JP2020039848A - Ophthalmologic apparatus - Google Patents

Abstract

To provide an ophthalmologic apparatus capable of automatically and accurately examining strabismus and phoria of the eye to be tested.SOLUTION: An ophthalmologic apparatus 10 has: a pupil center detection part 27c which detects pupil centers of the right eye to be tested and the left eye to be tested from anterior eye part images of the right eye to be tested and the left eye to be tested acquired by a display 32a; a corneal reflex position detection part 27d detecting positions of corneal reflexes of the right eye to be tested and the left eye to be tested on the basis of point images obtained by light beams parallel to optical axes incident to the right eye to be tested and the left eye to be tested from a measurement optical system 21 forming images in the right eye to be tested and the left eye to be tested; and a visual axis calculation part 27e calculating visual axes of the right eye to be tested and the left eye to be tested on the basis of the pupil centers and positions of the corneal reflexes.SELECTED DRAWING: Figure 5

Description

  The present invention relates to an ophthalmologic apparatus capable of inspecting a strabismus of an eye to be examined.

  2. Description of the Related Art Conventionally, it has been known that correction of strabismus and oblique position is performed using glasses (prism glasses). Further, the examination of the strabismus and the oblique position is manually performed by an ophthalmologist, a vision trainer, or a clerk of an optician by a manual examination requiring skill and experience.

Japanese Patent No. 5011144

  However, manual examination of strabismus and oblique position is difficult to perform in a spectacle shop with few staff members having ophthalmological expertise because the results are easily affected by the knowledge and skill of the examiner.

  On the other hand, it is known that uncorrection of strabismus and obliqueness is known to contribute to eyestrain. The potential demand to do is high.

  It should be noted that an ophthalmologic measurement device has been proposed which detects the direction of the line of sight of the eye when the visible light is transmitted to the eye or when the visible light is transmitted after the visible light is blocked (Patent Document 1). Reference), even with such a device, it was difficult to precisely measure the squint and oblique position of the eye to be examined.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an ophthalmologic apparatus capable of automatically and precisely inspecting a squint and an oblique position of a subject's eye.

  In order to achieve the object, the ophthalmologic apparatus of the present invention includes a pair of measurement heads each storing a measurement optical system that acquires eye information of the right eye or the left eye of the subject, and a measurement optical system. Provided, an image acquisition unit that acquires an anterior eye image on the optical axis of the measurement optical system of the right eye or the left eye, and an anterior eye image of the right eye and the left eye acquired by the image acquisition unit. A pupil center detection unit that detects the pupil center of the right eye and the left eye, and a light beam parallel to the optical axis that is incident on the right eye and the left eye from the measurement optical system in the right eye and the left eye. A corneal reflection position detection unit that detects the positions of the corneal reflections of the right eye and the left eye based on the point images obtained by imaging, and the right eye and the left eye based on the pupil center and the position of the corneal reflection. A visual axis calculation unit that calculates the visual axis of the optometry.

  In the ophthalmologic apparatus of the present invention configured as described above, the visual axis calculation unit calculates the visual axes of the right eye and the left eye based on the detection results obtained by the pupil center detection unit and the corneal reflection position detection unit. .

  Therefore, according to the ophthalmologic apparatus of the present invention, it is possible to automatically and precisely perform the examination of the perspective and the oblique position of the eye to be inspected.

FIG. 1 is a perspective view illustrating an overall configuration of an ophthalmologic apparatus according to an embodiment. FIG. 2 is a diagram illustrating a detailed configuration of a measurement optical system for the right eye of the ophthalmologic apparatus according to the present embodiment. It is a perspective view showing an example of a rotary prism used for the ophthalmologic apparatus which is this embodiment. FIG. 1 is a block diagram illustrating an overall configuration of an ophthalmologic apparatus according to an embodiment. FIG. 3 is a block diagram illustrating a configuration of a control system of the ophthalmologic apparatus according to the present embodiment. FIG. 3 is a schematic diagram illustrating a relationship between a visual axis and a pupil axis of an eye to be examined. FIG. 3 is a diagram illustrating a point image formed inside an eye to be examined by a point light source. It is a figure which shows the type of perspective. FIG. 5 is a diagram illustrating a pupil center and a position of corneal reflection in an anterior segment image acquired by an ophthalmologic apparatus. It is a figure for explaining the schematic diagram showing the position of a pupil center and a corneal reflex. It is a figure which shows the deviation | shift amount of the position of the corneal reflection with respect to the position of a pupil center. FIG. 3 is a diagram for explaining an angle between an optical axis and a pupil axis. FIG. 3 is a diagram for explaining a rotation state of a measurement head by a measurement head control unit. 5 is a flowchart for explaining the operation of the ophthalmologic apparatus 10 according to the present embodiment. FIG. 5 is a diagram illustrating an example of a screen displayed on a display unit of the ophthalmologic apparatus according to the present embodiment.

Hereinafter, the ophthalmologic apparatus according to the present embodiment will be described with reference to FIGS. First, the overall configuration of the ophthalmologic apparatus 10 will be described.
(Overall configuration of ophthalmic device)

  As shown in FIG. 1, the ophthalmologic apparatus 10 includes a base 11, an optometry table 12, a support 13, an arm 14, a drive mechanism (drive unit) 15, and a pair of measurement heads 16. In the ophthalmologic apparatus 10, the subject facing the optometry table 12 acquires information on the subject's eye to be examined in a state where the subject applies his forehead to the forehead contact part 17 provided between the two measurement heads 16. . As shown in FIG. 1 throughout this specification, the X axis, the Y axis, and the Z axis are taken, and when viewed from the subject, the left-right direction is the X direction, the up-down direction (vertical direction) is the Y direction, and the X direction is the X direction. A direction orthogonal to the Y direction (the depth direction of the measuring head 16) is defined as a Z direction.

  The optometry table 12 is a desk on which a display unit / examiner controller (hereinafter, simply referred to as an examiner controller 25) 25 and a controller 26 for the examinee, which are described later, are placed, and those used for optometry are placed. And is supported by the base 11. The optometry table 12 may be supported by the base 11 so that the position (height position) in the Y direction can be adjusted.

  The column 13 is supported by the base 11 so as to extend in the Y direction at the rear end of the optometry table 12, and an arm 14 is provided at the tip.

  The arm 14 suspends both measurement heads 16 on the optometry table 12 via the drive mechanism 15, and extends in the Z direction from the support 13 to the near side. The arm 14 is movable in the Y direction with respect to the support 13. Note that the arm 14 may be movable in the X direction and the Z direction with respect to the support 13. A pair of measuring heads 16 are supported at the tip of the arm 14 by being suspended by a driving mechanism 15.

