JP5092120B2 - Eye movement measurement device - Google Patents

Description

  The present invention relates to an eye movement measuring apparatus for measuring eye movement, and more particularly to an eye movement measuring apparatus capable of measuring eye movement by imaging a conjunctival and / or scleral blood vessel pattern of the eye.

  Conventional methods for measuring eye movement include an ocular myoelectric measurement method, a corneal reflection measurement method, a pupil center position measurement method, and an iris position measurement method. The ocular myoelectric measurement method is centered on the measurement of the rotation speed, relative rotation position, and the like of the eyeball, and the measurement accuracy is low because an accumulation error occurs in the measurement of the absolute position of the eyeball. The corneal reflection measurement method is easily affected by individual differences depending on the surface condition of the cornea, which also has a low measurement accuracy. The pupil center position measurement method has not only a problem of accuracy but also a problem of obstructing a part of the line of sight during measurement. In addition, conventional eye movement measurement devices other than the iris position measurement method cannot measure the rotation angle of the eyeball around the visual axis. Furthermore, in the iris position measurement method, the pupil size differs depending on the intensity of light and mental state, and this has a problem of affecting measurement accuracy. Furthermore, the measurement error in the current commercial apparatus is about 0.5 ° even in the best state. Therefore, for example, when it is used to measure the position of the line of sight, the error becomes larger as the target becomes farther away.

  In addition, there is a technique that takes a fundus image, extracts a pattern presented on the eyeball from the fundus image, calculates an eyeball rotation angle, and measures eye movement (Patent Document 1).

JP-A-4-156818

  However, the conventional eye movement measuring device has a low measurement accuracy as described above, and it has been difficult to measure a three-degree-of-freedom rotational movement.

  In addition, it is known that the eyeball is moving so fine that it cannot be seen with the naked eye, such as involuntary eye movement. Fixation micromotion always vibrates at a high frequency (up to 90 Hz) even while the eyeball is fixing the target. As described above, since the movement speed of eye movement of the eyeball is fast, there is no apparatus that can measure the eye movement even when using the various measurement methods described above and the technique disclosed in Patent Document 1. For this reason, it has been impossible to measure the position of the eyeball more accurately. Since most conventional eye movement measurement devices using a camera use a camera that captures images at 30 to 60 frames / second, it has been impossible to capture fixation micromotion with a high movement speed. Therefore, there has been no apparatus capable of accurately measuring eye movements such as fixation micromotion at a high speed and an extremely short movement distance.

  Furthermore, since eye movements always exist in this way, the conjunctiva of the eyeball and the blood vessels of the sclera cannot be recognized.

  In addition, the technique disclosed in Patent Document 1 has a problem of obstructing a part of the line of sight when photographing a fundus image, a problem of real-time measurement, a problem of measuring an eyeball position when gazing at an arbitrary target, and the like. Was difficult.

  In view of such circumstances, the present invention intends to provide an eye movement measurement device capable of measuring the movement of the eyeball by imaging the blood vessel pattern of the conjunctiva and / or sclera of the eyeball.

  In order to achieve the above-described object of the present invention, an eye movement measuring apparatus according to the present invention is configured to capture an imaging area of at least 200 μm to 5000 μm square with a resolution of 1 μm to 10 μm, so as to be able to image the fixation eye movement of the eyeball. An imaging means capable of imaging at a shutter speed of 01 seconds or faster and / or 100 frames / second or more; an adjusting means for adjusting the position of the imaging area of the imaging means; and a blood vessel pattern of the conjunctiva and / or sclera of the eyeball An image processing unit that performs image processing on an image captured by the imaging unit so that the image can be recognized and tracked, a measuring unit that measures eye movement using the image processed by the image processing unit, and an image captured by the imaging unit Display means for displaying an image to be processed or an image processed by the image processing means or a measurement result by the measuring means.

