JP5301908B2 - Eye refractive power measuring device - Google Patents

Description

  The present invention relates to an eye refractive power measuring apparatus that objectively measures the eye refractive power of a subject's eye.

  Conventionally, it has a projection optical system that projects a measurement index onto the fundus of the subject's eye and a light-receiving optical system that receives the fundus reflection light as a ring-like fundus reflection image on a two-dimensional image sensor, with the ring-shaped aperture positioned at the pupil conjugate position. An apparatus that measures eye refractive power based on a light receiving position of a ring image picked up by a two-dimensional light receiving element is known.

Further, in the eye refractive power measuring apparatus as described above, the refractive power for each meridian direction obtained when the ring-like fundus reflection image is approximated to an ellipse in order to obtain the spherical power, astigmatism power, and astigmatic axis angle of the eye to be examined. And a device that displays the standard deviation of the difference between the refractive power in each meridian direction obtained from an actual fundus reflection image as an irregular astigmatism (see Patent Document 1).
JP-A-9-276221

  By the way, in the apparatus as described above, when analyzing eye refraction measurement and irregular astigmatism for an eye to be examined such as keratoconus, which is one of irregular astigmatism, a ring imaged by a two-dimensional light receiving element. As an image, a ring image that is not significantly different from a normal astigmatic eye may be acquired. In such a case, it may be analyzed as a normal eye.

  In view of the above problems, an object of the present invention is to provide an eye refractive power measuring apparatus capable of accurately analyzing irregular astigmatism of an eye to be examined.

  In order to solve the above problems, the present invention is characterized by having the following configuration.

(1) A spot-like measurement light beam is projected from the center of the pupil of the subject's eye to the subject's eye fundus, and a fundus reflection light beam having a predetermined pattern shape is extracted from the periphery of the subject's eye pupil and received by the two-dimensional imaging device. Alternatively, by projecting a measurement light beam having a predetermined pattern shape from the periphery of the pupil of the eye to be examined, a predetermined pattern image is projected onto the fundus of the eye to be examined, and the fundus reflection light beam is received by the two-dimensional imaging device to cause eye refraction. A measurement optical system that images a force measurement pattern image with a two-dimensional image sensor;
A reflected light beam or a projected light beam having the predetermined pattern shape is eccentrically rotated on the eye pupil to be examined, having a light beam deflecting member disposed in the optical path of the measurement optical system and deviated from the conjugate position with the pupil. Rotating means for rotating the light beam deflecting member as described above,
Storage means for storing, as a measurement image, the pattern image based on the superposition of the fundus reflected light beam received by the two-dimensional imaging device via the light beam deflecting member rotated by the rotating means;
The shift of the light receiving position of the fundus reflected light beam in the two-dimensional image sensor when the measurement position on the eye pupil to be examined is changed by the rotating means is analyzed for each meridian direction of the measurement image stored in the storage means. Analyzing means for obtaining the refractive power of the eye to be examined and information relating to irregular astigmatism in the eye to be examined ;
Output means for outputting the result analyzed by the analysis means;
It is characterized by providing.
( 2 ) In the eye refractive power measuring apparatus according to claim 1 ,
The measurement optical system projects a spot-shaped measurement light beam from the center of the pupil of the subject's eye to the fundus of the subject's eye and picks it up as a ring-like fundus reflected light from the periphery of the subject's eye or receives the light around the subject's eye A ring-shaped image is projected onto the fundus of the subject's eye by projecting a ring-shaped measurement beam from the head, and the ring image for measuring eye refractive power is received by the two-dimensional image sensor by receiving the fundus reflection beam. An optical system,
The analysis means includes detection means for detecting the number of rings or the ring width for each meridian direction of the ring image stored in the storage means ,
The analyzing means detects whether or not a part having a plurality of rings is detected by the detecting means, or whether a part in which the width of the ring exceeds a predetermined width is detected. It is characterized by analyzing irregular astigmatism.
( 3 ) In the eye refractive power measurement apparatus according to claim 2 ,
The analyzing means detects whether or not a portion having a plurality of rings is detected in a ring region that is paired across a predetermined measurement center, or a portion in which the ring width exceeds a predetermined width. The analysis of the keratoconus of the eye to be examined is performed depending on whether or not a part having a plurality of rings is detected on the one hand and a part having a ring width exceeding a predetermined width is detected on the other hand. To do.
( 4 ) In the eye refractive power measurement apparatus according to claim 2 ,
The analysis means detects whether or not a part having a plurality of rings is detected in a ring region that is not paired across a predetermined measurement center, or a part in which the ring width exceeds a predetermined width. Depending on whether or not it has been performed, an analysis of irregular astigmatism of the eye to be examined is performed.
( 5 ) In the eye refractive power measurement device according to claim 2 ,
The analysis means includes a cataract eye determination means for analyzing a cataract of the eye to be examined based on the measurement image stored in the storage means,
It said analyzing means, and performs the analysis of the irregular astigmatism through screening by the cataract determining means.