  The measurement heads 16 are provided in pairs to individually correspond to the left and right eyes to be examined of the subject. Hereinafter, when individually described, they are referred to as a left-eye measurement head 16L and a right-eye measurement head 16R. . The measurement head 16L for the left eye acquires information on the eye to be examined on the left side of the subject, and the measurement head 16R for the right eye acquires information on the eye to be examined on the right side of the subject. The measurement head 16L for the left eye and the measurement head 16R for the right eye are configured to be plane-symmetric with respect to a vertical plane located between them in the X direction.

  Each of the measuring heads 16 is provided with a mirror 18 serving as a deflecting member, and information of the corresponding eye to be inspected is acquired through the mirror 18 by a measuring optical system 21 described later.

  Each measurement head 16 is provided with a measurement optical system 21 for acquiring eye information of the eye to be inspected (a right-eye measurement optical system 21R and a left-eye measurement optical system 21L when individually described). The detailed configuration of the measurement optical system 21 will be described later.

  Both measuring heads 16 are movably suspended by a drive mechanism 15 provided on a base 19 suspended from the tip of the arm 14. In the present embodiment, as shown in FIGS. 4 and 5, the drive mechanism 15 includes a left-eye vertical drive unit 22L, a left-eye horizontal drive unit 23L, and a left-eye rotation corresponding to the left-eye measurement head 16L. The drive unit 24L includes a right-eye vertical drive unit 22R, a right-eye horizontal drive unit 23R, and a right-eye rotation drive unit 24R corresponding to the right-eye measurement head 16R.

  The configuration of each drive unit corresponding to the measurement head 16L for the left eye and the configuration of each drive unit corresponding to the measurement head 16R for the right eye are plane-symmetrical with respect to a vertical plane located between them in the X direction. Therefore, when not individually described, they are simply referred to as a vertical drive unit 22, a horizontal drive unit 23, and a rotation drive unit 24 (see FIG. 4).

  As shown in FIG. 4, the vertical drive unit 22 is provided between the base unit 19 and the horizontal drive unit 23, and moves the horizontal drive unit 23 in the Y direction (vertical direction) with respect to the base unit 19. The horizontal drive unit 23 is provided between the vertical drive unit 22 and the rotation drive unit 24, and moves the rotation drive unit 24 in the X direction and the Z direction (horizontal direction) with respect to the vertical drive unit 22.

  The vertical drive unit 22 and the horizontal drive unit 23 are provided with an actuator that generates a driving force such as a pulse motor, and a transmission mechanism that transmits the driving force such as a combination of gears or a rack and pinion. It is composed. The horizontal driving unit 23 can be easily configured and can easily control the movement in the horizontal direction, for example, by providing a combination of an actuator and a transmission mechanism individually in the X direction and the Z direction.

  The rotation drive unit 24 rotates the corresponding measurement head 16 with respect to the horizontal drive unit 23 about the eyeball rotation axis of the corresponding eye to be examined. The rotation drive unit 24 includes, for example, a configuration in which a transmission mechanism that receives a driving force from an actuator moves along an arc-shaped guide groove. The measurement head 16 is rotated about the rotation axis of the eyeball.

  In addition, the rotation drive unit 24 supports the measurement head 16 so as to be rotatable around a rotation axis provided on the rotation drive unit 24 and cooperates with the horizontal drive unit 23 to rotate while changing the position where the measurement head 16 is supported. Good.

  Thereby, the drive mechanism 15 can move the measuring heads 16 individually or in conjunction with each other in the X direction, the Y direction, and the Z direction, and can rotate the measurement head 16 around the eyeball rotation axis of the eye to be examined. .

  As shown in FIGS. 1 and 5, the base 11 is provided with a control unit 27 that controls each unit of the ophthalmologic apparatus 10. The control unit 27 has a communication unit 27b capable of short-range wireless communication with the examiner controller 25.

  The examiner's controller 25 is an information processing device having a communication unit 25d capable of short-range communication with the control unit 27, such as a tablet terminal or a smartphone. The examiner controller 25 is used by the examiner to operate the ophthalmologic apparatus 10. The examiner controller 25 causes a predetermined screen to be displayed on the display surface 25a based on the display control signal sent from the control unit 27. A touch panel type input unit 25c is provided on the display surface 25a. The operation input signal received by the input unit 25c is sent to the control unit 27 via the communication unit 25d.

  In the ophthalmologic apparatus 10 of the present embodiment, the controller 25 for the examiner is configured to be portable, and may be operated in a state where the controller 25 is arranged on the table 12 for the examiner. It may be operated.

  The functional configuration of the ophthalmologic apparatus 10 will be described later in detail.

(Optical system of ophthalmic device)
FIG. 2 is a diagram illustrating a detailed configuration of the measurement optical system 21R for the right eye in the ophthalmologic apparatus according to the present embodiment. Note that the configuration of the left-eye measurement optical system 21L is the same as that of the right-eye measurement optical system 21R, and a description thereof will be omitted, and only the right-eye measurement optical system 21R will be described.

  The measurement optical system 21R for the right eye includes an observation system 31, a target projection system 32, an eye refractive power measurement system 33, an alignment system 35, an alignment system 36, and a kerato system 37, as shown in FIG.

  The observation system 31 observes the anterior segment of the eye E, the target projection system 32 presents a target to the eye E, and the eye refractive power measurement system 33 measures the eye refractive power.

  In the present embodiment, the eye refractive power measurement system 33 has a function of projecting a predetermined measurement pattern on the fundus oculi Ef of the eye E and a function of detecting an image of the measurement pattern projected on the fundus oculi Ef.

  The alignment system 35 and the alignment system 36 perform positioning (alignment) of the optical system with respect to the eye E to be inspected, and the alignment system 36 is arranged in the direction (the front-back direction) along the optical axis of the observation system 31 and the alignment system 36 is adjusted to the optical axis. Alignment is performed in directions perpendicular to (vertical and horizontal).

  The observation system 31 includes an objective lens 31a, a dichroic filter 31b, a half mirror 31c, a relay lens 31d, a dichroic filter 31e, an imaging lens 31f, and an image sensor (CCD: image acquisition unit) 31g.

  In the observation system 31, the light beam reflected by the eye E (anterior eye) is imaged on the image sensor 31g by the imaging lens 31f via the objective lens 31a. As a result, an anterior segment image E ′ is formed on the image sensor 31g, on which a keratling light beam, a light beam of the alignment light source 35a, and a light beam (bright spot image Br) of the alignment light source 36a are projected (projected). You. The image sensor 31g of the observation system 31 captures the anterior segment image E '. The control unit 27 displays an anterior ocular segment image E ′ and the like based on the image signal output from the image sensor 31g on the display surface 25a of the examiner controller 25.

  A kerato system 37 is provided in front of the objective lens 31a. The kerato system 37 includes a kerato plate 37a and a kerato ring light source 37b. The kerato plate 37a has a plate shape provided with a slit concentric with the optical axis of the observation system 31, and is provided near the objective lens 31a. The kerato ring light source 37b is provided in accordance with the slit of the kerato plate 37a.

