optical system 110 projects a spot-shaped measuring light beam onto the fundus of the eye E under examination through the center of the pupil. The light-receiving optical system 120 extracts the reflected light beam of the measuring light beam reflected by the fundus in a ring shape through the periphery of the pupil.

[0052] The projection optical system 110 includes a light source 111, a relay lens 112, a hall mirror 113, a prism 115, an objective lens 505, etc. The light source 111 is positioned on the optical axis L1 and at the conjugate position of the fundus. The light source 111 may be an SLD (Superluminescent diode) light source, an LED (Light Emitting Diode) light source, or any other light source. In this embodiment, the light source 111 is an infrared light source, and an infrared luminous beam may be projected as the measurement luminous beam. For example, it may be a near-infrared luminous beam with a peak between wavelengths of 800 nm and 900 nm. As an example, it may be a near-infrared luminous beam with a peak at a wavelength of 870 nm. The aperture of the hall mirror 113 is positioned at the conjugate position of the pupil. The prism 115 is positioned away from the conjugate position of the pupil, and the measurement luminous beam passing through the prism 115 is eccentric with respect to the optical axis L1. Alternatively, a parallel plane plate may be positioned diagonally with respect to the optical axis L1 instead of the prism 115.

[0053] The light-receiving optical system 120 includes an objective lens 505, a prism 115, a hall mirror 113, relay lenses 121 and 122, a light-receiving diaphragm 123, a collimator lens 124, a ring lens 125, an image sensor 126, etc. The light-receiving diaphragm 123 is positioned at the conjugate position of the fundus. The ring lens 125 is positioned at the conjugate position of the pupil. The image sensor 126 is positioned at the conjugate position of the fundus.

[0054] The measurement light beam from the light source 111 passes through the relay lens 112, the hole portion of the hole mirror 113, and the prism 115, is reflected by the half mirrors 502 and 501 respectively, and then reaches the fundus of the eye via the objective lens 505. The reflected light beam, which is reflected from the measurement light beam at the fundus of the eye, travels along the optical path through which the measurement light beam passed, is reflected by the mirror portion of the hole mirror 113, travels in the direction of the optical axis L2, and reaches the image sensor 126 via the relay lenses 121 and 122, the light-receiving aperture 123, the collimator lens 124, and the ring lens 125.

[0055] In this embodiment, a prism 115 is placed on the common optical path of the projection optical system 110 and the light-receiving optical system 120. By rotating the prism 115 around the optical axis, the measurement light beam is rapidly eccentrically rotated over the pupil. For example, in this embodiment, the measurement light beam is eccentrically rotated in a region of φ2 mm to φ4 mm over the pupil. This region becomes the measurement region for refractive power (i.e., the pupil region).

[0056] The control unit 80, described later, analyzes the ring image formed on the image sensor 126 and derives the refractive power of the eye E under examination. For example, it performs analysis on the output image from the image sensor 126, or on the sum of the data output sequentially from the image sensor 126, to derive the refractive power. For example, the values ​​of spherical power, prismatic power, and astigmatism axis angle may be obtained.

[0057] The first measurement optical system 100 is not limited to the above configuration and may include a light projection optical system that projects a measurement light beam onto the fundus of the eye E under examination, and a light receiving optical system that receives the reflected light beam of the measurement light beam reflected by the fundus. For example, the first measurement optical system 100 may be an optical system that projects a spot indicator onto the fundus and detects the reflected light beam of the spot indicator in the fundus using a Shack-Hartmann sensor. In this case, a Hartmann plate may be used instead of the ring lens 125. The reflected light beam of the spot indicator is separated into multiple light beams by the Hartmann plate, and multiple point images are detected when the multiple light beams are imaged by the image sensor 126.

[0058] <Second measurement optical system> The second measuring optical system 300 is used to acquire contrast information of the eye E under examination. The second measuring optical system 300 includes a projection optical system 310 and a light-receiving optical system 320. The projection optical system 310 projects a patterned measuring light beam onto the fundus of the eye E under examination. The light-receiving optical system 120 receives the reflected light beam of the measuring light beam reflected by the fundus.

[0059] The projection optical system 310 includes a light source 311, a lens 312, a pattern target plate 313, a relay lens 112, a hall mirror 113, a prism 115, an objective lens 505, etc. The light source 311 is positioned on the optical axis L3 and at the conjugate position of the fundus. The light source 311 may be an SLD light source, an LED light source, a light source different from the SLD and LED, etc. In this embodiment, the light source 311 is a visible light source, and a visible light beam may be projected as the measurement light beam. For example, it may be a visible light beam with a peak between wavelengths of 500 nm and 580 nm. As an example, it may be a visible light beam with a peak at a wavelength of 550 nm. The pattern target plate 313 is positioned at the conjugate position of the fundus. Details of the pattern target plate 313 will be described later.

[0060] The light-receiving optical system 320 includes an objective lens 505, a prism 115, a hall mirror 113, relay lenses 121 and 122, a light-receiving diaphragm 123, a collimator lens 124, a lens 321, an image sensor 322, and the like. The image sensor 322 is positioned at the conjugate position in the fundus.

[0061] In this embodiment, the light source 111 of the projection optical system 110 is positioned on the transmission side of the half mirror 503, and the light source 311, lens 312, and pattern target plate 313 of the projection optical system 310 are positioned on the reflection side of the half mirror 503, so that the optical axes L1 and L3 coincide and their respective optical paths are made common. In addition, in this embodiment, the ring lens 125 and image sensor 126 of the light-receiving optical system 120 are positioned on the transmission side of the beam splitter 504, and the lens 321 and image sensor 322 of the light-receiving optical system 320 are positioned on the reflection side of the beam splitter 504, so that their respective optical paths are branched and the optical axes L2 and L4 no longer coincide.

[0062] In this embodiment, a beam splitter 504 is positioned on the optical axis L2 (on the optical path) between the hall mirror 113, which branches the optical axis L1 (optical path) of the projection optical system 110 and the optical axis L2 (optical path) of the light-receiving optical system 120, and the ring lens 125 of the projection optical system 110.