  According to the present invention, it is possible to accurately analyze the irregular astigmatism of the eye to be examined.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is an external view of an eye refractive power measurement apparatus according to this embodiment. The measuring device is provided with a base 1, a face support unit 2 attached to the base 1, a moving base 3 movably provided on the base 1, and a movable base 3, which will be described later. A measuring unit 4 that houses the optical system is provided. The movable table 3 is moved on the base 1 in the left-right direction (X direction) and the front-rear direction (Z direction) by operating the joystick 5. Further, the measurement unit 4 is moved in the vertical direction (Y direction) by a drive mechanism including a motor or the like by rotating the rotary knob 5a. The moving table 3 is provided with a monitor 7 for displaying various information such as an observation image of the eye E and a measurement result, and a switch unit 8 in which switches for performing various settings are arranged.

  FIG. 2 is a schematic configuration diagram of an optical system and a control system in the eye refractive power measurement apparatus according to the present embodiment. The measurement optical system 10 includes a light projecting optical system 10a that projects a spot-like light beam from the center of the pupil of the eye to be examined to the fundus and a light receiving optical system 10b that extracts the reflected light from the periphery of the pupil in a ring shape. . The light projecting optical system 10a is a prism that is rotationally driven around the optical axis L1 by an infrared point light source 11, such as an LED or SLD, a relay lens 12, a hall mirror 13, and a drive unit 23, which are arranged on the measurement optical axis L1. 15. It consists of the objective lens 14 for a measurement, and is arrange | positioned toward the eye to be examined in this order. The light source 11 is conjugated with the fundus of the eye to be examined, and the hole portion of the Hall mirror 13 is conjugated with the pupil. The prism 15 is disposed at a position deviated from the position conjugate with the pupil of the eye E to be examined, and decenters the light beam passing therethrough with respect to the optical axis L1. A beam splitter 29, which is an optical path branching member, is disposed between the measurement objective lens 14 and the eye to be examined. The beam splitter 29 reflects the reflected light of the anterior eye portion of the eye to be observed to the observation optical system 50 and guides the light flux of the fixation target optical system 30 to the eye to be examined.

  The light receiving optical system 10b shares the measurement objective lens 14, the prism 15 and the hall mirror 13 of the light projecting optical system 10a, and the relay lens 16, the mirror 17 and the mirror 17 arranged in the optical path in the reflection direction of the hall mirror 13. A light receiving stop 18, a collimator lens 19, a ring lens 20, and an imaging element 22 that is a two-dimensional light receiving element such as a CCD are provided on the optical path in the reflection direction. The light receiving diaphragm 18 and the image sensor 22 have a conjugate relationship with the fundus of the eye to be examined. The output of the image sensor 22 is connected to the control unit 70 via the image memory 71.

  The ring lens 20 is provided in the light receiving optical system 10b so as to be in a conjugate position with the pupil of the eye to be examined, a lens portion in which a cylindrical lens is formed in a ring shape on a flat plate, and a coating for light shielding other than this lens portion. It is comprised from the light-shielding part which gave.

  On the optical axis L2 that is coaxial with the optical axis L1 by the beam splitter 29, an observation system objective lens 36, a half mirror 35, a light projection lens 33, a fixation target 32, and a visible light source 31 are sequentially arranged. The fixation target optical system 30 is constituted by the observation system objective lens 36. The light source 31 and the fixation target 32 perform clouding of the eye to be examined by moving in the direction of the optical axis L2. The light source 31 illuminates the fixation target 32, and the light flux from the fixation target 32 passes through the projection lens 33, the half mirror 35, and the objective lens 36, and then is reflected by the beam splitter 29 toward the eye to be examined. The fixation target 32 is fixed.