  Here, the measuring means extracts the conjunctival and / or scleral blood vessel pattern from the image to be processed, and calculates the rotation angle of the eyeball from the movement position of the conjunctival and / or scleral blood vessel pattern. Anything is fine.

  In addition, at least two eye movement measuring devices are used in synchronization, and a three-degree-of-freedom rotational position of the eyeball is calculated by measuring a movement of the eyeball by imaging a different area with respect to one eyeball. May be.

  Furthermore, it has wide-angle imaging means capable of imaging the entire eyeball, and the image processing means performs image processing and adjustment of the wide-angle image captured by the wide-angle imaging means so that the position of the conjunctiva and / or sclera of the eyeball can be searched. The means may be one that manually or automatically adjusts the position of the imaging area according to the position of the conjunctiva and / or sclera using a wide-angle image processed by the image processing means.

  The display means may display mark means indicating the imaging area of the imaging means on the wide-angle image captured by the wide-angle imaging means.

  Further, the adjusting means is configured to sequentially move the position of the imaging area of the imaging means so that each part of the conjunctiva and / or sclera of the eyeball can be sequentially imaged, and the image processing means is configured to connect the sequentially captured images. You may do it.

  In addition, the image processing means sequentially extracts feature areas of images that are picked up sequentially, searches for the same feature area in the subsequent image, and if there is no same feature area, extracts another new feature area and performs the same in the subsequent image. The feature area may be searched, and the measuring unit may be configured to measure the rotation of the eyeball based on the searched feature area.

  Furthermore, an authentication unit that compares and authenticates a past image and a current image may be provided.

  In addition, the eye movement measuring device is synchronized to measure both eyeballs by using at least two, and the measuring means calculates the rotation angle of both eyeballs when gazing at the target at a known position as a reference angle. The position of the line of sight may be measured from the difference between the rotation angle of both eyeballs and the reference angle when gazing at the unknown position.

  Furthermore, you may make it have a mirror arrange | positioned between an imaging means and an eyeball.

  Furthermore, you may make it have an optical fiber arrange | positioned between an imaging means and an eyeball.

  Further, the angle formed by the line of sight of the imaging means incident on the eyeball and the normal of the eyeball at the center of the imaging area may be configured to be within 10 °.

  Furthermore, you may make it have a fixing tool which fixes a tooth | gear and a forehead.

  The eye movement measurement apparatus of the present invention has an advantage that the movement of the eyeball can be accurately measured by imaging the blood vessel pattern of the conjunctiva and / or sclera of the eyeball.

  The best mode for carrying out the present invention will be described below with reference to the drawings. FIG. 1 is a schematic diagram for explaining an eye movement measuring apparatus of the present invention. As shown in FIG. 1, the eye movement measuring device of the present invention mainly includes an imaging device 3 including a camera 1 and a lens 2, an adjustment mechanism 4, an image processing unit 5, a measuring unit 6, and a monitor 7. . Moreover, you may provide the light source 8 which illuminates an eyeball as needed.

  The camera 1 is a camera capable of high-speed photography, and is preferably a digital camera capable of high-speed photography. The lens 2 is a high magnification lens. Then, the imaging device 3 is appropriately set with an imaging area, resolution, shutter speed, frame speed, and the like so as to be able to capture eye movements. Specifically, the camera 1 and the lens so that an imaging area of at least 200 μm to 5000 μm square can be imaged at a resolution of 1 μm to 10 μm at a shutter speed of 0.01 seconds or faster and / or 100 frames / second or more. 2 is selected. More specifically, the camera 1 can use, for example, FASTCAM (registered trademark) manufactured by Photoron Corporation. For example, when a 1 million pixel FASTCAM (registered trademark) capable of imaging at 1000 frames / second is used, if the lens 2 has an optical magnification of 10 times, a resolution of about 2 μm / pixel can be realized. Under these conditions, tremor is not sufficient for precise measurement of fixation microtremors, but sufficient spatial resolution is available for measuring other flicks and drifts. doing.