  In the kerato-system 37, the luminous flux from the lit kerato-ring light source 37b passes through the slit of the kerato-plate 37a, so that the kerato-ring luminous flux (ring for measuring the corneal curvature) for the eye E (cornea Ec) is measured. The target is projected (projected). The kerattling light beam is reflected by the cornea Ec of the eye E to be examined, and is imaged on the image sensor 31g by the observation system 31. As a result, the image sensor 31g detects (receives) an image (image) of the ring-shaped kerat ring light beam, and the control unit 27 causes the display surface 25a to display the image of the measurement pattern, and the image (image sensor 31g) The corneal shape (radius of curvature) is measured by a well-known method based on the image signal from).

  In the present embodiment, an example (keratous system 37) is shown as a corneal shape measuring system in which a ring slit is about 1 to 3 times and a keratoplate 37a that measures curvature near the center of the cornea is used. As long as the corneal shape is measured, a platid plate having multiple rings and capable of measuring the shape of the entire cornea may be used, other configurations may be used, and the configuration is not limited to the configuration of the present embodiment.

  An alignment system 35 is provided behind the kerato system 37 (kerato plate 37a). The alignment system 35 has a pair of alignment light sources 35a and a projection lens 35b, converts the light flux from each alignment light source 35a into a parallel light flux with each projection lens 35b, and passes the cornea of the eye E through an alignment hole provided in the kerato plate 37a. The parallel light beam is projected (projected) on Ec.

  The control unit 27 or the examiner moves the measuring head 16 in the front-rear direction based on the bright spot (bright spot image) projected (projected) on the cornea Ec, so that the direction along the optical axis of the observation system 31 ( Alignment in the front-back direction). The alignment in the front-back direction is performed by adjusting the position of the measuring head 16 so that the ratio of the distance between two point images by the alignment light source 35a on the image sensor 31g and the diameter of the kerattling image is within a predetermined range.

  Here, the controller 27 may calculate the amount of alignment deviation from the ratio and display the amount of alignment deviation on the display surface 25a. Note that the alignment in the front-rear direction may be performed by adjusting the position of the measuring head 16 so that the bright spot image Br is focused by the alignment light source 36a described later.

  The observation system 31 is provided with an alignment system (parallel optical system) 36. The alignment system 36 has an alignment light source 36a and a projection lens 36b, and shares the half mirror 31c, the dichroic filter 31b, and the objective lens 31a with the observation system 31.

The alignment system 36 projects (projects) a light beam from an alignment light source (point light source) 36a to the cornea Ec of the eye E as a parallel light beam via the objective lens 31a. Parallel beam K which is projected onto the cornea Ec of the eye E from the alignment system 36, a substantially intermediate position of the corneal apex Ept and the corneal curvature center R _0, to form a bright spot Q alignment light (see FIG. 7). The control unit 27 or the examiner moves the measuring head 16 in the front-rear direction based on the image (bright spot image) Br of the bright spot Q projected (projected) on the cornea Ec, so that the optical axis of the observation system 31 is adjusted. Alignment is performed in the direction (vertical direction, horizontal direction) orthogonal to.

  At this time, the control unit 27 causes the display surface 25a to display an alignment mark AL serving as a guide of the alignment mark, in addition to the anterior eye image E 'on which the bright spot image Br is formed. The control unit 27 may be configured to control the measurement to be started when the alignment is completed.

The alignment light source 36a is movable on a plane orthogonal to the optical axis of the alignment system 36 by a point light source driving unit (see FIG. 5) 36c. When the alignment light source 36a is moved by the point light source driving unit 36c, the bright spot image Br projected on the cornea Ec also moves on the cornea Ec correspondingly.
The alignment light source 36a is a light emitting diode that emits infrared light (for example, 940 nm) in order to prevent the subject from visually recognizing the alignment light source 36a during the alignment operation by the alignment system 36.

  The optotype projection system 32 is an optical system that projects an optotype to fixate and cloud the eye to be inspected E and presents it to the fundus oculi Ef. The optotype projection system 32 includes a display 32a, rotary prisms 32A and 32B, an imaging lens 32b, a moving lens 32c, a relay lens 32d, a field lens 32f, a mirror 32h, and a dichroic filter 32i, a dichroic filter 31b and an objective lens 31a. Is shared with the observation system 31.

  The display 32a displays a landscape chart that performs fixation and fogging, a Landolt ring, an E-character optotype, an optometry optotype, and the like when performing an objective test and a subjective test.

  The display 32a can be formed of an EL (electroluminescence) or a liquid crystal display (LCD), and displays an arbitrary image under the control of the control unit 27. The display 32a is provided movably along the optical axis at a position conjugate with the fundus oculi Ef of the eye E on the optical path of the optotype projection system 32.

  The rotary prisms 32A and 32B are used to adjust the prism power and the prism base direction in the oblique inspection. The rotary prisms 32A and 32B are independently rotated by driving a pulse motor or the like (not shown). As shown in FIG. 3, when the rotary prisms 32A and 32B are rotated in opposite directions, the prism power is continuously changed, and when they are integrally rotated in the same direction, the prism base direction is continuously changed. .

  The movable lens 32c is driven forward and backward along the optical axis by a drive motor (not shown). By moving the moving lens 32c to the eye E, the refractive power can be displaced to the minus side, and by moving the moving lens 32c in a direction away from the eye E, the refractive power can be moved to the positive side. Can be displaced. Accordingly, the moving distance of the optotype displayed on the display 32a can be changed by moving the moving lens 32c forward and backward, that is, the presenting position of the optotype image can be changed, and the eye E to be examined can be fixed and fogged. it can.

  The eye-refractive-power measuring system 33 projects a ring-shaped luminous flux projection system 33A that projects a ring-shaped measurement pattern onto the fundus oculi Ef of the eye E, and a ring that detects (receives) reflected light of the ring-shaped measurement pattern from the fundus oculi Ef. It has a linear light beam receiving system 33B.

  The ring-shaped light beam projection system 33A has a reflex light source unit 33a, a relay lens 33b, a pupil ring stop 33c, a field lens 33d, a perforated prism 33e, and a rotary prism 33f, and shares a dichroic filter 32i with the target projection system 32. Then, the dichroic filter 31b and the objective lens 31a are shared with the observation system 31. The reflex light source unit 33a includes, for example, a reflex measurement light source 33g for reflex measurement using an LED, a collimator lens 33h, a conical prism 33i, and a ring pattern forming plate 33j. It can move integrally on the optical axis of the measurement system 33.

  The ring-shaped light beam receiving system 33B includes a hole 33p of a perforated prism 33e, a field lens 33q, a reflection mirror 33r, a relay lens 33s, a focusing lens 33t, and a reflection mirror 33u, and an objective lens 31a, a dichroic filter 31b, and a dichroic. The filter 31e, the imaging lens 31f, and the image sensor 31g are shared with the observation system 31, the dichroic filter 32i is shared with the target projection system 32, and the rotary prism 33f and the perforated prism 33e are shared with the ring light beam projection system 33A. .