  Reference numeral 50 denotes an observation optical system. On the reflection side of the half mirror 35, a photographing lens 51 and a CCD camera 52 as an image pickup device are arranged. The output of the camera 52 is connected to the monitor 7 via the image processing unit 77. The anterior segment image of the eye to be examined is imaged on the image sensor surface of the camera 52 via the beam splitter 29, the objective lens 36, the half mirror 35, and the imaging lens 51, and the observation image is displayed on the monitor 7.

  Next, the operation of the apparatus having the above configuration will be described. During the measurement, the examiner observes the anterior segment image displayed on the monitor 7 and the corneal reflection image by an alignment index projection optical system (not shown), and operates the joystick 5 and the rotary knob 5a to measure the measurement unit 4 with respect to the subject's eye. Adjust the alignment. When the alignment is in an appropriate state, the measurement start switch 73 is pressed to start measurement. In addition, the fixation target by the fixation target optical system 30 is presented to the eye to be examined, and this is gazed at the eye to be examined.

  The control unit 70 turns on the light source 11 by the measurement start signal from the switch 73 and rotates the prism 15 at a high speed by the driving unit 23. The infrared light emitted from the light source 11 forms a spot-like point light source image on the fundus of the eye to be examined through the relay lens 12, the hall mirror 13, the prism 15, the objective lens 14, and the beam splitter 29. At this time, the pupil projection image (projected light beam on the pupil) of the hall portion of the hall mirror 13 is eccentrically rotated at high speed by the prism 15 rotating around the optical axis.

  The point light source image projected on the fundus is reflected and scattered, exits the eye to be examined, is condensed by the objective lens 14, and is received by the light receiving aperture 18 through the prism 15, the hall mirror 13, the relay lens 16, and the mirror 17 that rotate at high speed. The light is condensed again at the position, and the collimator lens 19 and the ring lens 20 form an image on the image sensor 22 in a ring shape. Here, since the prism 15 is disposed in the common optical path of the light projecting optical path and the light receiving optical path, the reflected light beam from the fundus passes through the same prism 15 as the light projecting optical system 10a. Reverse scanning is performed as if the projected light beam and reflected light beam (received light beam) are not decentered on the pupil.

  At this time, preliminary measurement of eye refractive power is first performed, and the light source 31 and the fixation target plate 32 are moved in the direction of the optical axis L2 based on the result of the preliminary measurement. It is done. Thereafter, the eye refractive power is measured for the eye to be inspected with cloud fog.

  FIG. 3 is a diagram for explaining the positional change of the projected light beam and the received light beam on the pupil. As shown in FIGS. 3A to 3D, the light projecting light beam 100 and the light receiving light beam 101 on the pupil rotate eccentrically around the center of the pupil Pu where the measurement optical axis L1 is positioned while maintaining the mutual positional relationship. To do. If the moment is captured, the fundus reflection image on the image sensor 22 is a ring image corresponding to each measurement position. By rotating the prism 15 at a high speed in a cycle shorter than the accumulation time of the image sensor 22, the image sensor 22. Can be detected as an integrated ring image. For the detailed configuration of this configuration, refer to Japanese Patent Application Laid-Open No. 2005-185523 filed by the present applicant.

  Here, the output signal from the image sensor 22 is stored in the image memory 71 as image data (measurement image). Thereafter, the control unit 70 specifies the position of the ring image in each meridian direction based on the measurement image stored in the image memory 71, and uses the least square method or the like based on the specified image position of the ring image. Approximate an ellipse. And the control part 70 calculates | requires the refraction error of each meridian direction from the approximate ellipse shape, and based on this, the eye refraction value of the eye to be examined, S (spherical power), C (column surface power), A (astigmatic axis) Each value of (angle) is obtained by calculation. The measurement result is displayed on the monitor 7.