  The adjustment mechanism 4 can arbitrarily adjust the position of the imaging area of the imaging device by adjusting the position of the imaging area of the imaging device 3. Specifically, any adjustment base having two degrees of freedom in the front, rear, left, and right may be used. Note that the adjusting mechanism is not physical, and may be adjusted by software. That is, a desired frame may be selected from a wide imaging area, and the position of this frame may be adjusted by software. The position of the imaging area is adjusted by the adjustment mechanism 4 so that the sclera surface has the same height as the center of the eyeball, for example. Moreover, in order to adjust more accurately and stop the movement of the head, a fixture for fixing the head of the person to be measured may be used as necessary. This is because, when trying to measure the eye movement more accurately, it is unclear whether the eyeball is rotating or the head is rotating unless the head is fixed. Specific examples of the fixture include a combination of a rod-like member that is bitten with teeth and a plate-like member that presses a forehead portion. By firmly fixing the head with the fixing tool, it is possible to eliminate the rotation of the head and to accurately measure the eye movement.

  Further, the adjustment mechanism can be configured to automatically and freely set the position of the imaging device using an actuator or the like. It is also possible to take an image of an eye angle or the like at the same time and compensate for the movement of the head based on this position.

  The image processing unit 5 is composed of an electronic computer such as a personal computer, and performs various image processing. That is, the image processing unit 5 performs image processing on the image captured by the imaging device 3 so that the conjunctiva of the eyeball or the blood vessel pattern of the sclera can be recognized and tracked. Specifically, the image processing unit 5 first performs noise removal processing as preprocessing on the captured image. In normal high-speed camera shooting, the exposure time is very short, so illumination with a sufficient amount of light is necessary to achieve proper exposure. However, since it is difficult to pick up an image by applying strong light to the eyeball, an image is picked up with a low light quantity, and therefore random noise such as high-sensitivity noise gets on the image. Therefore, in order to remove such noise, noise removal processing, for example, median filter processing is performed. Further, due to the characteristics of the lens 2 or the like, there may be a case where a decrease in peripheral light amount called vignetting or vignetting appears in the captured image. In addition, there may be a deviation in brightness due to irradiation spots of the light source 8 that illuminate the eyeball. Therefore, vignetting correction and irradiation spot correction may be performed as necessary so as to correct such bias. Such correction can be performed by dividing an image obtained by capturing an eyeball by an image obtained by photographing a blank sheet in advance.

  Further, the image processing unit 5 may be configured not to use the image at the moment of blinking if necessary. Specifically, when images that are sequentially picked up are largely different from each other, processing may be performed so as to omit the images between them. Further, if necessary, the process of removing the influence of wrinkles and wrinkles, the influence of shadows, and the like from the image may be performed.

  Next, the moving amount of the eyeball is calculated by the measuring unit 6 with respect to the image to which the predetermined processing is added in the image processing unit 5 in this way. The measuring unit 6 may be composed of an electronic computer such as a personal computer, and may be the same as the electronic computer of the image processing unit. First, the measurement unit 6 sets a reference frame. The reference frame refers to one frame image designated in advance as a base for performing matching with a predetermined pattern in a captured image. In matching, matching is not performed between two consecutive frames, but matching with a preselected reference frame is performed. This is because the amount of movement of the eyeball may be a sub-pixel (1 pixel or less) on the image, and therefore, if the amount of movement is calculated between successive frames, an accumulated error occurs. Accordingly, the reference frame is determined in advance by visual recognition, for example, and is used for matching with each frame to calculate the movement amount.

  As the predetermined pattern, it is possible to use an eyeball conjunctiva and / or a scleral blood vessel pattern. In the conventional eye movement measurement device, it was impossible to image the conjunctiva and / or sclera blood vessel pattern of the eyeball. However, in the eye movement measurement device of the present invention, the conditions under which the eye movement of the eyeball can be imaged are fixed. Therefore, it is possible to image even the blood vessel pattern of the conjunctiva and / or sclera. Therefore, this may be a predetermined pattern for matching.