  Next, the operation in the eye refractive power measurement mode will be described. The control unit 27 turns on the reflex measurement light source 33g, and moves the reflex light source unit 33a of the ring-shaped light beam projection system 33A and the focusing lens 33t of the ring-shaped light beam reception system 33B in the optical axis direction. In the ring-shaped light beam projection system 33A, the reflex light source unit 33a emits a ring-shaped measurement pattern, and advances the measurement pattern to the perforated prism 33e through the relay lens 33b, the pupil ring stop 33c, and the field lens 33d. The light is reflected by the reflection surface 33v and guided to the dichroic filter 32i via the rotary prism 33f. In the ring light beam projection system 33A, the measurement pattern is guided to the objective lens 31a through the dichroic filter 32i and the dichroic filter 31b, thereby projecting the ring measurement pattern on the fundus oculi Ef of the eye E to be inspected.

  In the ring-shaped light beam receiving system 33B, the ring-shaped measurement pattern formed on the fundus oculi Ef is condensed by the objective lens 31a, and is passed through the dichroic filter 31b, the dichroic filter 32i and the rotary prism 33f to the hole 33p of the perforated prism 33e. Let go. In the ring-shaped light beam receiving system 33B, the measurement pattern passes through the field lens 33q, the reflection mirror 33r, the relay lens 33s, the focusing lens 33t, the reflection mirror 33u, the dichroic filter 31e, and the imaging lens 31f, and is transmitted to the image sensor 31g. Make an image. Thereby, the image sensor 31g detects the image of the ring-shaped measurement pattern, and the controller 27 displays the image of the measurement pattern on the display surface 25a, and based on the image signal from the image (image sensor 31g), The spherical power, cylindrical power, and axis angle as eye refractive power are measured by a known method.

  In the eye-refractive-power measurement mode, the control unit 27 causes the display 32a to display a fixed fixation target in the target projection system 32. The luminous flux from the display 32a passes through rotary prisms 32A and 32B, an imaging lens 32b, a moving lens 32c, a relay lens 32d, a field lens 32f, a mirror 32h, a dichroic filter 32i, a dichroic filter 31b, and an objective lens 31a. Is projected (projected) on the fundus oculi Ef. The examiner or the control unit 27 performs the alignment while fixing the presented fixed fixation target to the subject, and based on the result of the provisional measurement of the eye refractive power (ref), moves to the far point of the eye E to be examined. After moving the moving lens 32c, the state is further changed to a cloudy state, and the eye refractive power at the time of accommodation suspension is measured.

  The configuration of the eye refractive power measurement system 33, the alignment system 35, the alignment system 36, the kerato system 37, and the like, and the principles of measurement of the eye refractive power (ref), subjective examination, and corneal shape (kerato) are known. Detailed description is omitted.

(Control system for ophthalmic equipment)
The functional configuration of the ophthalmologic apparatus 10 according to the present embodiment will be described with reference to FIG. The control unit 27 includes, in addition to the measurement optical system 21 described above, the vertical drive unit 22, the horizontal drive unit 23, and the rotation drive unit 24 as the drive mechanism 15, an examiner controller 25 and a subject controller 26. And the storage unit 28 are connected.

  The examiner controller 25 has a display unit 25b that displays a screen on the display surface 25a based on the display control signal transmitted from the control unit 27. On the display surface 25a of the display unit 25b, a touch panel type input unit 25c is provided. The display unit 25b displays a schematic diagram showing the pupil center and the position of the corneal reflection in the anterior ocular segment image E '. The display unit 25b displays the distance between a specific position at which the right eye and the left eye to fixate the fixation target and the right eye or the left eye by the measurement head control unit 27f described later. Further, the display unit 25b displays a cross-sectional view in which the visual axis and the optical axis of the right eye and the left eye are shown on the horizontal cross section of the right eye and the left eye. Details of the screen displayed by the display unit 25b will be described later.

  The examiner's controller 25 and the control unit 27 are capable of short-range wireless communication by communication units 25d and 27b provided in the examiner's controller 25 and the control unit 27, respectively.

  The subject controller 26 is used by the subject to respond when acquiring various kinds of eye information of the subject's eye. The subject controller 26 includes an input device such as a keyboard, a mouse, and a joystick. The control unit 27 is connected to the subject controller 26 via a wired or wireless communication path.

  The control unit 27 expands a program stored in the connected storage unit 28 or the built-in internal memory 27a on, for example, a RAM, and appropriately operates the controller 25 for the examiner or the controller 26 for the subject, It controls the operation of the ophthalmologic apparatus 10 as a whole, and functions as a pupil center detection unit 27c, a corneal reflection position detection unit 27d, a visual axis calculation unit 27e, a measurement head control unit 27f, and a point light source control unit 27g to be described later. In the present embodiment, the internal memory 27a is configured by a RAM or the like, and the storage unit 28 is configured by a ROM, an EEPROM, or the like.

  The pupil center detection unit 27c detects the pupil centers of the right eye and the left eye from the anterior eye images E ′ of the right eye and the left eye obtained by the imaging device 31g of the observation system 31. The corneal reflection position detection unit 27d determines whether the parallel light flux K (see FIG. 7) from the alignment light source 36a of the alignment system 36 forms an image in the right eye and the left eye, based on the bright spots Q obtained from these right and left eyes. The corneal reflection of the subject's eye and the left subject's eye, that is, the position of the bright spot image Br that is the image of the bright spot Q is detected. As shown in FIG. 7, when the parallel light flux K from the alignment light source 36a is incident on the eyeball, a spot-like image (Purkinje image) is formed at a position Q (half the radius of curvature r of the cornea, r / 2) inside the cornea Ec, That is, corneal reflection Br is formed. The visual axis calculation unit 27e obtains the visual axes of the right eye and the left eye based on the pupil center and the position of the corneal reflection. Further, the visual axis calculation unit 27e calculates the prism base direction and the prism power of the right eye and the left eye based on the calculated visual axes of the right eye and the left eye.

  At a specific position in front of the right eye and the left eye, the measurement head control unit 27f controls the fixation target displayed on the display 32a of the target projection system 32 by at least one of the right eye and the left eye. The measurement head 16 is rotated by the driving mechanism 15 so as to fixate the image.

  The point light source control unit 27g moves the alignment light source 36a by the point light source driving unit 36c so that the position of the corneal reflection substantially matches the center of the pupil.

  Further, in the ophthalmologic apparatus 10 according to the present embodiment, the anterior eye images EL ′ and ER ′ of the left eye EL and the right eye ER are displayed on the display unit 25b (see FIG. 15). For this reason, by visually recognizing these, the examiner can grasp, for example, the cause of the failure of the alignment or the inspection. In other words, as a cause of poor alignment or the like, for example, fixation is not possible, binocular vision is not possible, there is strabismus or obliqueness, there is ptosis, there is suppression, there is pupil miosis, The part is inclined. By visually recognizing the anterior eye images EL ′ and ER ′ of the left eye EL and the right eye ER displayed on the display unit 25b during the execution of the alignment or the like, the examiner can clearly determine the cause of the inability to perform the alignment or the like. It becomes possible to grasp. Then, corrective measures can be taken promptly by correcting the position of the head or calling attention to the subject, and the success rate of realignment and the like can be improved.