  Here, as described above, when the prism 15 at a position deviating from the conjugate position with the pupil is rotated, the received light beam taken out in a ring shape on the eye pupil is eccentrically rotated with respect to the pupil center. Thus, the measurement position on the eye pupil changes as needed. As a result, the measurement range on the pupil when the prism 15 is rotated at a high speed is as shown in FIG. (Refer to the hatching area S) Therefore, the ring image obtained by being imaged on the image sensor 22 and accumulated for a predetermined time is a refractive characteristic of the eye to be examined in the moving range of the ring image obtained by at least one rotation of the prism 15. The light is received in a state where it is included.

  Here, the ring image stored in the image memory 71 can be considered as data obtained by averaging the refraction characteristics of the entire eye cornea and the entire crystalline lens in the moving range of the ring image as described above. Further, the ring image information for each meridian direction of the ring image can be considered as data obtained by averaging the refraction characteristics in a predetermined measurement region formed by the change in the measurement position. For example, the ring image information in the meridian direction 90 ° can be said to be data obtained by averaging the refraction characteristics in the measurement region S1 (see FIG. 4) on the eye pupil to be examined. Accordingly, in the obtained ring image, the ring image information such as the ring width, the number of rings, and the luminance level changes in whole or in part (for each meridian direction) according to the refractive power distribution of the eye to be examined.

  5 to 8 are diagrams showing examples of ring images obtained on the light receiving element for various eye types with different states. FIG. 5 is a schematic diagram of a ring image obtained when the subject's eye is a normal eye, and FIG. 6 is a schematic diagram of a ring image obtained when the translucent part of the subject's eye has turbidity (a cataract eye). 7 is a schematic diagram of a ring image obtained when the eye to be examined is considered to be keratoconus or suspected, and FIG. 8 is a schematic diagram of a ring image obtained when the eye to be examined has irregular astigmatism.

  Here, the ring image of the normal eye as shown in FIG. 5 is generally bright (the peak value of the luminance signal is large), and the ring width (thickness) is thin (sharp) over the entire circumference of the ring image. As the ring image of the cataract eye as shown in FIG. 6 scatters the measurement light by the turbid part, compared with the ring image of the normal eye as shown in FIG. The ring image becomes dark (the peak value of the luminance signal is small), and the ring width becomes thick.

  On the other hand, in the case of the ring image of the keratoconic eye as shown in FIG. 7A, the ring image is bright overall, but the measurement center O (the intersection position between the measurement optical axis L1 and the imaging surface of the imaging element 22, the ring center). There are portions where two rings are imaged in a region facing each other across the center of gravity of the ring, such as the center of gravity of the ring, which is a reference center position for acquiring ring image information in each meridian direction. In the case of FIG. 7B, the ring image is generally bright, but there are portions where the ring widths are thicker in regions facing each other across the measurement center O. Note that the keratoconus in the case of FIG. 7 is a corneal shape in which the corneal center of the eye to be examined is the apex of the cone and the corneal shape in the vertical direction is substantially conical, and the left-right direction of the eye cornea is substantially spherical. It is a schematic diagram. In this case, in a region facing the measurement center O, there may be a portion where two rings are captured on the one hand and a portion where the ring image is thick on the other hand. When the cornea center of the eye to be examined is the apex of the cone and the corneal shape in the vertical and horizontal directions is substantially conical, there may be two ring images in all meridian directions.

  In addition, in the case of a ring image of irregular astigmatism (illegal astigmatism other than keratoconus) as shown in FIG. 8A, the ring image is bright overall, but the ring width is wide in a region that does not face the measurement center. (There is a possibility that two rings are imaged). In addition, in the case of a ring image with irregular astigmatism as shown in FIG. 8B, the ring image is bright overall, but there is a portion where the ring width is thick in one region (two rings are May be imaged).

  Here, when the ring image information for each meridian direction is examined from the ring images of FIGS. 5 to 8 described above, the ring image in each meridian direction is one and the ring width is narrow as in the normal eye. Even if the measurement position changes due to the rotation of the prism 25, the amount of change in the refractive characteristics of the eye to be examined is small. In addition, as in the case of a severe keratoconus, there are two ring images in each meridian direction. This means that when the measurement position is changed by the rotation of the prism 25, the refractive characteristics of the eye to be examined rapidly in the meridian direction. It shows that there was a part that changed. Here, the ring width in each meridian direction is large even when the luminance signal of the ring image is high, as in the case of a light keratoconus, when the measurement position is changed by the rotation of the prism 25. It shows that the refractive characteristics of the eye to be examined change gently with respect to the direction.