[0063] The measurement light beam from the light source 311 passes through the lens 312 and the pattern target plate 313, is reflected by the half mirror 503, and then passes sequentially through the relay lens 112 to the objective lens 505 before reaching the fundus of the eye. The reflected light beam, which is the measurement light beam reflected from the fundus of the eye, is reflected by the mirror portion of the hall mirror 113 via the optical path through which the measurement light beam passed, passes sequentially through the relay lens 121 to the collimator lens 124, is further reflected by the beam splitter 504, and then reaches the image sensor 322 via the lens 321.

[0064] In this embodiment, the measurement luminous flux from the light source 311 is eccentrically rotated by the prism 115, and contrast information is measured in a measurement area (pupil region) of φ2mm to φ4mm above the pupil.

[0065] The control unit 80, described later, acquires contrast information of the eye under examination E by analyzing the pattern image formed on the image sensor 322. For example, it performs analysis on the output image from the image sensor 126, or the summation image of the data sequentially output from the image sensor 126, to acquire contrast information. For example, the contrast information may be a contrast value. <Image formation from the first and second measurement optical systems> Figure 3 is a schematic diagram showing the reflected light beam from the fundus of the eye E under examination and the pupil region. Figure 3(a) shows the case of the first measurement optical system 100. Figure 3(b) shows the case of the second measurement optical system 300. Note that the ring lens 125 of the first measurement optical system 100 and the lens 321 of the second measurement optical system 300 are positioned at the pupil conjugate position and can be considered to be positioned on the pupil of the eye E under examination. In the first measurement optical system 100, the reflected light beam from the fundus is directed towards the pupil region 380, but the light beam that has passed through a part of the pupil region 380 (i.e., the pupil division region 390 obtained by dividing the pupil region 380) is extracted by the ring lens 125 and imaged as a ring image on the image sensor 126. On the other hand, in the second measurement optical system 300, the reflected light beam from the fundus is directed towards the pupil region 380, and the light beam that has passed through the entire pupil region 380 is extracted by the lens 321 and imaged as a pattern target image on the image sensor 322. For example, in this manner, the second measurement optical system 300 acquires a pattern target image by using the entire pupil area 380 of the eye E under examination (in other words, the effective diameter of the eye E under examination) in relation to the first measurement optical system 100.

[0066] <Fixation target presentation optical system> The fixation target presentation optical system 150 presents the fixation target to the eye E under examination. The fixation target presentation optical system 150 is used to make the eye E under examination fixate. It is also used to impart fogging and accommodative loading to the eye E under examination.

[0067] The fixation target presentation optical system 150 includes a light source 151, a fixation target plate 155, lenses 156 and 157, an objective lens 505, etc. The light source 151 is positioned on the optical axis L5. The fixation target plate 155 is positioned at the conjugate position of the fundus. The fixation beam from the light source 151 passes through the fixation target plate 155, lenses 156 and 157, then passes through the half mirror 502 to become coaxial with the optical axis L1, is reflected by the half mirror 501, and then reaches the fundus via the objective lens 505.

[0068] In this embodiment, the light source 111, ring lens 125, and image sensor 126 in the first measurement optical system 100, the light source 311, lens 312, pattern target plate 313, lens 321, and image sensor 322 in the second measurement optical system 300, and the light source 151 and fixation target plate 155 in the fixation target presentation optical system 150 can be moved integrally along the optical axis as a drive unit 160. For example, by moving the drive unit 160 by the drive unit 161 according to the refractive power of the eye under examination E, the presentation distance of the fixation target plate 155 relative to the eye under examination E (i.e., the presentation position of the fixation target) can be changed. Similarly, by moving the drive unit 160, the presentation distance of the pattern target plate 313 relative to the eye under examination E (i.e., the presentation position of the pattern target) can be changed.

[0069] Furthermore, the light source 111, ring lens 125, and image sensor 126 in the first measurement optical system 100, and the light source 311, lens 312, pattern target plate 313, lens 321, and image sensor 322 in the second measurement optical system 300 may be moved as a single drive unit, or the light source 151 and fixation target plate 155 in the fixation target presentation optical system 150 may be moved as a single drive unit. In other words, the first measurement optical system 100 and the second measurement optical system 300 and the fixation target presentation optical system 150 may each be provided as independent drive units.

[0070] Furthermore, the light source 111 in the first measurement optical system 100 and the light source 311 to the pattern target plate 313 in the second measurement optical system 300 may be treated as a single drive unit, and the ring lens 125 and image sensor 126 in the first measurement optical system 100 and the lens 321 and image sensor 322 in the second measurement optical system 300 may be treated as a single drive unit. In other words, the projection optical systems of the first measurement optical system 100 and the second measurement optical system 300, the light-receiving optical systems of the first measurement optical system 100 and the second measurement optical system 300, and the fixation target presentation optical system 150 may each be provided as independent drive units.

[0071] <Observation Optical System> The observation optical system 200 is used to capture an observation image of the anterior segment of the eye E under examination. The observation image is used for alignment, etc. For example, the observation optical system 200 includes an image sensor 201, a lens 202, an objective lens 505, etc. The image sensor 205 is positioned at the pupil conjugate position. The observation optical system 200 also serves as a detection optical system for detecting the index image projected onto the cornea from the index projection optical system 400 and the index image projected onto the cornea from the alignment index projection optical system 600.

[0072] <Indicator projection optical system> The index projection optical system 400 is used to measure the corneal shape. The index projection optical system 400 projects an index for measuring the corneal shape from the front facing the eye under examination to the anterior segment. The index projection optical system 400 is equipped with multiple point light sources 401. The point light sources 401 project an infinity index onto the cornea by irradiating it with parallel beams of light. The point light sources 401 are arranged symmetrically vertically and horizontally with respect to the optical axis L1. For example, in this embodiment, two point light sources are provided on each side. This projects four point image indexes onto the cornea. The number of indexes is not limited to this, and may consist of three or more point image indexes. Also, the shape of the indexes is not limited to this, and may include linear indexes, etc.

[0073] <Alignment indicator projection optics> The alignment indicator projection optical system 600 is used to align (position) the measurement unit 12 with respect to the eye E under examination. The alignment indicator projection optical system 600 is equipped with an alignment light source 601. The alignment light source 601 projects a finite distance indicator onto the cornea by irradiating it with a diffuse light beam. The alignment light source 601 is arranged in a ring shape with the optical axis L1 as the center. This projects a ring indicator (a so-called Mayer ring image) onto the cornea.

