Abstract:
An ophthalmologic examination apparatus is provided which is capable of performing a variety of ophthalmologic examinations with a low-cost configuration. An illuminating optical system for illuminating an eye fundus and an imaging optical system for imaging the illuminated eye fundus, which are both necessary in an ophthalmologic examination, are housed in a main unit. A plurality of attachment units is removably mounted to the main unit. Each of the attachment units is provided with a different ophthalmologic function such as a function for planarly or stereographically observing or photographing the imaged eye fundus, a function for emitting stimulating light on the eye fundus or a function for spectroscopically analyzing the eye fundus. Such an arrangement allows the ophthalmologic examination apparatus to perform various functions merely by selecting the attachment unit and mounting it to the main unit.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to an ophthalmologic examination apparatus having a plurality of ophthalmologic examination functions. 
         [0003]    2. Description of the Prior Art 
         [0004]    A variety of ophthalmologic examination apparatuses such as fundus cameras and perimeters are conventionally known. A cameras as disclosed in Japanese Patent No. 3359126 is, for example, provided with functions whereby an illuminated eye fundus is once imaged, then magnified and imaged again in the imaging region of a CCD in order to create images of the eye fundus having different magnification ratios. Similarly, a fundus cameras is also known from Japanese Laid-open Patent Application 1979-62691 wherein an illuminated eye fundus can be imaged, the resulting image can be magnified, and the image of the eye fundus can subsequently be divided in a position conjugate with the pupil for stereographical observation. 
         [0005]    A fundus cameras is also known from Japanese Laid-open Patent Application 1998-155743 wherein a photography unit for photographing an eye fundus is provided separately from a main unit that houses an illuminating optical system and a photographing optical system and an ocular lens is provided on the photography unit side. 
         [0006]    However, several problems arise in conventional ophthalmologic examination apparatuses. For example, the apparatuses are primarily intended for a single ophthalmologic examination wherein an eye fundus is observed or imaged, or a visual field is examined. This allows no various ophthalmologic examinations to be performed. Furthermore, the optical systems of apparatuses that perform a variety of ophthalmologic examinations are complex. 
         [0007]    Therefore, an object of the present invention is to provide an ophthalmologic examination apparatus that is capable of performing a variety of ophthalmologic examinations with an inexpensive arrangement. 
       SUMMARY OF THE INVENTION 
       [0008]    An ophthalmologic examination apparatus according to the present invention has a plurality of ophthalmologic examination functions and comprises a main unit for housing an illuminating optical system for illuminating a fundus of an eye to be examined and an imaging optical system for imaging the illuminated fundus of the eye to be examined, and a plurality of attachment units that are removably mounted to the main unit. Each of the attachment units is provided with a different ophthalmologic function to provide a different ophthalmologic function in accordance with the attachment unit mounted to the main unit. 
         [0009]    In the present invention, an illuminating optical system for illuminating an eye fundus and an imaging optical system for imaging the illuminated eye fundus, which are both necessary in an ophthalmologic examination, are housed in a main unit. A variety of ophthalmologic examination functions are given to an attachment unit that is mounted to the main unit via a mount. Therefore, a variety of ophthalmologic examinations can be performed merely by selecting the attachment unit and mounting it to the main unit. For example, the attachment unit is provided with a function for planarly or stereographically observing or photographing an imaged eye fundus, a function for emitting stimulating light onto the eye fundus, or a function for spectroscopically analyzing the eye fundus. Merely selecting and mounting it to the fundus camera, an ophthalmologic examination apparatus is provided that is capable of performing an ERG examination or a spectroscopic analysis examination or a visual field examination. Such an ophthalmologic examination apparatus shares most of elements or devices in the main unit and provides a multifunctional, remarkably low-cost examination apparatus. 