  Hereinafter, by analyzing the measurement image stored in the image memory 71, information on the cornea or / and the crystalline lens of the eye other than refractive power (for example, whether there is irregular astigmatism in the eye to be examined or whether there is a keratoconus). A specific example of the method will be described with reference to the flowchart of FIG. First, the case where there is no kerato / topo information will be described. Here, the control unit 70 analyzes the keratoconus and irregular astigmatism of the eye to be inspected based on the ring image and the ring image information for each meridian direction of the ring image. More specifically, when the measurement position on the eye pupil to be examined is changed by the rotation of the prism 15, the control unit 70 receives the ring image in each meridian direction due to the difference in refractive power of the eye to be examined at each measurement position. A position shift is detected, and it is determined whether or not the light receiving position shift satisfies a predetermined allowable range.

  The control unit 70 detects the peak of the luminance signal of the ring image stored in the image memory 71 (the portion where the luminance signal turns from increasing to decreasing) for each meridian direction, and determines the peak value and the number of peaks of the luminance signal for each meridian direction. Detect for each meridian direction. Further, the ring width of the ring image stored in the image memory 71 is detected for each meridian direction. The ring width can be detected from, for example, the half-value width with respect to the peak of the luminance signal for each meridian direction.

  And the control part 70 is the ring width for every meridian direction where the average value in the ring perimeter of the calculated peak value is below a predetermined level (for example, half the peak value of normal eyes). If it is determined that more than one-half of the ring image has a ring width (for example, a ring width that is three times that of normal eyes) or more (for example, a ring width that is three times larger than that of normal eyes) continuously, suspected cataract Analyzes that there is turbidity in the subject eye transparent body, and displays the analysis result on the monitor 7. When two ring images are detected, the ring width of each ring image is detected and a determination is made for each ring width.

  On the other hand, when the determination conditions for the cataract are not satisfied, the control unit 70 proceeds to the irregular astigmatism or keratoconus analysis (determination) for the eye to be examined. Here, the control unit 70 divides the ring image at predetermined angles (for example, 8 divisions every 45 degrees), and in each divided area, whether or not a portion where the ring width exceeds the predetermined width is detected. It is determined whether or not a portion having a plurality of ring images has been detected. Whether or not a portion having a plurality of ring images has been detected is determined by the number of luminance signal peaks in each meridian direction.

  More specifically, as shown in FIG. 10, the control unit 70 divides the ring image at intervals of 45 degrees with the measurement center O as a reference. In this case, the ring image received on the image sensor 22 is divided into 45-degree intervals as the first ring region E1 to the eighth ring region E8 in order from 0 °. Thereby, ring image information (ring width, number of peaks, etc.) detected for each meridian direction is divided for each region.

  The control unit 70 determines for each ring region E1 to E8 whether or not there is a portion where the ring width exceeds a predetermined level (for example, a ring width that is twice or more that of normal eyes) or whether there is a portion having two peaks. Here, the control unit 70 detects a portion having two peaks in each of the ring regions (E1 and E5, E2 and E6, E3 and E7, E4 and E8) that are paired across the measurement center O. Or when a portion having two peaks is detected in one ring region and a portion where the ring width exceeds a predetermined level is detected in the other ring region, the control unit 70 analyzes the eye to be examined as a keratoconus, A message is displayed on the monitor 7. Further, the control unit 70 analyzes that the eye to be examined is suspected to be a keratoconus when each of the ring regions that are paired across the measurement center O detects a portion where the ring width exceeds a predetermined level. Display on the monitor 7.

  Further, the control unit 70 detects a portion having two peaks or a portion having a ring width exceeding a predetermined level in each of the ring regions (for example, E2 and E4) that are not paired across the measurement center O. When a portion having two peaks or a portion having a ring width exceeding a predetermined level is detected in a certain ring region, the eye to be examined is analyzed as irregular astigmatism, and this is displayed on the monitor 7.

  Further, the controller 70 does not detect a portion where the ring width exceeds a predetermined level or a portion having two peaks in each of the ring regions E1 to E8, that is, the ring image information in each ring region is within the normal range. In this case, it is analyzed that the eye to be examined is a normal eye, and that effect is displayed on the monitor 7. Even in a normal eye, the refractive characteristics at each measurement position when the measurement position is changed by the rotation of the prism 14 change strictly speaking, but within a range of 0.25D or 0.5D in terms of diopter. The level is within the range, and the deviation of the light receiving position of the ring image in each meridian direction is small.