[0074] In this embodiment, an alignment index projection optical system is formed by an alignment light source 601 and an index projection optical system 400. For example, the working distance may be adjusted by moving the measuring unit 12 in the front-rear direction so that the Purkinje image from the alignment light source 601 and the Purkinje image from the index projection optical system 400 are captured at a predetermined ratio.

[0075] <Pattern visual target board> Figure 4 shows an example of a patterned target board 313. The patterned target board 313 is composed of a striped pattern in which the brightness changes along at least one direction. For example, it may be a striped pattern in which the brightness alternately increases and decreases. Alternatively, for example, it may be a striped pattern using a so-called sinusoidal grid in which the brightness changes according to a sinusoidal function. In this case, if the frequency in the sinusoidal function is high, the spacing between the stripes will be narrow, and if the frequency is low, the spacing between the stripes will be wide. The frequency may be set to a fixed value in advance, or it may be changed to an arbitrary value.

[0076] In this embodiment, the patterned target board 313 has patterns in four directions: pattern 313A which changes periodically along the vertical direction (90-degree direction), pattern 313B which changes periodically along the horizontal direction (180-degree direction), and patterns 313C and 313D which change periodically along the diagonal directions (45-degree and 135-degree directions). However, the patterned target board 313 may have patterns in at least one of these four directions. That is, it may have only pattern 313A, only pattern 313B, only pattern 313C, only pattern 313D, or a combination of multiple patterns. Of course, the patterned target board 313 may also have Landolt rings, letters, numbers, etc., in addition to striped patterns such as patterns 313A to 313D.

[0077] <Control System> Figure 5 is a schematic diagram of the control system of the ophthalmic device 10. The control unit 80 includes a CPU (processor), RAM, ROM, etc. The CPU controls the operation of each part of the ophthalmic device 10. The RAM temporarily stores various types of information. The ROM stores various programs executed by the CPU. Note that the control unit may be composed of multiple control units (i.e., multiple processors).

[0078] The control unit 80 is electrically connected to the alignment drive unit 13, display unit 16, operation unit 17, non-volatile memory 85 (hereinafter referred to as memory 85), etc. The control unit 80 is also electrically connected to the light sources, image sensors, drive units, etc. of the measurement unit 12. Memory 85 is a non-transient storage medium that can retain its contents even when the power supply is interrupted. For example, a hard disk drive, flash ROM, USB memory, etc., can be used as memory 85. The memory 85 may store the measurement results of the eye under examination E, etc.

[0079] <Control operation> The control operation of the ophthalmic device 10 will now be explained. In this embodiment, the ophthalmic device 10 sequentially acquires the refractive power and contrast information of the eye E being examined.

[0080] <Alignment> The examiner guides the subject to the ophthalmic device 10 and instructs them to place their face on the face support unit 15, and selects a button to start measuring the refractive power of the subject's eye E. Based on the control signal from the operation unit 17, the control unit 80 performs alignment of the measurement unit 12 with respect to the subject's eye E.

[0081] For example, the control unit 80 turns on the light source 151 of the fixation target presentation optical system 150 and presents the fixation target to the eye E under examination. It also turns on the light sources of the index projection optical system 400 and the alignment index projection optical system 600 and projects the alignment index onto the cornea of ​​the eye E under examination. For example, the control unit 80 detects the alignment index image (point image and Mayerring image) from the observation image captured by the image sensor 201 of the observation optical system 200, determines the X, Y, and Z displacement of the measurement unit 12 relative to the eye E under examination based on the alignment index image, and moves the measurement unit 12. This completes the alignment.

[0082] <Acquisition of refractive power> Once the alignment between the eye E and the measurement unit 12 is complete, the refractive power of the eye E is measured. For example, in measuring refractive power, a preliminary measurement may be performed first, followed by the main measurement.

[0083] In the preliminary measurement of the eye under test E, the refractive power of the eye is measured with the fixation target positioned at a predetermined presentation distance. For example, the control unit 80 positions the fixation target plate 155 at an initial position that is optically far enough from the eye under test E and corresponds to the far point of the 0D eye. The control unit 80 also irradiates the eye with a measurement beam from the light source 111 of the projection optical system 110 and performs image analysis on the ring image captured by the image sensor 126 of the light receiving optical system 120. For example, the control unit 80 thins the ring image to determine the refractive power in each meridian direction, performs a predetermined process on this refractive power, and obtains at least the spherical power (spherical power in the preliminary measurement).

[0084] Next, clouding is applied to the eye under test E. For example, the control unit 80 positions the fixation target 155 at the clouding start position where the eye under test E is in focus, according to the spherical power of the eye under test E measured in the preliminary test. The eye under test E can then clearly observe the fixation target. Subsequently, the control unit 80 moves the fixation target away from the clouding start position. The focus of the eye under test E is no longer on the fixation target, and clouding is applied. As a result, the accommodation of the eye under test E is released, and the refractive power approaches its true value.

[0085] In the main measurement of the eye under test E, the refractive power is measured with the eye under test E subjected to a cloud-like haze. For example, the control unit 80 causes the image sensor 226 to continuously capture ring images at predetermined intervals. In addition, for example, the control unit 80 reduces noise light by summing the ring images and acquires the refractive power (spherical power, cylindrical power, and astigmatism axis angle in the main measurement) in the same manner as in the preliminary measurement, and stores it in the memory 75.

[0086] Here, the eye E under examination may be an eye without an intraocular lens (IOL) implanted, or it may be an eye with an IOL implanted. If eye E is an eye with an IOL implanted, the refractive power may not be measured correctly depending on the type of IOL (e.g., monofocal IOL, EDoF type IOL, multifocal IOL, etc.). For example, with EDoF type IOLs and multifocal IOLs, the measurement results can easily be inaccurate depending on whether they are refractive or diffractive. However, the examiner does not always know whether eye E is an eye with an IOL implanted or not. Furthermore, even if the examiner knows that eye E is an eye with an IOL implanted, they may not know the type of IOL. For this reason, it is difficult for the examiner to judge whether the measurement result of the refractive power of eye E is appropriate.

[0087] In this embodiment, by acquiring contrast information (here, contrast value) of the eye E under examination, it becomes possible to distinguish whether or not the eye E has had an intraocular lens implanted. Furthermore, it becomes possible to infer the type of intraocular lens. In addition, it becomes possible to provide an appropriate prescription for eyes that have had an intraocular lens implanted.