  Here, matching between a reference frame and an arbitrary frame of interest will be described. The matching method is well known as a method for judging what an observed pattern is by superimposing an ideal pattern and an observed pattern in pattern recognition. In the present invention, a predetermined pattern in the image of the reference frame is matched with the target frame, and the movement amount of the same pattern is calculated in units of pixels. Here, the matching method mainly includes a template matching method and a structure matching method. In the template matching method, the similarity is determined by superimposing the pattern on the frame of interest as it is and comparing each element (each pixel). In the structure matching method, feature points are extracted from patterns of a reference frame and a target frame, and the degree of similarity is determined by comparing the positional relationship between the feature points. In the eye movement measurement apparatus of the present invention, any matching method may be used. However, when it is difficult to extract a clear feature amount with a small outline or the like in a captured image, it is preferable to employ a template matching method. . As a template matching method, a method using a correlation coefficient, an SSDA (Sequential Similarity Detection Algorithm) method, a least square matching method, and the like are known. The eyeball has only approximately parallel / rotational motion, and the SSDA method is the most preferable among them from the results of actual trials.

Is given. That is, the search image is, for example, a frame of interest, and the reference image is a selected partial region in the standard frame. At this time, the search window and the reference frame in the frame of interest
The position of the search window given by the above equation is most similar to the reference image. That is,

  Note that the above-mentioned matching method based on the SSDA method can detect only when the reference image is translated within the frame of interest, and cannot detect when the region within the frame of interest is geometrically deformed. Basically, only two degrees of freedom can be calculated. Although there is no problem with this, if the least square matching method is used instead of the SSDA method, it is possible to calculate the three-degree-of-freedom rotation of the eyeball, and it is possible to deal with geometric deformation.

  At the end of the processing for each frame, the relative rotation angle of the eyeball is calculated using the reference frame and the target frame. The relationship between the rotation angle and the imaging region will be described with reference to FIG. FIG. 2 is a diagram for explaining the relationship between the rotation angle of the eyeball and the imaging region. As a premise for photographing, it is preferable that the imaging device 3 is oriented toward the center of the eyeball. That is, theoretically, it is most preferable that the optical axis (visual axis) of the camera overlaps with the normal line of the center point of the imaging area, and an area that is out of focus will come out as it deviates. Since the depth of field of the high-magnification lens is very shallow, if the line of sight of the camera deviates from the normal of the eyeball at the center of the imaging area, the distance from the eyeball surface to the imaging plane of the camera will be increased. This is because it will be out of focus and will be blurred. Therefore, in order to avoid this, it is preferable that the angle formed by the line of sight of the imaging unit incident on the eyeball and the normal of the eyeball at the center of the imaging area is about 10 ° or less.

Now, in calculating the eyeball rotation angle from the amount of movement between frames, when the frame of interest moves on the image by m pixels, if the relative rotation angle of the eyeball is θ as shown in FIG. θ ′ is expressed by the following equation.
Where r is the radius of the eyeball (assuming the eyeball is a true sphere), λ is the length of the focal plane (focus plane) corresponding to one side of one pixel, l is the apparent distance of movement of the eyeball surface, and l = m × λ. Note that θ ′ is a value obtained by approximating the surface of the eyeball in the captured image as a plane instead of a spherical surface. Such an approximation is possible because the imaging area is small relative to the size of the eyeball.

Here, as the center point in the reference frame, it is necessary to select a point that exists in all other frames. Thereby, θ ′ is suppressed to a predetermined value or less. The error at this time will be specifically described. The length of one side of the square imaging range on the focal plane is 2 s, and the distance from the imaging plane of the imaging apparatus to the focal plane is wd. In FIG. 2, O is the center of the eyeball, and L is the image.
This is the limit point. At this time, focusing on the similarity between ΔLBC and ΔLDE, the following equation can be derived.
Here, measured values of r, s, wd, and λ when using an objective lens having an optical magnification of 5 (r = 11.5 mm, s = 0.98 mm, wd = 64 mm, λ = 3.8 μm / pixel) ) Is substituted into the above equation, the error θ′−θ is as shown in the graph of FIG. The error is 0.000159 radians even at the end of the imaging range where the error occurs most. For example, when the resolution of one side of the image sensor of the camera is 512 pixels, the influence of this error is about 1/3 pixel shift on the image, and can be ignored.