  When the analysis result is displayed on the monitor 7 as described above, it is preferable to display the analysis result together with the eye refractive power value of the eye to be calculated calculated based on the ring image stored in the image memory 71. When the analysis result is displayed on the monitor 7, the keratoconus can be considered as one of irregular astigmatism. Therefore, when the control unit 70 has analyzed that the keratoconus or the keratoconus is suspected in the above analysis, You may make it display the message that the to-be-tested eye is irregular astigmatism on the monitor 7 (including the meaning of a display of suspected irregular astigmatism).

  If it is set as the above structures, the analysis of the keratoconus or irregular astigmatism of the eye to be examined can be accurately performed in a wide range. In the above configuration, measurement optics for measuring the corneal shape of the eye to be examined by projecting a corneal shape measurement index (for example, a ring index) on the eye cornea and capturing an image of the index projected on the eye cornea. A system may be provided. In this case, the control unit 70 analyzes keratoconus or irregular astigmatism of the eye to be examined based on the captured index image. More specifically, the standard deviation of the difference between the corneal refractive power for each meridian direction obtained by approximating the corneal shape measurement index image to an ellipse and the corneal refractive power for each meridian direction obtained from the actual index image To analyze irregular astigmatism or keratoconus.

  Then, the control unit 70 determines that the determination result determined based on the corneal index image is a normal eye, while the determination result determined based on the ring image for eye refractive power measurement as described above is irregular astigmatism. Or when it determines with a keratoconus, it determines with the suspicion of astigmatism in the crystalline lens of the eye to be examined. If the analysis result based on the corneal index image and the ring image is analyzed to be both abnormal, the analysis result is displayed on the monitor 7 assuming that the cornea of the eye to be examined is abnormal (kerato / top information in FIG. 9). See yes).

  In the above description, a spot-shaped measurement light beam is projected from the center of the subject's eye pupil to the subject's eye fundus, and a ring-like fundus reflected light beam is extracted from the periphery of the subject's eye pupil and received by the two-dimensional imaging device. The measurement optical system is not limited to this, but a projection optical system that projects a ring image on the fundus of the subject eye by projecting a ring-shaped measurement light beam from the periphery of the eye pupil to be examined, and the eye of the subject eye In a measurement optical system (for example, see Japanese Patent Application Laid-Open No. 1-129830) having a light receiving optical system for causing a two-dimensional imaging device to receive a ring image projected on the fundus, a ring-shaped projected light beam is projected on the eye pupil The present invention can be applied even in a configuration in which a light beam deflecting member for deflecting the measurement light beam so as to be eccentrically rotated is provided in the common optical path of the projection optical system and the light receiving optical system and the light beam deflecting member is rotationally driven. Ah .

  Further, the light beam passing around the pupil of the eye to be examined is not limited to the ring-shaped light beam, and instead of the ring lens 20 in the above description, every predetermined meridian direction centered on the measurement optical axis L1 (for example, 45 The present invention can be applied even to a configuration in which eight spot images are received on the two-dimensional image pickup device by arranging the circular holes and the small lenses at a time. That is, any configuration may be used as long as the eye refractive power of the eye to be examined is measured by receiving a pattern image having a predetermined pattern shape on the two-dimensional imaging device.

  When a light beam deflecting member such as the prism 25 is disposed in the light projecting optical system and the light receiving optical system, a light beam deflecting member is disposed in each of the light projecting optical system 10a and the light receiving optical system 10b. It may be configured to be rotated in synchronization with each measurement optical axis. In this case, a driving unit for rotating each optical deflection member is provided, and the optical deflection member is driven to rotate synchronously so that the deflection directions of the optical deflection members coincide with each other (for details, refer to Japanese Patent Application Laid-Open No. 2005-185523).