[0088] <Acquiring contrast information> Once the refractive power of eye E is obtained, the contrast value of eye E is measured. For example, by changing the diopter information of eye E (for example, information on at least one of spherical power, cylindrical power, and astigmatism axis angle), multiple contrast values ​​with different diopter information may be measured. Here, we illustrate the case where the spherical power of eye E is continuously changed and the continuous change in the contrast value that accompanies this is measured.

[0089] The contrast value of the eye under test E is measured with the pattern target plate 313 positioned at a predetermined presentation distance, based on the refractive power of the eye under test E. For example, the distance at which the spherical power of the eye under test E becomes 0D may be set as the predetermined presentation distance of the pattern target plate 313. The control unit 80 drives the drive unit 161 and moves the drive unit 160 to position D1 corresponding to 0D (i.e., the contrast value measurement start position D1). Subsequently, the control unit 80 changes the spherical power added to the eye under test E. For example, by gradually moving the pattern target plate 313 from the measurement start position D1, the spherical power is changed from 0D to a negative value. The control unit 80 also stops the movement of the pattern target plate 313 when it reaches a predetermined presentation distance (i.e., the contrast value measurement end position D2). The measurement end position D2 may be set in advance or can be set arbitrarily. At this time, the fixation target plate 155 moves simultaneously with the pattern target plate 313, so initially the fixation target is also positioned at the 0D position, and the focus of the eye E under examination is on the fixation target. As the fixation target moves away from the position corresponding to 0D, the focus gradually shifts away from the fixation target.

[0090] The control unit 80 illuminates the pattern target plate 313 with a measurement beam from the light source 311 of the projection optical system 310 while the pattern target plate 313 moves from the measurement start position D1 to the measurement end position D2, and captures a pattern target image with the image sensor 322 of the light receiving optical system 320. For example, the pattern target image may be captured each time the spherical degree changes by one step (for example, 0.25D). Of course, the interval of one step is not limited to this, and may be smaller than 0.25D or larger than 0.25D. The pattern target image is stored in the memory 85 in association with the position of the pattern target plate 313 (i.e., the presentation distance of the pattern target).

[0091] Figure 6 shows an example of a pattern target image 500. The pattern target image 500 consists of pattern image 512A, which is the image of pattern 313A; pattern image 512B, which is the image of pattern 313B; pattern image 512C, which is the image of pattern 313C; and pattern image 512D, which is the image of pattern 313D. Each pattern image is captured as a single image on the image sensor 322. The control unit 80 thins the pattern target image 500 and acquires brightness information along the direction in which each pattern changes periodically. For example, for pattern image 512A, which changes periodically along the vertical direction, brightness information in the vertical direction is acquired. As an example, the maximum value Imax and minimum value Imin of brightness at at least one pixel line 550 in the vertical direction are calculated, and the contrast value K = (Imax - Imin) / (Imax + Imin) is determined to measure the contrast value Ka in the vertical direction. The width of the pixel line 550 may be 1 pixel width or 2 pixels or more. Furthermore, the number of pixel lines 550 may be two or more, and if multiple lines are provided, their average may be used as the contrast value.

[0092] Similarly, the control unit 80 calculates the maximum luminance Imax and minimum luminance Imin as lateral luminance information for the pattern image 512B that changes periodically along the lateral direction, and measures the lateral contrast value Kb. It also measures the diagonal contrast value Kc for the pattern image 512C that changes periodically along the diagonal direction, and measures the diagonal contrast value Kd for the pattern image 512D that changes periodically along the diagonal direction.

[0093] Furthermore, the control unit 80 calculates the overall contrast value K' of the pattern target image 500 at a certain position on the pattern target board 313 by averaging the contrast values ​​Ka~Kd in the vertical, horizontal, and diagonal directions. The control unit 80 may also calculate the overall contrast value K' for each pattern target image 500 associated with the position on the pattern target board 313. This makes it possible to measure the contrast value K' corresponding to the position on the pattern target board 313 (i.e., the contrast value K' corresponding to the spherical power of the eye E being examined).

[0094] <Output of change information> The measurement results for the refractive power and contrast information of the eye E under examination are both displayed on the display unit 16. As mentioned above, the measurement results for the refractive power of the eye E under examination may not be accurate, but they may be displayed as reference values. In addition, the contrast information of the eye E under examination may be displayed as information on the change in contrast value relative to the diopter information of the eye E under examination.

[0095] Figure 7 shows an example of information on the change in contrast value with respect to the diopter information of the eye E under examination. In this embodiment, a graph 700 is output showing the distribution of the contrast value K' with respect to the diopter information (spherical frequency) of the eye E under examination. Note that since the change in the spherical frequency of the eye E under examination corresponds to the change in the position of the pattern target plate 313, it can also be represented as a graph showing the distribution of the contrast value K' with respect to the position of the pattern target plate 313. Multiple contrast values ​​K' with different spherical frequencies of the eye E under examination are plotted in graph 700. For example, at least the peak value P of the contrast value K' and the values ​​around the peak value P may be plotted. Note that the values ​​around the peak value P may be a predetermined range of spherical frequencies, or they may be changed to an arbitrary range. For example, they may be values ​​within the range of an absolute value of 1.0 relative to the peak value P (range R in Figure 7).

[0096] Figure 8 shows an example of a graph corresponding to the eye E being examined. Figure 8(a) shows the case where eye E is an eye without an intraocular lens implanted. Figure 8(b) shows the case where eye E is an eye with a monofocal intraocular lens implanted. Figure 8(c) shows the case where eye E is an eye with an EDoF intraocular lens implanted. Figure 8(d) shows the case where eye E is an eye with a multifocal intraocular lens implanted. The horizontal axis represents the spherical power of eye E, and the vertical axis represents the contrast value K'.

[0097] If the eye E is an eye without an intraocular lens implanted, Graph 700 will plot data including one peak value P1 and at least a portion of the range R1 relative to peak value P1. If the eye E has a monofocal intraocular lens implanted, Graph 700 will plot data including one peak value P2 and at least a portion of the range R2 relative to peak value P2. If the eye E has an EDoF intraocular lens implanted, Graph 700 will plot data including one peak value P3 and at least a portion of the range R3 relative to peak value P3. If the eye E has a multifocal intraocular lens implanted, Graph 700 will plot data including multiple peak values ​​and ranges of spherical power relative to each peak value. For example, data including two peak values ​​P41 and P42 and spherical power ranges R41 and R42 will be plotted.