  As described above, it is possible to calculate a relative eyeball rotation angle from the reference frame for each frame, obtain an eyeball rotation angle between successive frames as necessary, and measure a series of eyeball rotation motions. The measured rotational motion is displayed on the monitor 7. FIG. 4 shows an example of the state of the fixation eye movement of the displayed eyeball. In this way, it is possible to trace the trajectory of eye movements with high resolution and accuracy. Note that the monitor 7 is connected to the camera 1 and the image processing unit 5 as necessary, and can be used for visual check of a captured image and an image processed image.

  Here, in the above-described illustrated example, the eyeball that measures the eyeball movement by directing the imaging device directly toward the eyeball to be imaged is shown. However, the present invention is not limited to this, and as described below, imaging is performed. You may comprise so that the position of an apparatus may be installed in arbitrary places and an eye movement may be measured indirectly. In other words, it is possible to arrange the mirror between the imaging device and the eyeball so that the line of sight of the imaging device is refracted by the mirror so that the imaging device is installed at a position that does not block the line of sight of the eyeball, for example. When the imaging device is directly directed to the eyeball, the line of sight of the eyeball may be blocked or the field of view may be narrowed due to the size of the imaging device itself. However, by providing the mirror in between as described above, it is possible to avoid the problem of obstructing the field of view due to the imaging device itself.

  Further, instead of the mirror, for example, an optical fiber may be disposed between the eyeball and the imaging device so that the line of sight of the imaging device is guided from an arbitrary position to the eyeball. When an optical fiber is used, the distance from the imaging device to the eyeball can also be adjusted. In the case of a mirror, the installation position of the imaging device is determined by the position of the eyeball and the focal length of the lens. Therefore, even if a mirror is installed, the total distance from the eyeball to the imaging device is the same as when no mirror is provided. However, in the case of an optical fiber, the total distance can also be set arbitrarily, so that the imaging device can be installed at an arbitrary location.

  In the above description, an example in which one eye movement measurement device is used for one eyeball has been described. However, the present invention is not limited to this, and at least two eye movement measurement devices are used in synchronization. It may be configured to calculate the three-degree-of-freedom rotation position of the eyeball with high accuracy by imaging different areas with respect to the eyeball and measuring the movement of the eyeball. Even with a single eye movement measurement device, it is possible to measure a rotational position with three degrees of freedom, but since the imaging area is very small, for example, the areas on both sides of the eyeball are imaged simultaneously in order to increase the accuracy of the rotation angle. This makes it possible to measure the rotational position of the three degrees of freedom of the eyeball with high accuracy. When a plurality of eye movement measurement devices are used, it is of course possible to use a plurality of imaging devices, or to use a single image processing device, a measurement unit, a monitor, etc. in common.

  Furthermore, you may comprise so that both eyeballs may be measured using at least two eye movement measuring devices. In this case, for example, the measurement unit calculates in advance the rotation angle of both eyeballs when gazing at the target at a known position as a reference angle, and both eyeballs when gazing at the reference angle and the unknown position It is also possible to measure the position of the line of sight of the person being measured from the difference from the rotation angle. In this case as well, a plurality of imaging devices may be used, and the following image processing, measurement unit, monitor, and the like may be configured to use one in common. In the conventional apparatus, the error was about 0.5 °. However, in the case of the apparatus of the present invention, the error can be suppressed to about 0.0002 ° or more, so the line-of-sight position can be very accurately detected. Measurement is possible.