         [0010]    Further features of the invention, its nature and various advantages will be more apparent from the accompanying drawings and following detailed description of the invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]      FIG. 1  is an optical diagram showing a first embodiment of an ophthalmologic examination apparatus; 
           [0012]      FIG. 2  is an optical diagram showing a second embodiment of an ophthalmologic examination apparatus; 
           [0013]      FIG. 3  is an optical diagram showing a third embodiment of an ophthalmologic examination apparatus; 
           [0014]      FIG. 4  is an optical diagram showing a fourth embodiment of an ophthalmologic examination apparatus; 
           [0015]      FIG. 5  is an optical diagram showing a fifth embodiment of an ophthalmologic examination apparatus; 
           [0016]      FIG. 6  is an optical diagram showing a sixth embodiment of an ophthalmologic examination apparatus; and 
           [0017]      FIG. 7  is a perspective view showing an outer appearance of an ophthalmologic examination apparatus when an attachment unit has been mounted. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0018]    The present invention will now be described in detail with reference to the embodiments shown in the drawings. 
         [0019]    The present invention provides an illuminating optical system for illuminating an eye fundus, an imaging optical system for imaging the illuminated eye fundus and other optical systems in a main unit and provides ophthalmologic examination functions or devices to a separate attachment unit. The attachment unit is mounted on the main unit via a mount in order to perform a variety of ophthalmologic examination functions. 
         [0020]      FIG. 1  shows a first embodiment of the present invention in which the ophthalmologic examination apparatus is configured as a non-mydriatic fundus cameras. 
         [0021]    In the ophthalmologic examination apparatus shown in  FIG. 1 , an illuminating optical system for illuminating an eye fundus and an imaging optical system for imaging the illuminated eye fundus are provided to a main unit  10  of the apparatus. In the illuminating optical system, light emitted from a halogen lamp or another light source  11  together with light reflected by a concave mirror  12  forms into infrared light via a visible-cutting/infrared-transmitting filter  13 , passes through a stroboscope  14 , diffuses on a diffusion plate  15 , and illuminates a ring slit  16  disposed at a position conjugate with an anterior ocular segment (pupil)  1   b  of an eye  1  to be examined. Illuminating light from the ring slit  16  passes through a lens  17 , a black spot plate  18  for eliminating the reflection of an objective lens  22 , a half mirror  19  and a relay lens  20 ; reflects from an apertured total reflection mirror  21  having a central aperture; passes through the objective lens  22 ; impinges on the eye fundus  1   a  from the anterior ocular segment  1   b  of the eye  1  to be examined; and illuminates the eye fundus  1   a  with infrared light. 
         [0022]    Reflected light from the eye fundus  1   a  arrives via the objective lens  22  and passes through the aperture of the total reflection mirror  21 , a photography stop  31 , a focus lens  32  and an imaging lens  33 , then reflecting from a half mirror  34  and impinging on an infrared-transmitting/visible-reflecting mirror  36  via a field stop  35  disposed in a position conjugate with the eye fundus  1   a.  Infrared light transmitted through the infrared-transmitting/visible-reflecting mirror  36  reflects from a mirror  38 , passes through an imaging lens  37  and impinges on an imaging device  40  composed of an infrared-light-sensitive CCD or the like. A signal from the imaging device  40  is then input to a monitor  41 . 
         [0023]    Visible light reflected by the mirror  36  enters an attachment unit  50  via either of at least two types of variable-power lenses  47   a  and  47   b  and then reaches an imaging device  53  composed of a visible-light-sensitive CCD or the like that is housed in the attachment unit  50 . The attachment unit  50  is removably mounted to a mount  51  fixed to the main unit  10  adjacent to a position conjugate with the pupil. When a shutter  46  is manipulated, a shutter-manipulation signal is fed from the shutter  46  via a connector  52  to the imaging device  53  and a memory  54  for storing an image on the imaging device  53 . Power is also supplied to the imaging device  53  and memory  54  from the main unit  10  via the connector  52 . 