[0098] When the examiner identifies a single peak in Graph 700, they can easily determine whether the eye E under test is an eye without an intraocular lens (IOL), an eye with a monofocal IOL, or an eye with an EDoF IOL. Furthermore, the difference between an eye without an IOL, an eye with a monofocal IOL, and an eye with an EDoF IOL can be determined by the width of the single peak. For example, the width of the single peak will be wider in an eye with an EDoF IOL compared to an eye without an IOL or an eye with a monofocal IOL. Additionally, when the examiner identifies a double peak in Graph 700, they can easily determine whether the eye under test E has a multifocal IOL (bifocal IOL). Moreover, if the IOL is multifocal, the distribution of contrast values ​​K' allows the examiner to understand the near focal position relative to the far focal position, the distribution of light between far and near, etc.

[0099] Furthermore, examiners can prescribe lenses to the eye under examination that take into account the information obtained from contrast data. For example, if the eye under examination has a monofocal intraocular lens or an ED-OF intraocular lens implanted and the examiner wants to prescribe glasses to compensate for near vision, they can determine the lens power while considering this information. Also, for example, if the eye under examination needs to have a new intraocular lens added or a new intraocular lens changed, the examiner can select the lens power while considering how the current intraocular lens performs. For example, by showing the characteristics of the intraocular lens from the information on the change in contrast value K' with respect to the spherical power of the eye under examination E, it becomes easier to imagine the necessary prescription for the eye under examination.

[0100] If the eye under examination (E) has a monofocal, EDoF, or multifocal intraocular lens implanted, a peak α corresponding to false resolution may appear in Graph 700. For example, the peak α that appears when the contrast value K' temporarily drops to zero as the spherical power of eye E changes, but then increases again, is the peak corresponding to false resolution. The examiner can determine the presence or absence of false resolution by observing the change in the contrast value K'.

[0101] False resolution of contrast value K' can also be distinguished at the image processing stage of the pattern target image 500. For example, normally, the arrangement of white and black in the striped pattern on the pattern target board 313 matches the arrangement of white and black in the striped pattern on the pattern target image 500. However, in the case of false resolution, the arrangement of white and black in the striped pattern on the pattern target image 500 is reversed compared to the arrangement of white and black in the striped pattern on the pattern target board 313. For this reason, the control unit 80 may treat the false resolution portion of contrast value K' as zero and display it on the graph 700. The control unit 80 may also notify that false resolution is included in contrast value K' by changing the color of the line, displaying a message, etc.

[0102] In this embodiment, the pattern target image 500 may be displayed along with the graph 700 described above. For example, the pattern target image 500 may be displayed for each predetermined spherical power (for example, for every 1.0D change). Alternatively, for example, the pattern target image 500 corresponding to at least the peak value P may be displayed. Alternatively, for example, the pattern target image 500 corresponding to at least the peak value P and the values ​​around the peak value P may be displayed. In the second measurement optical system 300, the reflected light beam from the fundus passes through the entire pupil region (effective diameter of the eye under test E) and is captured by the image sensor 322. Therefore, the pattern target image 500 can be considered as the actual appearance of the pattern target plate 313 (how it appears when the distant image and the near image overlap). Accordingly, by displaying the pattern target image 500, the appearance of the eye under test E can be intuitively understood.

[0103] In this embodiment, the field of clear vision of the eye E may also be displayed along with the graph 700 described above. The field of clear vision of the eye E may be defined as the region in which the eye E can focus. For example, the field of clear vision may be shown by determining at least the far point (for example, the peak value P) from the distribution of the contrast value K' with respect to the spherical power of the eye E. The width of the field of clear vision may be set in advance as a fixed value, or it may be changed to an arbitrary value.

[0104] Of course, the clear vision range of the eye under examination E may be indicated by a method other than those described above. For example, the clear vision range may be indicated as the range in which the contrast value K' is equal to or greater than a predetermined percentage of the peak value P of the contrast value K' with respect to the spherical power of the eye under examination E. Alternatively, the clear vision range may be indicated as the range in which the contrast value K' with respect to the spherical power of the eye under examination E is equal to or greater than a predetermined threshold. Furthermore, the clear vision range may be determined based on the subjective refractive power and visual acuity of the eye under examination E.

[0105] Of course, along with the graph 700 mentioned above, both the pattern target image 500 and the clear vision area of ​​the eye E being examined may also be displayed.

[0106] In this embodiment, a graph 700 showing the contrast value K' for the spherical power of one eye E may be displayed. Alternatively, a graph 700 showing the contrast value K' for the spherical power of both eyes E may be displayed. In this case, two curves may be displayed by superimposing the contrast value K' for the spherical power of the left eye and the contrast value K' for the spherical power of the right eye, or a single curve may be displayed by combining the contrast value K' for the spherical power of the left eye and the contrast value K' for the spherical power of the right eye. When combining each contrast value K', at least one of the following processes may be performed: addition, averaging, weighting, etc. This allows for consideration of the binocular vision function of the eye E.

[0107] As explained above, for example, the ophthalmic device of this embodiment acquires the optical properties of the eye under examination and also acquires multiple contrast information sources with at least different diopter information in the eye under examination, and outputs information on the change in contrast information relative to the diopter information. This makes it easier to determine whether the eye under examination is an eye with an intraocular lens implanted. Furthermore, if the eye under examination is an eye with an intraocular lens implanted, it becomes easier to determine what kind of lens has been implanted. In addition, it is possible to determine whether the measurement results of the optical properties of the eye under examination (for example, refractive power) are appropriate by using the contrast information. Moreover, it is possible to obtain information on the characteristics of the intraocular lens from the change information, making it easier to derive an appropriate prescription for the eye under examination.

[0108] Furthermore, for example, the ophthalmic device of this embodiment includes, as change information, first data indicating the peak value of contrast information relative to diopter information. This makes it possible to determine, for example, the positions of the far and near points of the eye being examined.

[0109] Furthermore, for example, the ophthalmic device of this embodiment includes, as change information, second data showing peripheral values ​​relative to first data of contrast information relative to diopter information. This makes it possible to predict how the characteristics of the intraocular lens will change before and after the position of the far and near points of the eye being examined. In addition, by being able to predict the characteristics of the intraocular lens, it becomes possible to infer the type of intraocular lens.