  Further, a camera having a wide-angle lens that can image the entire eyeball may be further provided so that the position of the conjunctiva and / or sclera of the eyeball can be quickly detected. In addition, you may use the imaging device comprised so that a common camera can switch and image by switching a high magnification lens and a wide angle lens. In this case, the image processing unit 5 performs image processing on the wide-angle image first picked up by the wide-angle lens so that the position of the conjunctiva and / or sclera can be searched. The adjustment mechanism 4 is used to manually or automatically adjust the position of the imaging area according to the position of the conjunctiva and / or sclera, and then switch to a high-magnification lens to image the blood vessel pattern of the conjunctiva and / or sclera. To do. When the position is adjusted manually, the image picked up on the monitor 7 is displayed and adjusted by the adjusting mechanism 4 while referring to this image. When the position is automatically adjusted, for example, a feature pattern such as an iris or an eye angle is searched from a wide-angle image, and a high magnification is applied to the position of the conjunctiva and / or sclera determined in advance based on the position. The adjustment mechanism 4 may be automatically adjusted so as to match the line of sight of the lens, or a zoom-in operation may be performed with a zoom lens. If necessary, a mark indicating an imaging area by a high-power lens may be displayed on a wide-angle image on the monitor. The mark may be a frame surrounding the imaging area, or a mark indicating the corner position of a square imaging area.

  Furthermore, the reference frame can be set while continuously capturing images. For example, when the current imaging area exceeds the imaging range of the reference frame due to eye movements, the movement amount of the eyeball set based on the new reference frame is measured from the previously captured image as the reference frame can do. An arbitrary rotation angle of the eyeball can be measured by adding the eyeball rotation angle represented by the old and new reference frame images.

  Further, the adjustment mechanism 4 is used to sequentially move the position of the imaging area of the imaging device so that each part of the conjunctiva and / or sclera of the eyeball can be sequentially imaged, and the image processing unit 5 sequentially captures images. You may comprise so that an image may be joined. This enables imaging of a conjunctival and / or scleral blood vessel pattern in a wider area.

  Note that the measurement unit 6 can perform matching by pattern recognition as described above using sequentially captured images, and can follow the rotation of the eyeball in conjunction with the adjustment mechanism 4. Specifically, first, the feature region of the feature portion is extracted from one of the images picked up by the image processing unit 5, and the same region as the feature portion is searched in the subsequent images picked up sequentially, and the measurement portion At 6, the rotation angle of the eyeball is measured. Then, the position of the imaging area of the imaging device 3 is adjusted by the adjusting mechanism 4 according to the angle. With this configuration, it is possible to measure the eye movement in a wide range following the rotation of the eyeball. Note that, if necessary, the images sequentially captured as described above may be connected.

  Note that the eye movement measurement device of the present invention is not limited to the above-described illustrated examples, and it is needless to say that various modifications can be made without departing from the gist of the present invention.

  For example, in the eye movement measurement apparatus of the present invention, it is possible to measure the conjunctiva and / or scleral blood vessel pattern of the eyeball. Therefore, the conjunctival and / or scleral blood vessel pattern in the past images captured in advance. And the current image can be used for authentication of animals and humans. Since the blood vessel pattern of the conjunctiva and / or sclera is a unique pattern that differs from person to person, it can be used for authentication such as personal authentication. In addition, since the blood flow can also be seen, it is not easy to imitate it using a model or the like in engineering, so it is highly reliable. Furthermore, since capillaries change with age, they can be used as a biometric authentication method that is effective only for a certain period. Furthermore, it is of course possible to combine authentication methods using the fundus, iris, etc., or to combine other authentication methods, such as authentication methods using fingerprints, voiceprints, voices, veins, etc., separately.