         [0024]    In such an imaging optical system, the position conjugate with the fundus  1   a  of the eye  1  to be examined is indicated by R, and the position conjugate with the anterior ocular segment (particularly the pupil) is indicated by P. The field stop  35  is disposed in a position conjugate with the eye fundus with respect to the optical system (first optical system) composed of the objective lens  22 , imaging lens  33 , and the like. Therefore, the image of the eye fundus produced by the optical system is formed adjacent to the field stop  35 . In addition, the imaging plane of the imaging device  40  is disposed in a position conjugate with the field stop  35  relative to the imaging lens  37 , and the imaging plane of the imaging device  53  is disposed in a position conjugate with the field stop  35  relative to the variable-power lenses  47   a  and  47   b  (second optical system). The eye fundus image on the field stop  35  is accordingly again created on the imaging devices  40  and  53  by the imaging lens  37  and the variable-power lenses  47   a  and  47   b.    
         [0025]    In such a configuration, the visible-cutting/infrared-transmitting filter  13  is inserted into the illuminating optical path. Therefore, the eye fundus is illuminated by infrared light and an image of the eye fundus is produced at the position of the field stop  35  by the objective lens  22 , focus lens  32 , and imaging lens  33 . The eye fundus image of the field stop  35  is transmitted by the infrared-transmitting/visible-reflecting mirror  36  and is again created on the imaging region of the imaging device  40  by the imaging lens  37 . Therefore, the image of the eye fundus is displayed as a black-and-white image on a monitor  41 . This allows the image of the eye fundus to be observed via the monitor  41  by the examiner. 
         [0026]    A focus-dot light source  30  is provided to the illuminating optical system. The light beam from the light source  30  impinges on the eye fundus  1   a  via the half mirror  19 . The position of the focus dot changes in accordance with the movement of the focus lens  32 , so that the examiner can observe the focus dot and bring the eye to be examined into focus. An anterior ocular segment lens  42  is inserted into the optical path at the initial stage of alignment. The examiner can accordingly verify the image of the anterior ocular segment  1   b  of the eye  1  to be examined using the monitor  41 . During alignment or focusing, an internal fixation lamp  43  is turned on, and the examiner can reliably perform alignment or focusing by bringing the attention of the person being examined to the fixation lamp. 
         [0027]    When the apparatus has been aligned, the shutter switch  46  is operated to produce a shutter operation signal, which is input to the imaging device  53  of the attachment unit  50  and to the memory  54  via the connector  52 . This enables the imaging device  53  to be activated to prepare an operation for capturing a still image of the eye fundus. A signal for initiating the emission of light (light regulating signal) is transmitted from the imaging device  53  to the stroboscope  14  in synchronization with the operation signal of the shutter switch  46 , thus enabling light to be emitted therefrom. The image of the eye fundus illuminated by light emitted from the stroboscope  14  is created at the position of the field stop  35  and is then recreated on the imaging region of the imaging device  53  by the variable-power lens  47   a  ( 47   b ). The imaging device  53  therefore captures the eye fundus image as a still image. 
         [0028]    The still image created by the imaging device  53  is saved in the memory  54  in the attachment unit  50 . The still image saved in the memory  54  is loaded into an external computer (not shown), displayed on the monitor  41 , or output to a printer (not shown). Alternatively, the memory  54  can itself be made into a cartridge and configured to be detachable from the attachment unit  50 . When the cartridge is introduced into another device, the contents of the memory can be read by this other device. 
         [0029]    The image of the eye fundus can also be produced with a variable photographic magnification ratio with the aid of the variable-power lenses  47   a,    47   b  disposed on the imaging optical system or with the aid of a zoom lens in place of the variable-power lenses. When the ratio is high, an expanded image of the eye fundus is captured without any image of the field stop  35 . When the ratio is low, an image of the eye fundus is captured together with the image of the field stop. For example, images that have been captured by setting the ratio to two values, retrieved from the memory  54  and displayed on the monitor  41  are schematically shown as symbols A and B in the upper right part of  FIG. 1 . The symbol A indicates an image of the eye fundus captured using a high magnification ratio, while the symbol B shows an image of the eye fundus captured using a low magnification ratio. It can be understood that the image of the field stop is also captured in the photography of low magnification ratio, as is shown by hatching in the periphery of the image B. The examiner can thereby determine an approximate capture ratio by viewing the appearance of the field stop in the image. 