[0110] Furthermore, for example, the ophthalmic device in this embodiment outputs a graph showing the distribution of contrast information relative to diopter information as change information. This makes the relationship between diopter information and contrast information visually easy to understand, making it easier to predict the characteristics of intraocular lenses and to infer the type of intraocular lens.

[0111] Furthermore, for example, the ophthalmic device of this embodiment outputs a graph that continuously shows the change in contrast information in response to changes in diopter information. This makes it easy to understand the positions of the far and near points of the eye under examination, the changes in the characteristics of the intraocular lens before and after the far and near points, etc. It also makes it easy to determine the type of intraocular lens inserted in the eye under examination. When eyeglasses or other corrective lenses are needed for the eye under examination E, it becomes possible to determine the amount of correction by considering this information. In addition, for example, when it is necessary to add or change an intraocular lens in the eye under examination, it becomes easier to select an appropriate lens.

[0112] Furthermore, for example, the ophthalmic device of this embodiment acquires contrast information with different diopter information based on the optical properties of the eye under examination. For example, contrast information with different diopter information may be acquired based on the refractive power of the eye under examination. In this case, the position of the optical properties (refractive power) of the eye under examination, or the position around the optical properties (refractive power) of the eye under examination, can be considered as the position of the far point of the eye under examination. As a result, it becomes easier to capture changes in the characteristics of the intraocular lens inserted into the eye under examination, and it becomes easier to determine the necessary prescription for the eye under examination.

[0113] Furthermore, in the ophthalmic device of this embodiment, for example, the second measuring light beam projected to acquire contrast information of the eye under examination is a patterned light beam, and a periodically changing index pattern image is detected by the second reflected light beam of the second measuring light beam from the fundus, and contrast information is acquired based on the luminance information in this index pattern image. For example, by using a periodically changing patterned light beam, contrast information of the eye under examination can be easily acquired. In addition, optical characteristics based on the contrast information of the eye under examination can be acquired. Moreover, by using periodically changing patterned light beams in multiple different directions, astigmatism information of the eye under examination (e.g., cylindrical power, astigmatism axis angle, etc.) can also be calculated.

[0114] Furthermore, for example, the ophthalmic apparatus of this embodiment includes a first light projection optical system that projects a first measurement light beam toward the fundus of the eye under examination, and a first light receiving optical system that detects the first reflected light beam, which is the first measurement light beam reflected from the fundus, as a first index pattern image using a first detector, and a contrast measurement optical system for acquiring contrast information of the eye under examination, and the first and second detectors are configured as different detectors. This makes it possible to acquire refractive power and contrast information without complicating each optical system.

[0115] Furthermore, for example, in the ophthalmic device of this embodiment, the first light-receiving optical system detects the first reflected light beam that has passed through the pupil division region, which is a division of the pupil region of the eye under examination, as a first index pattern image using the first detector, and the second light-receiving optical system detects the second index pattern image of the second reflected light beam that has passed through the pupil region of the eye under examination using the second detector. Since the second light-receiving optical system detects the reflected light beam that has passed through the effective diameter of the eye under examination, it is possible to obtain contrast information that reflects the actual vision of the eye under examination.

[0116] Furthermore, in the ophthalmic apparatus of this embodiment, for example, the optical path of the first light-emitting optical system and the optical path of the first light-receiving optical system are branched by a first optical path branching member, the optical path of the first light-receiving optical system and the optical path of the second light-receiving optical system are branched by a second optical path branching member, and the second optical path branching member is placed between the first optical path branching member and the pattern optical member, thereby placing the first detector and the second detector in different optical paths. For example, if the first detector and the second detector are used interchangeably and placed in the same optical path, the second reflected light beam passes through the pattern optical member, causing the second index pattern image to be divided into multiple images, making it difficult to acquire contrast information. However, by branching the optical path before the second reflected light beam passes through the pattern optical member, the second index pattern image can be detected as a single image, and contrast information can be appropriately acquired.

[0117] Furthermore, for example, in the ophthalmic device of this embodiment, the first measuring luminous beam for measuring the refractive power of the eye under examination is an infrared luminous beam, and the second measuring luminous beam for measuring the contrast information of the eye under examination is a visible luminous beam. As a result, the subject is less likely to feel glare when the first measuring luminous beam is projected, pupillary constriction is suppressed, and the refractive power can be determined with accuracy. In addition, as a result, contrast information can be obtained well regardless of whether the eye under examination has an intraocular lens implanted or not. Note that if the second measuring luminous beam is an infrared luminous beam, there is a possibility that contrast information cannot be measured correctly depending on the type of intraocular lens (especially multifocal intraocular lenses), but if it is a visible luminous beam, it can be used with various intraocular lenses and contrast information can be determined with accuracy.

[0118] <Example of transformation> In this embodiment, the projection optical system 110 of the first measurement optical system 100 was described using as an example a configuration in which the light source 111 emits an infrared luminous flux as the measurement luminous flux, but the embodiment is not limited to this. For example, an optical element for limiting a specific wavelength may be placed in the optical path of the measurement luminous flux from the light source 111. Similarly, in this embodiment, the projection optical system 310 of the second measurement optical system 300 was described using as an example a configuration in which the light source 311 emits a visible luminous flux as the measurement luminous flux, but the embodiment is not limited to this. For example, an optical element for limiting a specific wavelength may be placed in the optical path of the measurement luminous flux from the light source 311. For example, the optical element for limiting the wavelength of each measurement luminous flux may be a cut filter or the like.

[0119] In this embodiment, a configuration in which the measurement beam from the projection optical system 310 is a visible light beam has been described as an example, but the invention is not limited to this. The measurement beam from the projection optical system 310 may also be an infrared light beam. In this case, the eye under examination E will feel less glare during the measurement of the contrast value, and the burden will be reduced. On the other hand, if the eye under examination E is an eye with a multifocal intraocular lens implanted, in particular, a diffraction type that distributes the visible light beam to far and near using the principle of diffraction may not be able to obtain measurement results if an infrared light beam is used. For this reason, the ophthalmic device 10 may be equipped with a visible light source and an infrared light source as the light source 311 of the projection optical system 310, and the contrast value K' may be determined by switching between them as needed. For example, if measurement results cannot be obtained using the infrared light source, the device may switch to the visible light source to obtain measurement results.