  The function realizing means of the control unit 27 will be described later in detail.

  As already described in detail, the measurement optical system 21 includes an observation system 31, a target projection system 32, an eye refractive power measurement system 33, an alignment system 35, an alignment system 36, and a kerato system 37.

(principle)
Next, the measurement principle of the ophthalmologic apparatus 10 according to the present embodiment will be described with reference to FIGS.

  The ophthalmologic apparatus 10 according to the present embodiment is an apparatus that quantitatively measures the strabismus of the eye E to be inspected. Here, the term “strabismus” means that the line of sight of the right eye and the left eye is directed to different places. In the case of the eye E having no squint, when the common eye is fixed by the right eye and the left eye, the line of sight of the right eye and the left eye is located at a common place (fixation target) substantially in front. Heading. However, when the eye E is oblique, the line of sight of one of the right eye and the left eye does not face the fixation target, and therefore, the line of sight of the eye E goes to a different place. In the ophthalmologic apparatus 10 according to the present embodiment, an examination is performed when the line of sight of the eye E to be inspected, either the right eye or the left eye, does not face the fixation target.

  FIG. 6 is a horizontal sectional view when the right eye ER is viewed from above. In FIG. 6, the left side corresponds to the front and the right side corresponds to the rear. The axis connecting the fixation target (fixation point) where the right subject's eye ER is fixating and the pupil center PC is the visual axis VX indicating where the right subject's eye ER is looking. On the other hand, an axis that exits from the pupil center PC in a direction perpendicular to the cornea Ec is the pupil axis PX that indicates the direction in which the right eye ER faces. Even in the eye E to be examined without a squint, the visual axis VX is slightly shifted to the nose side (downward in FIG. 6) with respect to the pupil axis PX. The angle between the visual axis VX and the pupil axis PX is called a lambda angle (indicated by λ in the figure). Although this lambda angle has individual differences even in the normal eye E without a squint, the average value is + 5 °. When performing a quantitative inspection of strabismus, it is necessary to take this lambda angle λ into account.

  Here, the visual axis VX and the pupil axis PX of the subject's eye E can be known from the position of a bright spot image Br (hereinafter, referred to as corneal reflection Br) based on the alignment light source 36a. The pupil axis PX of the eye E can be known from the position of the pupil center PC. A detailed calculation method of the visual axis VX and the pupil axis PX will be described later.

FIG. 8 is a diagram showing a positional relationship between the pupil P and the corneal reflex Br in various perspectives. As shown in FIG. 8, in the eye E to be examined having a perspective (the right eye ER in the example shown in FIG. 8), the position of the corneal reflection Br is shifted from the center of the pupil (hereinafter, this is referred to as pupil center PC). You can see that there is. Therefore, in the ophthalmologic apparatus 10 according to the present embodiment, a shift amount (distance d ₀ ) between the pupil center PC and the position of the corneal reflection Br is obtained, and the pupil axis PX and the optical axis of the measurement optical system 21 are calculated from the shift amount. obtains an angle theta of, based on eggplant lambda angle λ with the angle theta and pupillary axis PX and the visual axis VX, obtains an angle theta ₁ between visual axis VX and the optical axis, whereby a quantitative examination of perspective I do.

  In the ophthalmologic apparatus 10 according to the present embodiment, the deviation between the visual axis VX and the optical axis is obtained based on the Hirschberg method. In the Hirschberg method, the light source is placed at a distance of 33 cm from the subject's eye E, and the subject is instructed to fixate on the light source. The relationship between the PC and the position of the corneal reflection Br is measured, and an objective quantitative test is performed.

  In the ophthalmologic apparatus 10 according to the present embodiment, since the alignment light source 36a for providing the corneal reflection Br and the imaging device 31g of the observation system 31 are on the same optical axis, the anterior ocular segment image E 'captured by the imaging device 31g. By determining the pupil center PC from the above, and by determining the position of the corneal reflection Br in the anterior ocular segment image E ′, a quantitative inspection of objective strabismus according to the Hirschberg method can be performed.

  FIG. 9 is a diagram illustrating an example of an anterior ocular segment image E ′ captured by the image sensor 31g of the observation system 31. In FIG. 9, Br indicates a corneal reflex, Ep indicates a pupil image, PC indicates a pupil center of the pupil image Ep, and Ir indicates an iris image.

  FIG. 9A is an anterior eye image E ′ of the subject eye E without a perspective in a state where an instruction to fixate a specific viewpoint (fixation point) is given. As described above, in the case of the eye E having no perspective, the center of the pupil image Ep in the anterior ocular segment image E ', that is, the pupil center PC and the corneal reflection Br are at the same position.

  Next, FIG. 9B is an anterior eye image E ′ of the eye E to be inspected in a state where an instruction to fixate a specific viewpoint (fixation point) is given. The line of sight of the eye E to be inspected does not face the fixation point, and therefore, as described above, the position of the corneal reflection Br in the anterior ocular segment image E 'is shifted from the pupil center PC of the pupil image Ep.

  Hereinafter, the eye E without a squint in the state where the fixation point is instructed to be fixed is referred to as a fixation eye, and the squint eye E in the state where the fixation point is instructed to be fixed is similarly fixed eye. It may be called.

  According to the Hirschberg method, the ophthalmologic apparatus 10 according to the present embodiment presents a fixation target 33 cm ahead of the subject's eye E and instructs the subject to fixate the fixation target.

  Specifically, the control unit 27 displays a fixation target on the display 32a of the target projection system 32 of the ophthalmologic apparatus 10. Next, the measurement head control unit 27f of the control unit 27 rotates the measurement heads 16R and 16L about the eye rotation axes of the right eye ER and the left eye EL by the driving mechanism 15, and is 33 cm ahead of the eye E. An instruction is given to fixate the fixation target displayed at the fixation point PO (see FIG. 13). Thus, the right eye ER and the left eye EL are converged, and the fixation target is gazed at.

  At this time, the fixation target displayed on the display 32a simultaneously displays a rectangular fusion frame around the point-like fixation target from the viewpoint of enhancing the fusion of the right eye ER and the left eye EL. It may be done.

The rotation angles of the measuring heads 16R and 16L can be obtained as follows. As shown in FIG. 13, the presentation distance from the left subject's eye EL (or right subject's eye ER) to the presentation position of the fixation target is L (33 cm in the Hirschberg method), and the interpupillary distance of the subject is PD. Assuming that half of the interpupillary distance is hPD, the convergence angle の of the right eye ER or the left eye EL is given by the following equation (1).
The convergence angle Θ is the rotation angle of the measuring heads 16R, 16R.