         [0030]    On the other hand, the image received by the imaging device  40  disposed on the observation optical system receives no magnification of the variable-power lenses and the examiner can observe the black-and-white image at the same magnification ratio on the monitor  41 . To facilitate alignment, the magnification ratio of the optical system leading to the imaging device  40  may be set so that the imaging device can capture an image C having a wider region than the region captured by the imaging device  53 . Alignment using the imaging device  40  can thereby always be performed at a wide angle regardless of the magnification of the variable-power lens  47   a  ( 47   b ). 
         [0031]      FIG. 2  shows another embodiment. The same numeric symbols are applied to parts having the same or similar functions, and detailed descriptions thereof have accordingly been omitted. The ophthalmologic examination apparatus of this embodiment can be used as a mydriatic/non-mydriatic fundus cameras. The attachment unit  50  is provided with a monitor  55  to which the imaging device  53  and the memory  54  are connected. A signal from the imaging device  53  or a signal from the memory  54  is sent to the monitor  55 , and an image of the eye fundus can be displayed thereon. 
         [0032]    When the ophthalmologic examination apparatus is used as a non-mydriatic fundus cameras, a visible-cutting/infrared-transmitting filter  13  is inserted into the optical path and the examiner can observe the image of the eye fundus from the imaging device  40  in the same manner as in the first embodiment. Conversely, when used as a mydriatic fundus camera, the visible-cutting/infrared-transmitting filter  13  is retracted from the optical path, and the eye fundus is irradiated with visible light. The examiner therefore photographs the eye fundus using the imaging device  53  and observes the image of the eye fundus displayed on the monitor  55 . 
         [0033]    The image of the eye fundus captured as a still image by the imaging device  53 , under mydriatic or non-mydriatic mode, can be directly displayed on the monitor  55 , or can temporarily be stored in the memory  54 , retrieved from the memory and then displayed on the monitor  55 . 
         [0034]    In the second embodiment, the monitor  55  can be used in place of the monitor  41  of the main unit  10 . Alternatively, a monitor can be provided to the imaging device  53  or a monitor can be provided to the exterior of the attachment unit  50 . When the monitor  41  is used, the signals from the imaging device  53  and the memory  54  are directed to the monitor  41 , as indicated by the dashed line. 
         [0035]    The visible-cutting/infrared-transmitting filter  13  is inserted into or retracted from the optical path in accordance with mydriatic and non-mydriatic modes. The display of the images from the imaging devices  40  and  53  in both the modes is therefore automatically switched in accordance with the insertion and retract of the filter  13 . 
         [0036]    In the mydriatic mode, an infrared-cutting/visible-transmitting filter may be inserted into the optical path in place of the filter  13  in order to protect the eye to be examined. 
         [0037]      FIG. 3  shows a third embodiment in which the ophthalmologic examination apparatus is used as a mydriatic and non-mydriatic fundus cameras in the same manner as in  FIG. 2 . In  FIG. 3 , the same numeric symbols are applied to parts having functions that are the same as or similar to those of  FIGS. 1 and 2 , and detailed descriptions thereof have accordingly been omitted. An appearance of this embodiment is shown in  FIG. 7 . 
         [0038]    In this embodiment, an ocular function is provided to the attachment unit  50 , and a return mirror  60  is disposed in the optical path between the mount  51  and the imaging device  53 . When the return mirror  60  is in the indicated position, the image of the eye fundus reflected by the return mirror  60  is guided to an ocular lens  63  via a prism  61  and a lens  62 , and the image of the eye fundus can be observed via the ocular lens  63 . In this instance, a cap (light shielding means)  67  is mounted on a viewing hole  64  of an eyepiece in order to prevent stray light from entering when the device is not in use. The ocular lens  63  is placed near the monitor  55  of the second embodiment and is preferably disposed in a position that corresponds to the optical axis of the objective lens  22  to a degree whereby the monitor  41  in the main unit and the ocular lens will not greatly interfere with one another. The examiner can thereby readily perform alignment. 