FIG. 1 is a schematic diagram for explaining an eye movement measuring apparatus of the present invention. FIG. 2 is a diagram for explaining the relationship between the rotation angle of the eyeball and the imaging region. FIG. 3 is a graph showing the error θ′−θ. FIG. 4 is an example of a state of microscopic eye movements of the displayed eyeball.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Camera 2 Lens 3 Imaging device 4 Adjustment mechanism 5 Image processing part 6 Measuring part 7 Monitor 8 Light source

Claims (13)

An eye movement measuring device for measuring eye movement, the device comprising:
Imaging capable of imaging an imaging area of at least 200 μm to 5000 μm square with a resolution of 1 μm to 10 μm at a shutter speed of 0.01 seconds or faster and / or 100 frames / second or more so as to be able to image fixation eye movements of the eyeball. Means,
Adjusting means for adjusting the position of the imaging area of the imaging means;
Image processing means for image processing an image picked up by the image pickup means so as to be able to recognize and track a blood vessel pattern of the conjunctiva and sclera of the eyeball;
Measuring means for measuring eye movement using an image processed by the image processing means;
Display means for displaying an image captured by the imaging means or an image processed by the image processing means or a measurement result by the measurement means;
An eye movement measuring device comprising:
  2. The eye movement measurement apparatus according to claim 1, wherein the measurement unit extracts a conjunctival and / or scleral blood vessel pattern from the image processed image, and the conjunctival and / or scleral blood vessel pattern. An eye movement measuring device that calculates a rotation angle of an eyeball from a moving position of the eyeball.   3. The eye movement measurement device according to claim 2, wherein at least two eye movement measurement devices are used in synchronization with each other, and images of different regions of one eyeball are imaged to measure the movement of the eyeball. An eye movement measuring device characterized by calculating a rotational position with three degrees of freedom.   4. The eye movement measurement device according to claim 1, further comprising a wide-angle imaging unit capable of imaging the entire eyeball, wherein the image processing unit is an eyeball conjunctiva and / or sclera. The wide-angle image picked up by the wide-angle image pickup means is subjected to image processing so that the position can be searched, and the adjusting means uses the wide-angle image processed by the image processing means to match the position of the conjunctiva and / or sclera. The eye movement measuring device is characterized in that the position of the imaging area is adjusted manually or automatically.   5. The eye movement measurement apparatus according to claim 4, wherein the display means displays mark means indicating an imaging area of the imaging means on a wide angle image picked up by the wide angle imaging means. apparatus.   6. The eye movement measuring apparatus according to claim 1, wherein the adjusting means positions an imaging area of the imaging means so that each part of the conjunctiva and / or sclera of the eyeball can be sequentially imaged. An eye movement measuring device characterized by being sequentially moved, and the image processing means stitches images sequentially picked up.   7. The eye movement measurement device according to claim 1, wherein the image processing means performs feature region extraction of sequentially captured images, searches for the same feature region in the subsequent image, and the same feature region is detected. If not, another new feature region is extracted to search for the same feature region in the subsequent image, and the measuring means measures the rotation of the eyeball based on the searched feature region. apparatus.   The eye movement measuring apparatus according to claim 1, further comprising an authentication unit that compares and authenticates a past image and a current image.   3. The eye movement measurement device according to claim 2, wherein both eyeballs are measured using at least two of the eye movement measurement devices in synchronism with each other, and the measurement means is used for gazing at a target at a known position. An eye movement measuring apparatus that calculates the rotation angle of both eyeballs as a reference angle and measures the position of the line of sight from the difference between the rotation angle of both eyeballs and the reference angle when gazing at an unknown position.   The eye movement measurement apparatus according to claim 1, further comprising a mirror disposed between the imaging unit and the eyeball.   The eye movement measurement apparatus according to claim 1, further comprising an optical fiber disposed between the imaging unit and the eyeball.   12. The eye movement measurement device according to claim 1, wherein an angle formed between a line of sight of the imaging unit incident on the eyeball and a normal of the eyeball at the center point of the imaging area is within 10 °. A characteristic eye movement measurement device.   The eye movement measurement apparatus according to claim 1, further comprising a fixture for fixing a tooth and a forehead.