In this state, the pupil center detection unit 27c and the corneal reflection position detection unit 27d of the control unit 27 of the ophthalmologic apparatus 10 according to the present embodiment determine the pupil center PC and the corneal reflection Br of the pupil image Ep in the anterior eye image E ′. And position. Then, the visual axis calculation unit 27e of the control unit 27 calculates the pupil center PC and the position of the corneal reflection Br based on the pupil center PC and the corneal reflection Br calculated by the pupil center detection unit 27c and the corneal reflection position detection unit 27d. shift amount calculated to obtain the angle theta between the optical axis of the pupillary axis PX and the measuring optical system 21, obtains the angle theta ₁ between visual axis VX and the optical axis.

  Further, the visual axis calculation unit 27e creates a schematic diagram showing the pupil center PC and the position of the corneal reflection Br in the anterior eye image E ', and displays this on the display unit 25b of the examiner controller 25.

  FIG. 10 shows an example of a schematic diagram displayed on the display unit 25b. FIG. 10A is a diagram showing a schematic view of the eye E to be examined, in which the left eye E is an external perspective (see FIG. 8), and FIG. 10B is an actual pupil P and corneal reflection Br of the eye E. FIG. In the schematic diagram shown in FIG. 10A, the inner circle C1 indicates the edge of the pupil P, and the outer circle C2 indicates the edge of the cornea Ec. The position of the corneal reflection Br is indicated by x. The position of the corneal reflection Br of the right subject's eye ER substantially matches the center of the pupil P (pupil center PC), while the position of the corneal reflection Br of the left subject's eye EL matches the center of the pupil P (pupil center PC). (It actually reaches the edge of the cornea Ec).

  The method of obtaining the position of the pupil center PC in the anterior eye image E ′ by the pupil center detection unit 27c may be appropriately selected from known methods. As an example, the pupil center detection unit 27c detects the edge of the pupil image Ep from the anterior eye image E ′ and calculates the boundary coordinates of the pupil image Ep. The edge of the pupil image Ep can be detected, for example, based on the difference in brightness between the pupil image Ep and the iris image Ir in the anterior eye image E ′.

Next, the pupil center detection unit 27c approximates the boundary coordinates of the pupil image Ep by ellipse, and calculates the center of the pupil approximate ellipse. First, the pupil center detection unit 27c obtains coefficients a, b, c, d, and h in the general formula of the ellipse shown in the following equation (2) by the least squares method from the boundary coordinates of the pupil image Ep.

Then, the pupil center detection unit 27c obtains the center coordinates of the approximate pupil ellipse from the coefficient in the general formula (2) of the ellipse according to the following equation (3).
The center coordinates of the approximate pupil ellipse obtained by equation (3) are the coordinates of the pupil center PC.

  Further, the corneal reflection position detection unit 27d obtains the position coordinates of the corneal reflection Br in the anterior ocular segment image E '. In the ophthalmologic apparatus 10 according to the present embodiment, since the alignment light source 36a is an infrared light, only the signal in the infrared light region is extracted from the output signal of the image sensor 31g, so that it is based on the reflected light from the alignment light source 36a. The position of the corneal reflection Br can be easily and accurately obtained.

  The visual axis calculation unit 27e calculates a shift amount of the position of the corneal reflection Br with respect to the position of the pupil center PC based on the calculated coordinates of the pupil center PC and the position coordinates of the corneal reflection Br.

For example, it is assumed that the position coordinates of the pupil center PC and the position coordinates of the corneal reflection Br shown in a schematic diagram as shown in FIG. In the example illustrated in FIG. 11, the left subject's eye EL has an outer perspective and a lower perspective. Then, the visual axis calculation unit 27e calculates the shift amount (distance d ₀ ) of the position of the corneal reflection Br with respect to the position of the pupil center PC as shown in FIG. It is determined as the direction shift amount dy.

  Next, the visual axis calculation unit 27e obtains an angle θ between the pupil axis PX and the optical axis of the measurement optical system 21. The calculation procedure will be described with reference to FIG. FIG. 12A shows the position of the luminescent spot Q of the alignment light source 36a in the eye E without a perspective, and FIG. 12B shows the position of the bright point Q of the eye E with a perspective. As described above, the position of the bright spot Q is obtained as the position of the corneal reflection Br in the anterior ocular segment image E '.

The angle θ is generally calculated based on the following equation (4), based on the radius of curvature r of the cornea (that is, the distance from the corneal curvature center R ₀ to the corneal vertex Ept), the position of the corneal vertex Ept, and the corneal reflection Br. It can be calculated using the distance d from the position.

  sin θ = d / r (4)

However, where the visual axis calculation unit 27e is a displacement amount d ₀ position of the corneal reflection Br with respect to the position of the pupil center PC _(described as the amount of deviation d ₀ if described without distinction dx and dy), cornea from the center of curvature _{R 0} by using the distance _{r 0} to the pupil center PC, based on the following equation (4-1), determining the angle theta. Thereby, the angle θ or the like can be calculated more efficiently based on the anterior eye image E ′.

sin θ = d ₀ / r ₀ (4-1)

The angle θ can be calculated by substituting the previously obtained distance d ₀ into the above equation (4-1). As the distance r ₀ , for example, an average value can be used. Specifically, the distance r ₀ is obtained by subtracting the distance r ′ between the corneal vertex Ept and the pupil center PC from the radius of curvature r of the cornea. When the average value of r = 7.7 mm and the average value of r ′ = 3.6 mm (however, the average value when the pupil center PC is the front surface of the crystalline lens), the distance r ₀ = (7.7-3. 6) mm = 4.1 mm.

Incidentally, each position of the pupil center PC and the corneal reflection Br is susceptible to refraction through the cornea, and there is individual difference in the distance r _0. Therefore, the distance d ₀ and the distance r ₀ are collected with respect to the pupil axis PX of the subject eye E having no perspective as shown in FIG. 12A and the pupil axis PX of the subject eye E facing various other directions. The distance r ₀ may be optimized based on these simultaneous equations. Alternatively, the distance r ₀ may be optimized from the measured value of the radius of curvature r of the cornea acquired by the kerato measurement.

Further, the angle θ can be calculated by the following equation (5) instead of the calculation procedure using the above (4) and (4-1). In the following equation (5), L ₀ indicates the distance from the corneal vertex Ept to the eye rotation point O, and D indicates the distance between the position of the corneal vertex Ept and the position of the eye rotation point O. The distance L ₀ from the corneal vertex Ept to cycloduction point O may be a predetermined value (for example, 13 mm is the average value). Alternatively, when the actual distance is known in measurement by another device, this value may be input. As the radius of curvature r of the cornea, it is possible to use an actually measured value obtained by keratometry. Further, the radius of curvature r of the cornea may be an average value (7.7 mm) as an initial value. Also in this case, the distance from the pupil center PC to the eye rotation point O is used instead of the distance L ₀ , and the position of the pupil center PC and the position of the eye rotation point O in the anterior eye image E ′ are used instead of the distance D. May be calculated using the distance to

sin θ = D / L ₀ (5)

  Further, as a method of calculating a different angle θ, for example, a displacement Δ of the corneal reflection Br (see FIG. 12B) can be used. The displacement Δ is determined by fixing the fixation target only to the eye E in which the displacement has been detected, obtaining each numerical value in the state of FIG. 12A, and calculating the displacement amount of the corneal reflection Br from the eye rotation point O. Can be represented.