         [0039]    A separate imaging device  65  composed of a CCD can be mounted to the viewing hole  64 . An image of the eye fundus from the imaging device  65  is sent to the monitor  41  via a connecter  66 , and can be displayed on the monitor  41 . A separate monitor may be used, but a less costly configuration can be achieved if the monitor  41  within the main unit  10  is used. 
         [0040]    In such a configuration, when the device is used as a non-mydriatic fundus cameras, a visible-cutting/infrared-transmitting filter  13  is inserted into the optical path during observation in the same manner as in the first and second embodiments, the image of the eye fundus from the imaging device  40  is displayed on the monitor  41 , and the examiner performs alignment and focusing while viewing the image of the eye fundus. Conversely, when the device is used as a mydriatic fundus cameras, the visible-cutting/infrared-transmitting filter  13  is withdrawn from the optical path, and the image of the eye fundus irradiated with visible light is reflected by the mirror  36 , transmitted by a variable-power lens, reflected by the return mirror  60  and observed via the ocular lens  63 . Instead of being observed via the ocular lens  63 , the image of the eye fundus can also be observed by mounting a CCD or another imaging device  65  on the viewing hole  64  and displaying the image of the eye fundus from the imaging device  65  on the monitor  41 . 
         [0041]    During image capture in both the non-mydriatic and mydriatic modes, the return mirror  60  is kept out of the optical path, the image of the eye fundus captured by the imaging device  53  is stored in the memory  54  and the stored image is exported to an external computer, displayed on the monitor  41 , or output to a printer. If the memory  54  can be removed, the contents of the memory can be read by another device once the memory has been introduced into the other machine. 
         [0042]    Advantages are realized with this embodiment in that direct eye observation via the ocular lens can be performed at the same magnification ratio as the image capture magnification ratio, and in that alignment by the imaging device  40  can always be performed at a wide angle regardless of the magnification used, as is the same with the first embodiment. 
         [0043]      FIG. 4  shows a still further embodiment in which the ophthalmologic examination apparatus is used as a mydriatic and non-mydriatic fundus cameras in the same manner as in  FIGS. 2 and 3 . In  FIG. 4 , the same numeric symbols are applied to parts having functions that are the same as or similar to those of  FIGS. 1 ,  2  and  3 , and detailed descriptions thereof have been omitted. 
         [0044]    In the embodiment of  FIG. 4 , the ophthalmologic examination apparatus has a function whereby an eye fundus can be photographed for stereographical observation. For this purpose, a plurality of apertures  31 ′ for dividing light beams is introduced into the optical path in proximity to the photography stop  31 . A dividing prism (optical path dividing means)  70  is additionally provided in the attachment unit  50 , and a plurality of aperture stops  71  is disposed directly before the dividing prism  70  in a position P conjugate with the pupil of the anterior ocular segment of the eye to be examined. An image of the eye fundus that has passed through the dividing prism  70  is received by an interpupillary adjustment prism  74  via a return mirror  72 , and is stereographically observed by the examiner via a binocular ocular unit composed of a right-eye ocular lens  75   a  and a left-eye ocular lens  75   b.  If the return mirror  72  is retracted from the optical path, the image of the eye fundus is captured by the imaging device  53  via lenses  73   a  and  73   b  for stereographical eye fundus observation. The imaging device  53  is mounted to the attachment unit  50  via an adapter  76 . An imaging device used exclusively for stereographical observation can also be mounted in place of this imaging device. A ring slit  16  disposed in the illuminating optical system in the main unit  10  can be exchanged with a ring slit  16 ′ for stereographical observation. The filter  13  is retracted from the optical path when the eye fundus is observed via a binocular ocular unit. In such a configuration, the eye fundus can be observed in a stereographical rather than planar fashion, and the eye fundus can therefore be scanned from multiple angles. 