[0120] In this embodiment, the acquisition of contrast information from the eye E under examination was described using a configuration in which both a fixation target and a pattern target are presented to the eye E under examination as an example, but the embodiment is not limited to this. In this embodiment, since both the measurement light beam from the projection optical system 310 and the fixation light beam from the fixation target presentation optical system 150 are visible light beams, the fixation target and the pattern target may appear superimposed on the eye E under examination. For this reason, when acquiring contrast information from the eye E under examination, only the pattern target may be presented, and the configuration may be such that the pattern target also serves as the fixation target.

[0121] Furthermore, when acquiring contrast information from the eye E under examination, the measurement light beam from the projection optical system 310 is a visible light beam, which may cause the eye E to feel glare and constrict its pupil during contrast value measurement. For this reason, the light intensity of the light source 311 illuminating the pattern target plate 313 may be adjusted so that the pattern target is presented to the eye E under examination at a brightness similar to or lower than that of the fixation target. In addition, the exposure time and gain of the image sensor 322 may be adjusted to make the pattern target image easier to detect.

[0122] In this embodiment, when acquiring contrast information of the eye E under examination, a configuration in which the fixation target plate 155 is moved along with the movement of the pattern target plate 313 relative to the eye E under examination was described as an example, but the embodiment is not limited to this. For example, if the eye E under examination is an eye without an intraocular lens implanted, accommodation may occur as a result of the movement of the fixation target plate 155. For this reason, the fixation target plate 155 may be fixed in place.

[0123] In this embodiment, we have described an example configuration in which the contrast value K' is measured with the pattern target plate 313 placed at the measurement start position D1 where the spherical power of the eye E becomes 0D, based on the measurement result of the refractive power of the eye E being examined. However, we are not limited to this configuration. If the refractive power of the eye E being examined is not measured correctly, the peak value P of the contrast value K' will not necessarily fall at the distance where the spherical power of the eye E becomes 0D (or at a distance closer than 0D).

[0124] Figure 9 shows an example where the peak value appears at a distance different from the spherical power of 0D. For example, if the pattern target plate 313 is moved from the measurement start position D1 (the distance of spherical power 0D) and such a graph 700 is obtained, the contrast value K' at the measurement start position D1 becomes the peak value Px. However, it is not possible to know how the contrast value K' changes at distances farther than the measurement start position D1, and in reality, the true peak value Py may appear at a distance of spherical power + 1.0D. For this reason, a predetermined distance at which the spherical power of the eye under test E becomes a positive value (for example, spherical power + 2.0D) may be set in advance as the measurement start position D1. Alternatively, the measurement start position D1 may be set arbitrarily. Furthermore, if the pattern target plate 313 is moved closer from the distance of spherical power 0D and the peak value is at the distance of spherical power 0D, the pattern target plate 313 may be moved further away than the distance of spherical power 0D to detect whether or not there is a true peak value.

[0125] In this embodiment, a configuration in which a graph 700 with spherical power on the horizontal axis is output as diopter information for the eye E under examination was described as an example, but the embodiment is not limited to this. The diopter information for the eye E under examination may be cylindrical power or astigmatism axis angle. In this case, the second measuring optical system 300 may have a configuration for changing the cylindrical power of the eye E under examination, or a configuration for changing the astigmatism axis angle of the eye E under examination. For example, it may have two rotatable cylindrical lenses.

[0126] In this embodiment, we have described an example configuration that outputs a graph 700 plotting the overall contrast value K' obtained by averaging the contrast values ​​Ka to Kd in each direction included in the pattern target image 500, but we are not limited to this. For example, a configuration that outputs a graph 700 plotting contrast values ​​in at least two directions separately is also possible. As an example, the contrast value Ka in the vertical direction and the contrast value Kb in the horizontal direction may be plotted separately. In this case, the contrast values ​​Ka and Kb may be displayed on a single graph, or they may be displayed as separate graphs.

[0127] In this embodiment, a configuration that outputs a graph 700 showing the relationship between the spherical power of the eye E under examination and the contrast value K' was described as an example, but the embodiment is not limited to this. If the pattern target image 500 includes pattern images in at least three directions, a graph showing the relationship between the spherical power of the eye E under examination and the peak contrast value P in each direction may be output. This makes it possible to calculate the refractive power of the eye E based on its contrast value.

[0128] Figure 10 is an example of Graph 750 showing the relationship between the spherical power of the eye E under examination and the peak contrast value P in each direction. The horizontal axis represents the direction (angle) of the pattern image, and the vertical axis represents the spherical power of the eye E under examination. For example, by plotting the peak contrast value Pa in the horizontal (90-degree) pattern image 512A, the peak contrast value Pb in the vertical (180-degree) pattern image 512B, the peak contrast value Pc in the diagonal (45-degree) pattern image 512C, and the peak contrast value Pd in ​​the diagonal (135-degree) pattern image 512D, a frequency distribution curve G passing through each peak value can be obtained. For example, the control unit 80 may calculate the refractive power of the eye E under examination by setting the maximum value in the frequency distribution curve G as the spherical power SPH, the difference between the maximum and minimum values ​​as the cylindrical power CYL, and the direction (angle) of the maximum value as the astigmatism axis angle AXIS.

[0129] In the above configuration, the first refractive power (first spherical power, first cylindrical power, and first astigmatism axis angle) based on the refractive power measurement of the eye E under examination and the second refractive power (second spherical power, second cylindrical power, and second astigmatism axis angle) based on the contrast measurement of the eye E under examination are obtained, so the first refractive power may be corrected based on the second refractive power. For example, in an eye with an intraocular lens implanted, the spherical power of the eye E under examination may be calculated with a shifted value when measuring the refractive power using the first measurement optical system 100. Also, cylindrical power and astigmatism axis angle may be calculated even though the eye E under examination does not have astigmatism. For this reason, the control unit 80 may correct the value of the first refractive power by determining the amount of shift between the first and second refractive powers and adding (or subtracting) the amount of shift to the first refractive power. For example, the value of the first spherical power may be corrected to the value of the second spherical power. Furthermore, for example, the value of the first cylindrical power may be corrected to the value of the second cylindrical power. Also, for example, the value of the first astigmatic axis angle may be corrected to the value of the second astigmatic axis angle. A predetermined tolerance range may be set for the difference between the refractive power of the first eye and the refractive power of the second eye, and if this tolerance range is exceeded, the correction may be performed.