The distance from the corneal vertex Ept to eyeball rotation point O and L _0, when the radius of curvature of the cornea is r, the displacement Δ of the corneal reflection Br shown in FIG. 12 (b), is expressed by the following equation (6) You. Again, it may be a distance L ₀ from the corneal vertex to the eyeball rotation point O predetermined value (for example, 13 mm is the average value). Alternatively, when the actual distance is known in measurement by another device, this value may be input. As the radius of curvature r of the cornea, an actual measurement value or an average value (7.7 mm) obtained by keratometry can be used.

Δ = (L ₀ −r) · sin θ (6)

Then, the point light source control unit 27g, in the eye E deviation amount d ₀ or displacement delta has been determined, moves the alignment light source 36a in a position to cancel the displacement amount d ₀ or displacement delta. In other words, after the alignment light source 36a is moved, the alignment by the alignment system 36 is performed again, and the point light source control unit 27g adjusts the alignment light source so that the pupil center PC and the position of the corneal reflection Br overlap in the anterior ocular segment image E '. 36a is moved on a plane perpendicular to the optical axis.

Here, it is considered to be conjugated to the light receiving surface of the alignment light source 36a and the imaging element 31 g, the deviation amount d ₀ or displacement movement of the alignment light source 36a by the point light source control unit 27g is the anterior segment image E 'delta Should be approximately equal.

(Operation of the ophthalmic device)
Next, an outline of the operation of the ophthalmologic apparatus 10 according to the present embodiment will be described with reference to the flowchart shown in FIG. 14 and FIG.

  The flowchart shown in FIG. 14 is for performing a strabismus examination by the ophthalmologic apparatus 10 after a strabismus is found in any of the eyes E to be examined.

  First, in step S1, the measuring head control unit 27f rotates the measuring head 16 so that the presenting position of the fixation target is 33 cm in accordance with the Hirschberg method. In this state, in step S2, the target projecting system 32 causes the display 32a to display a fixation target. In this state, the examiner instructs the subject to fixate on the fixation target, and causes the right eye ER and the left eye EL to converge.

In step S3, the alignment system 36 performs the XY alignment operation in a state where the subject is fixed on the fixation target. In step S4, the pupil center detection unit 27c detects the position of the pupil center PC in the anterior eye image E ', and the corneal reflection position detection unit 27d detects the position of the corneal reflection Br in the anterior eye image E'. . Then, the visual axis calculation unit 27e calculates the angle θ between the pupil axis PX and the optical axis, and based on the angle θ and the lambda angle λ between the pupil axis PX and the visual axis VX, the visual axis VX and the optical axis obtaining an angle theta ₁ with.

In step S5, the point light source control unit 27g moves the alignment light source 36a based on the angle θ calculated in step S4. In step S6, based on the position of the corneal reflection Br in the anterior ocular segment image E 'based on the alignment light source 36a moved in step S5 and the pupil center PC, the visual axis calculation unit 27e makes the pupil axis PX and the optical axis. angle theta, and recalculates the visual axis VX and the angle theta ₁ between the optical axis. Note that several points of the fixation point is presented to the subject performs subjective determination whether to fixation without problems, the angle theta ₁ may be corrected based on this subjective judgment. Further, these average correction values may be implemented.

In step S7, it is determined whether the angle theta ₁ calculated in step S6 is less than the threshold value is less than the threshold value programmed if it is determined that (YES in step S7) the process proceeds to step S8, is greater than or equal to the threshold value If it is determined (NO in step S7), the program returns to step S5, and the point light source control unit 27g further moves the alignment light source 36a. Here, although the threshold can be arbitrarily set, it is preferable to set in consideration of the lambda angle (+ 5 °) to the threshold angle theta ₁ at no perspective subject's eye E.

Since the angle theta ₁ which is calculated in step S7 is the amount of movement of the alignment light source 36a when it is determined to be less than the threshold is considered to be substantially the same as the displacement amount d ₀ or displacement Δ of the corneal reflection Br, The amount of movement of the alignment light source 36a may be a value of a quantitative inspection of strabismus, that is, a prism power.

In step S8, the rotary prisms 32A and 32B of the optotype projection system 32 are rotationally driven based on the angle θ ₁ formed between the visual axis VX and the optical axis calculated in step S4, or the moving amount of the alignment light source 36a. Rotary prisms 32A and 32B give the prism base direction and the prism power. In this state, the examiner performs a subjective test on the subject whether the fixation target presented by the target projecting system 32 is shifted (blurred) between the right subject's eye ER and the left subject's eye EL. (Step S9). Thereafter, the examiner instructs the rotary driving of the rotary prisms 32A and 32B using the examiner controller 25 and the like, finely adjusts the prism base direction and the prism power given by the rotary prisms 32A and 32B, and finally, The degree of obliqueness of the right eye ER or the left eye EL in a state where the fixation target is shifted and not detected is obtained as a prism base direction and a prism power.

  FIG. 15 is a diagram illustrating an example of a screen displayed on the display surface 25a of the examiner controller 25 of the ophthalmologic apparatus 10 according to the present embodiment. The screen shown in FIG. 15 is displayed after calculating the shift amount between the visual axis VX and the optical axis performed in steps S4 and S6 in the flowchart of FIG.

  The anterior eye image ER ′ of the right eye ER is displayed on the left of the center of the screen shown in FIG. 15, and the anterior eye image EL ′ of the left eye EL is displayed on the right. As described above, these anterior eye images ER ′ and EL ′ are captured by the image sensor 31 g of the observation system 31.

  In addition, below these anterior segment images ER ′ and EL ′, fixation targets 40R and 40L currently displayed by the display 32a of the target projection system 32 are displayed, respectively. Below the fixation targets 40R and 40L, schematic diagrams 41R and 41L, which are detection results of the pupil center detection unit 27c and the corneal reflection position detection unit 27d, respectively, are displayed.

(Effects of ophthalmic equipment)
In the ophthalmologic apparatus 10 according to the present embodiment configured as described above, the visual axis is determined based on the position of the pupil center PC and the position of the corneal reflection Br detected by the pupil center detection unit 27c and the corneal reflection position detection unit 27d, respectively. calculator 27e displacement shift amount d ₀ or luminescent spot image Br with the position of the pupil center PC as the amount of deviation of the visual axis VX right eye to be examined ER and the left eye to be examined EL and corneal reflection Br delta, more visual axis and it calculates the angle theta ₁ between VX and the optical axis.