It is an external view of the eye refractive power measuring apparatus which concerns on this embodiment. It is a schematic block diagram of the optical system and control system in the eye refractive power measuring apparatus which concerns on this embodiment. It is a figure explaining the position change of the received light beam on a pupil. It is a figure which shows the measurement range on a to-be-examined eye pupil. It is a schematic diagram of a ring image obtained when the eye to be examined is a normal eye. It is a schematic diagram of the ring image obtained when there is turbidity (cataract eye) in the translucent part of the eye to be examined. It is a schematic diagram of a ring image obtained when it is assumed that the eye to be examined is keratoconus or suspected. It is a schematic diagram of a ring image obtained when the eye to be examined is irregular astigmatism. It is a figure shown about the specific example of the method of acquiring the information of the cornea or / and the crystalline lens of the eye other than refractive power. It is a figure at the time of dividing the ring image memorize | stored in the memory | storage part into 8 parts.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Measurement optical system 10a Light projection optical system 10b Light reception optical system 15 Prism 22 Two-dimensional image sensor 23 Drive part 70 Control part 71 Image memory

Claims (5)

A spot-like measurement light beam is projected from the center of the pupil of the subject's eye to the subject's eye fundus, and a fundus reflection light beam having a predetermined pattern shape is extracted from the periphery of the subject's eye pupil and received by the two-dimensional imaging device, or the eye to be examined Projecting a predetermined pattern image on the fundus of the subject's eye by projecting a measurement light beam having a predetermined pattern shape from the periphery of the pupil, and making the two-dimensional image sensor receive the reflected light from the fundus for eye refractive power measurement A measurement optical system that captures a pattern image with a two-dimensional image sensor;
A reflected light beam or a projected light beam having the predetermined pattern shape is eccentrically rotated on the eye pupil to be examined, having a light beam deflecting member disposed in the optical path of the measurement optical system and deviated from the conjugate position with the pupil. Rotating means for rotating the light beam deflecting member as described above,
Storage means for storing, as a measurement image, the pattern image based on the superposition of the fundus reflected light beam received by the two-dimensional imaging device via the light beam deflecting member rotated by the rotating means;
The shift of the light receiving position of the fundus reflected light beam in the two-dimensional image sensor when the measurement position on the eye pupil to be examined is changed by the rotating means is analyzed for each meridian direction of the measurement image stored in the storage means. Analyzing means for obtaining the refractive power of the eye to be examined and information relating to irregular astigmatism in the eye to be examined ;
And an output means for outputting a result analyzed by the analysis means. In the eye refractive power measuring device according to claim 1 ,
The measurement optical system projects a spot-shaped measurement light beam from the center of the pupil of the subject's eye to the fundus of the subject's eye and picks it up as a ring-like fundus reflected light from the periphery of the subject's eye or receives the light around the subject's eye A ring-shaped image is projected onto the fundus of the subject's eye by projecting a ring-shaped measurement beam from the head, and the ring image for measuring eye refractive power is received by the two-dimensional image sensor by receiving the fundus reflection beam. An optical system,
The analysis means includes detection means for detecting the number of rings or the ring width for each meridian direction of the ring image stored in the storage means ,
The analyzing means detects whether or not a part having a plurality of rings is detected by the detecting means, or whether a part in which the width of the ring exceeds a predetermined width is detected. An eye refractive power measuring device that performs analysis on irregular astigmatism. In the eye refractive power measuring device according to claim 2 ,
The analyzing means detects whether or not a portion having a plurality of rings is detected in a ring region that is paired across a predetermined measurement center, or a portion in which the ring width exceeds a predetermined width. The analysis of the keratoconus of the eye to be examined is performed depending on whether or not a part having a plurality of rings is detected on the one hand and a part having a ring width exceeding a predetermined width is detected on the other hand. Eye refractive power measuring device. In the eye refractive power measuring device according to claim 2 ,
The analysis means detects whether or not a part having a plurality of rings is detected in a ring region that is not paired across a predetermined measurement center, or a part in which the ring width exceeds a predetermined width. An eye refractive power measurement apparatus that performs an analysis on irregular astigmatism of an eye to be examined depending on whether or not it is performed. In the eye refractive power measuring device according to claim 2 ,
The analysis means includes a cataract eye determination means for analyzing a cataract of the eye to be examined based on the measurement image stored in the storage means,
Said analysis means, said cataract determining means eye refractive power measuring apparatus, characterized in that through the screening analyzes for the irregular astigmatism due.