[0130] In this case, whether or not to correct the first eye's refractive power to the second eye's refractive power of the eye under examination E may be determined based on the ring image captured by the first measurement optical system 100 (i.e., the ring image used when calculating the first eye's refractive power). For example, in the fitting of a circle using the pixel positions of at least three points in the ring image, if there are large errors in shape or radius of curvature, the first eye's refractive power may be corrected to the second eye's refractive power.

[0131] The ophthalmic device of this embodiment corrects the measurement results of the optical properties (refractive power) of the eye under examination based on the contrast information of the eye under examination. For example, even if the eye under examination is an eye with an intraocular lens implanted and the measurement results of the optical properties of the eye under examination are not properly obtained, the accuracy of the measurement results can be improved by correcting them using contrast information.

[0132] In this embodiment, a configuration in which contrast information for the diopter information of the eye E under examination is output as graph 700 has been described as an example, but the embodiment is not limited to this. For example, a graph of contrast information that reflects the prescription for the eye under examination may be output. For example, when correcting the eye under examination with eyeglasses, a graph that takes into account the amount of correction may be output. More specifically, when -3.0D is added to the eye under examination, the contrast value K' may be shifted by an amount equivalent to -3.0D. In other words, the peak value P and the values ​​around it may be shifted by an amount equivalent to -3.0D. When an additional correction amount is added to the eye under examination in this manner, the clear vision ranges of both eyes may be output together so that the binocular vision of the eye under examination can be easily understood.

[0133] In this embodiment, a configuration in which contrast measurement is performed on the eye E after refractive power measurement is described as an example, but the embodiment is not limited to this. In this embodiment, only contrast measurement on the eye E may be performed. In this case, by moving the pattern target plate 313 from the upper limit to the lower limit of its movable range, a graph 700 including the peak value of the contrast value and values ​​around it can be obtained.

[0134] In this embodiment, the ophthalmic device 10 is described as a so-called refractive power measuring device capable of acquiring the refractive power of the eye under examination, and the configuration for acquiring contrast information is described as an example, but the embodiment is not limited to this. The ophthalmic device 10 may also be a so-called wavefront aberration measuring device capable of acquiring the optical characteristics of the eye under examination. More specifically, it may be a wavefront aberration measuring device equipped with an optical system that divides and detects the reflected light beam from the fundus using a Shack-Hartmann sensor. For example, even with a wavefront aberration measuring device, the graph 700 may be acquired and output by measuring the contrast of the eye under examination E.

[0135] Furthermore, in this embodiment, the ophthalmic device 10 was described using as an example a configuration in which the light source 111 of the projection optical system 110 and the light source 311 (pattern target plate 313) of the projection optical system 310 are arranged in different optical paths, and the image sensor 126 of the light-receiving optical system 120 and the image sensor 322 of the light-receiving optical system 320 are arranged in different optical paths, but the embodiment is not limited to this. For example, each light source may be arranged in a different optical path, and each image sensor may be arranged in the same optical path (i.e., shared). In this case, a ring image for measuring refractive power may be projected onto the fundus of the eye under examination, and a pattern image for acquiring contrast information may be projected onto the fundus of the eye under examination, and each image may be detected by a single image sensor. [Explanation of Symbols]

[0136] 10 Ophthalmological equipment 80 Control Unit 100 1st measurement optical system 200 Observation Optical System 150 Fixation target presentation optical system 300 Second measurement optical system 400 Index projection optical system 600 Alignment Index Projection Optical System

Claims

1. An ophthalmic device for objectively measuring the optical properties of the eye under examination, An optical system for measuring refractive power of an eye, comprising: a first light projection optical system that projects a first measurement light beam toward the fundus of the eye under examination; and a first light receiving optical system that detects the first reflected light beam, which is the first measurement light beam reflected from the fundus, as a first indicator pattern image using a first detector, wherein the optical system for measuring refractive power of the eye under examination is provided, A contrast measurement optical system for acquiring contrast information related to the contrast of the eye under examination, comprising: a second light projection optical system that projects a periodically changing patterned second measurement light beam toward the fundus of the eye under examination; and a second light receiving optical system that detects a periodically changing second index pattern image formed by a second reflected light beam reflected from the fundus of the eye under examination using a second detector; Equipped with, An ophthalmic device characterized in that the first detector and the second detector are different detectors positioned at conjugate locations in the fundus.

2. In the ophthalmic device of Claim 1, The second light projection optical system projects the periodically changing light beam along a plurality of different directions as the second measurement light beam. The ophthalmic device is characterized in that the second light-receiving optical system detects the image of a light beam that changes periodically along a plurality of different directions as the second index pattern image.

3. In the ophthalmic device according to claim 1 or 2, The first light-receiving optical system detects the first reflected light beam that has passed through the pupil division region, in which the pupil region of the eye under examination is divided, as a first indicator pattern image using the first detector. The ophthalmic device is characterized in that the second light-receiving optical system detects the second indicator pattern image formed by the second reflected light beam that has passed through the pupil region of the eye under examination using the second detector.

4. In any of the ophthalmic devices according to claims 1 to 3, The ophthalmic apparatus is characterized in that the first light-receiving optical system has a pattern optical member for focusing a first reflected light beam from the fundus of the eye as a pattern light beam onto a first detector, and the pattern optical member causes the first indicator pattern image to be detected by the first detector.

5. In the ophthalmic device of claim 4, The pattern optical member is a ring optical member for focusing the first reflected light beam from the fundus of the eye as a ring light beam onto the first detector, and the ophthalmic device is characterized in that the ring optical member causes the first detector to detect a ring image as a first indicator pattern image.

6. In the ophthalmic device of claim 4 or 5, A first optical path branching member that branches the optical path of the first light-emitting optical system and the optical path of the first light-receiving optical system, A second optical path branching member that branches the optical path of the first light-receiving optical system and the optical path of the second light-receiving optical system, Equipped with, An ophthalmic apparatus characterized by arranging the first detector and the second detector in different optical paths by arranging the second optical path branching member between the first optical path branching member and the pattern optical member. An ophthalmic device.

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