The amount of deviation d ₀ or displacement Δ and the angle theta ₁ is a quantitative value of perspective of the eye E. Therefore, according to the ophthalmologic apparatus 10 of the present embodiment, it is possible to automatically and precisely perform the examination of the perspective and the oblique position of the eye E.

  Further, since the display unit 25b of the examiner controller 25 displays a schematic diagram showing the position of the pupil center and the corneal reflection in the anterior eye image E ′, the examiner can intuitively determine the degree of the perspective of the eye E to be examined. It can be easily grasped. Thereby, a qualitative inspection of the squint can be performed.

  Further, at a specific position in front of the right eye ER and the left eye EL, the measurement head control unit 27f is driven to fixate the fixation target by at least one of the right eye ER and the left eye EL. The measurement head 16 is rotated by the mechanism 15, and the pupil center detection unit 27c and the corneal reflection position detection unit 27d detect the pupil center and the position of the corneal reflection while the measurement head 16 is rotated by the measurement head control unit 27f. Therefore, a quantitative examination of the strabismus according to the Hirschberg method can be performed in a state where the right eye ER and the left eye EL are converged.

The measurement optical system 21 further includes an alignment light source 36a, an alignment system 36 that converts diffused light emitted from the alignment light source 36a into parallel light, and causes the parallel light to enter the right eye ER and the left eye EL. And a point light source driving unit 36c for moving the point light source on a plane orthogonal to the optical axis. The point light source control unit 27g moves the alignment light source 36a by the point light source driving unit 36c so that the position of the corneal reflection Br substantially matches the pupil center PC. Therefore, the degree of obliqueness of the eye E, that is, the amount of displacement d ₀ or displacement Δ of the corneal reflection Br, and / or the angle θ ₁ between the visual axis VX and the optical axis is calculated and confirmed based on the amount of movement of the alignment light source 36a. can do.

  The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to the embodiment and the example, and a design change that does not depart from the gist of the present invention. Are included in the present invention.

  As an example, the distance between the presenting position of the fixation target and the right eye or the left eye may be displayed on the screen of the display unit 25b of the examiner controller 25 (distance L in FIG. 13). FIG. 6 shows the relationship between the visual axis and the pupil axis based on the calculation result by the visual axis calculation unit 27e on the screen of the display unit 25b. As an example, the horizontal direction of the right eye and the left eye as shown in FIG. May be displayed such that the visual axis VX and the optical axis based on the actual measurement result are added to the sectional view of FIG.

  Further, in the ophthalmologic apparatus 10 according to the above-described embodiment, the quantitative inspection of the strabismus according to the Hirschberg method was performed. For this reason, the fixation target is arranged at a predetermined position 33 cm ahead of the eye E to be examined. That is, in the ophthalmologic apparatus 10 according to the embodiment, the quantitative examination of the strabismus in the proximal direction is performed. However, the display position of the fixation target is not limited to 33 cm in the above-described embodiment, and the fixation target may be arranged at another predetermined position, for example, a position at infinity, to perform a quantitative inspection of the perspective.

Br Cornea reflection E, ER, EL Eye to be inspected EL ', ER' Anterior eye image Ec Cornea Ep Pupil image P Pupil PC Pupil center PX Pupil axis R Bright point VX Visual axis Δ Shift amount 10 Ophthalmic apparatus 15 Driving mechanism (Drive unit )
16 Measuring head 21, 21R, 21L Measuring optical system 25 Examiner controller 25b Display unit 27 Control unit 27c Pupil center detecting unit 27d Corneal reflection position detecting unit 27e Visual axis calculating unit 27f Measurement head controlling unit 27g Point light source controlling unit 31 Observation System 31g Image sensor (image acquisition unit)
32 Target Projection System 36 Alignment System 36a Alignment Light Source 36c Point Light Source Drive

Claims (10)

A pair of measurement heads each storing a measurement optical system that acquires eye information of the right eye or the left eye of the subject,
An image acquisition unit that is provided in the measurement optical system and acquires an anterior eye image on the optical axis of the measurement optical system of the right eye or the left eye.
A pupil center detection unit that detects a pupil center of the right eye and the left eye from the anterior eye image of the right eye and the left eye obtained by the image acquisition unit,
Based on a point image obtained by forming light rays parallel to the optical axis incident on the right eye and the left eye from the measurement optical system in the right eye and the left eye, A corneal reflection position detection unit that detects the position of corneal reflection of the right eye and the left eye,
An ophthalmologic apparatus comprising: a visual axis calculation unit that calculates visual axes of the right eye and the left eye based on the pupil center and the position of the corneal reflex.   2. The ophthalmologic apparatus according to claim 1, further comprising a driving unit configured to rotate the measurement head around a rotation axis of an eyeball of the right eye or the left eye. 3. The measurement optical system includes a fixation target for causing a fixation of at least one line of sight of the right eye and the left eye on the optical axis of the measurement optical system. A target projection system to be presented to
The ophthalmologic apparatus performs the measurement by the driving unit such that at least one of the right eye and the left eye examines the fixation target at a specific position in front of the right eye and the left eye. Having a measuring head control unit for rotating the head,
3. The pupil center detection unit and the corneal reflection position detection unit detect the pupil center and the position of the corneal reflection while the measurement head is rotated by the measurement head control unit. An ophthalmologic apparatus according to item 1.   The ophthalmologic apparatus according to any one of claims 1 to 3, further comprising: a display unit that displays a schematic diagram showing a position of the pupil center and the corneal reflection in the anterior eye image.   The ophthalmologic apparatus according to claim 4, wherein the display unit displays a distance between the specific position and the right eye or the left eye.   The ophthalmologic apparatus according to claim 4, wherein the display unit displays a cross-sectional view in which the visual axis and the optical axis are written on a horizontal cross section of the right eye and the left eye. .   The visual axis calculation unit calculates an amount of deviation between the visual axis of at least one of the right eye and the left eye and the optical axis of the measurement optical system. An ophthalmologic apparatus according to any of the claims. The measurement optical system includes:
A point light source,
A parallel optical system that converts diffused light emitted from the point light source into parallel light and causes the right eye and the left eye to enter.
A point light source driving unit that moves the point light source on a plane orthogonal to the optical axis,
The ophthalmologic apparatus according to any one of claims 1 to 7, further comprising a point light source control unit that moves the point light source by the point light source driving unit so that the position of the corneal reflection substantially matches the center of the pupil. An ophthalmologic apparatus according to any of the claims.   The visual axis calculation unit is configured to determine a shift amount between the visual axis of at least one of the right eye and the left eye and the optical axis of the measurement optical system based on a moving amount of the point light source by the point light source control unit. The ophthalmologic apparatus according to claim 8, wherein the calculation is performed by:   2. The visual axis calculation unit calculates a prism base direction and a prism power of the right eye and the left eye based on the calculated visual axes of the right eye and the left eye. The ophthalmologic apparatus according to any one of claims 9 to 9.