         [0045]    In  FIG. 4 , the optical elements in the attachment unit  50  and the plurality of aperture  31 ′ are disposed in a direction orthogonal to the page space, but the representation in the drawing is shown from the direction orthogonal to the page space for the sake of simplicity. 
         [0046]    In the embodiment of  FIG. 4 , the plural aperture  31 ′, dividing prism  70 , plurality of aperture stops  71 , return mirror  72 , and lenses  73   a,    73   b  are disposed so that they are respectively introduced into the optical path in accordance with the selection of the variable-power lenses  47   a  and  47   b,  e.g. when variable-power lenses having a high magnification ratio have been selected. This allows a preferable configuration to be obtained because the attachment unit  50  does not need to be switched for stereographical photography. 
         [0047]    In the first through fourth embodiments, a position P that is conjugate with the pupil exists adjacent to the mount  51 . Therefore, an attachment unit having a normal photography function and an attachment unit having a stereographical photography function can readily be used. In addition, alignment by the monitor  41  during stereographical photography involves using a single screen as with normal photography (rather than using a split screen), and the focusing and working dots for normal photography can be used without modification for stereographical photography. Therefore, the examiner can perform alignment without difficulty. 
         [0048]      FIG. 5  shows a still further embodiment in which the ophthalmologic examination apparatus works as a perimeter. In  FIG. 5 , the same numeric symbols are applied to parts having functions that are the same as or similar to those of  FIGS. 1 through 4 , and detailed descriptions thereof have accordingly been omitted. 
         [0049]    In the embodiment of  FIG. 5 , an adjustable light-emitting diode  80  that emits visible light and infrared light and that can be moved manually or automatically in a plane orthogonal to the optical path is provided to the attachment unit  50  in a position R conjugate with the eye fundus in order to allow the apparatus to function as a perimeter. The light-emitting diode  80  functions as a projection target for an ERG (electroretinogram). When the shutter switch  46  is operated, the light-emitting diode  80  is caused by a controller  81  to light up and to emit visible light and infrared light. The visible light is transmitted by the variable-power lens  47   a  ( 47   b ), is reflect ed by the mirror  36  and is projected as stimulation light on the eye fundus  1   a  from the pupil  1   b  of the examined eye via the mirror  34 , lenses  33 ,  32 , the aperture of the total reflection mirror  21  and the objective lens  22 . An ERG electrode  82  is attached to the eye to be examined A signal from the electrode  82  is input to a computer  84  having a monitor  85  and an external storage device  86 . The computer  84  functions as a device for filing the eye fundus image and also produces a retinal potential diagram in accordance with the signals from the electrode  82 . The diagram produced is displayed on a monitor  85  and stored in the external storage device  86 . 
         [0050]    In this embodiment, the target created by the light-emitting diode  80  is transferred to the infrared light-sensitive imaging device  40 . Infrared light from the light-emitting diode  80  that has passed through the mirror  36  is reflected by the mirror  38  via a mirror  91 , prism  92 , and half mirror  93 , and is made incident on the imaging device  40  so as to be viewable on the monitor  41 . In this instance, the mirror  91  is disposed in a position conjugate with the field stop  35 , and the distance a between the field stop  35  and the mirror  36  is equal to the distance between the prism  92  and the mirror  93 . 
         [0051]    Visible light from the light-emitting diode  80  is reflected by the surface of the imaging lens  33  and returned as reflected light on the imaging device  40 . To prevent this, a filter  90  for transmitting infrared light and reflecting visible light is introduced between the infrared-transmitting/visible-reflecting mirror  36  and the half mirror  93 . The filter  90  has infrared transmitting characteristics, so that observation light impinges on the imaging device  40  without being cut by the filter  90 . 
         [0052]    In this embodiment, a liquid crystal display (LCD) device  87  may be disposed in place of the light-emitting diode  80  at a position R of the attachment unit  50  that is conjugate with the eye fundus. The liquid crystal display  87  is connected to the computer  84  via the controller  81 . Targets, letters, striped patterns and the like are displayed on the display device  87 . The targets and the like displayed are projected onto the fundus of the eye to be examined as stimulation light in the same manner as the target created by the light-emitting diode  80 . For example, the target is displayed at a variety of positions on the display device  87  by a computer each time the shutter switch  46  is operated or through a prescribed program. The target displayed is then projected onto the eye fundus and recognized by the person being examined. Upon recognition, the person being examined operates a response switch  83  to transmit a signal to the computer  84 , thus enabling the visual field of the person being examined to be measured. In addition, letters can be displayed on the display device  87 , and an examination can be performed in regard to whether the person being examined correctly recognizes the letters to examine weak eyesight. In this instance, a computer keyboard, touch panel, or other input means is provided to allow recognized letters to be input. 
         [0053]    Alignment must be performed in any ERG examinations that utilize a liquid crystal display device or a light-emitting diode. Alignment is performed by directing infrared light on the eye fundus, capturing the light reflected therefrom using the imaging device  40  and displaying the image of the eye fundus on the monitor  41 . In all instances, the shutter switch  46  that is operated after alignment is complete serves as a start switch for starting the examination. 
         [0054]      FIG. 6  shows a still further embodiment in which the ophthalmologic examination apparatus has a function for spectroscopically analyzing and examining an eye fundus. In  FIG. 6 , the same numeric symbols are applied to parts having functions that are the same as or similar to those of  FIGS. 1 through 5 , and detailed descriptions thereof have accordingly been omitted. 
         [0055]    In the embodiment of  FIG. 6 , a mirror  100  that is intermittently driven using a mirror-rotating device  101  composed of a stepping motor or the like is disposed in a position P in the attachment unit  50  conjugate with the pupil in order to spectroscopically analyze an image of the eye fundus. The image of the eye fundus reflected by the mirror  100  is transmitted by a lens  102 , reflected by a mirror  103 , passed through a slit  104 , is reflected by a mirror  105 , transmitted by a lens  106 , and made incident on a spectral element  107 . The spectral element  107  has the same configuration as the prism/grating/prism (PGP) described in Japanese Laid-open Patent Application No. 2002-224041. This element spectroscopically divides the image of the eye fundus slit by the slit  104  over a prescribed wavelength bandwidth in the longitudinal and perpendicular directions of the slit  104 . The spectroscopically divided image of the eye fundus passes through a lens  108  and impinges on an imaging device  109  composed of a CCD or the like. A spectral image of the slit image of the eye fundus is thus created and stored in a memory  110 . 
         [0056]    In such a configuration, when alignment is completed, the shutter switch  46  is operated, the light source  11  is turned on, and the eye fundus is illuminated while the mirror  100  is rotated in prescribed steps by the stepping motor. A line position of the image of the eye fundus created by the slit  104  changes in accordance with the rotation of the mirror, and slit images at the line positions of the eye fundus are captured by the imaging device  109  in accordance with the position of the mirror  100 . Spectral data of the slit images of the eye fundus at the line positions as captured by the imaging device  109  are loaded into the memory  110  in synchronization with the line positions of the eye fundus obtained from the mirror-rotating device  101 , stored for each line and spectroscopically analyzed by a spectral image analyzing device (not shown) 
         [0057]    Accordingly, an apparatus having the eye fundus image capture functions of the first and second embodiments can be converted to an apparatus that shares a large portion of the main unit while having a function for spectroscopically analyzing an image of the eye fundus. Such an apparatus can be obtained merely by installing an attachment unit that has a function for spectroscopically analyzing an image of the eye fundus.