JP3347514B2 - Eye optical system simulation device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an eye optical system simulation apparatus, and more particularly to an eye optical system simulation apparatus for simulating a retinal image when an optical lens such as a spectacle lens is worn.

[0002]

2. Description of the Related Art Optical lenses such as spectacle lenses, contact lenses, and intraocular lenses are used to maintain normal vision. Many optical lenses having different optical characteristics are sold. When the classification of spectacle lenses is roughly classified by optical specifications, they are classified into a single focus lens having one focus in one lens and a multifocal lens having a plurality of focuses in one lens. Further, the single focus lens is divided into a spherical lens and an aspheric lens. The design of the aspherical lens varies from manufacturer to manufacturer. Similarly, multifocal lenses are also classified into many types.
For example, there are a bifocal lens, a trifocal lens, and a progressive multifocal lens, and these lenses are further subdivided.

When selecting an optical lens, a lens suitable for a wearer is selected from lenses having various optical specifications. As a judgment material in the selection, a clerk makes a selection by preparing a plurality of types of lenses having a lens power suitable for the wearer and actually wearing the lens, or a clerk of an eyeglass store listening to the request of the wearer. There was a way.

[0004] However, it is actually difficult to own a plurality of lenses having different powers suitable for the wearer according to optical specifications in a spectacle store because of the large number of types. On the other hand, the method in which the clerk asks the wearer for his / her request and makes a selection requires skill of the clerk. Further, it is difficult for the clerk to always make an accurate judgment because the clerk cannot know what the wearer actually looks like.

In order to solve such a problem, there is an eye optical system simulation apparatus capable of simulating a retinal image when an optical lens is worn. In the eye optical system simulation apparatus, first, a parallel light beam from a light source screen is traced in an optical system such as an optical lens and a cornea to obtain a PSF (Point Spread Function). P
The SF is a function representing how light emitted from one point on the object is distributed on the image plane. Retinal image data is calculated from the PSF and the image data. By displaying the retinal image data corresponding to the image data thus obtained on the screen of the display device, it is possible to objectively determine how the image is viewed. As such an example, the present applicant has filed Japanese Patent Application No. 7-26936.

[0006]

However, when actually seeing an object, despite the fact that the brain recognizes the object by fusing the image projected on the retina of each of the left and right eyes, In a conventional eye optical system simulation apparatus, a simulation is performed without considering the difference in the appearance of an image between both eyes. Therefore, even if you simulate the eye optical system for each of the left and right eyes and select the optimal optical lens, it is not certain whether the lens is really optimal in terms of legibility when actually wearing glasses etc. Absent. This is because if the size and shape of the images reflected on the left and right retinas are large, the brain will hinder the fusion. For example, it is known that it is difficult to fuse the left and right images when the sizes of the images shown on the left and right retinas are different, particularly when the sizes in the height direction are different.

Normally, the right eye and the left eye of a person have different visual acuity. Therefore, the images projected on the left and right retinas are not exactly the same, regardless of whether or not the vision is corrected with glasses or the like. If such a shift in the image is very small, there is no problem when the brain is fused. However, for a person who has myopia with only one eye, if the vision is corrected for only one eye, the deviation between the left and right images may increase.

Further, when one of the eyes suffers from cataract and uses an intraocular lens, the displacement between the left and right images tends to increase, and if the intraocular lens is inserted, it cannot be easily replaced. Therefore, it is necessary to confirm the difference in the appearance of the image between the two eyes before performing the operation of inserting the intraocular lens.

SUMMARY OF THE INVENTION The present invention has been made in view of such a point, and an object of the present invention is to provide an eye optical system simulation apparatus capable of easily confirming a difference in the appearance of an image between both eyes. .

[0010]

According to the present invention, there is provided an ophthalmic optical system simulation apparatus for simulating a retinal image when an optical lens is worn, comprising: a light source screen placed at a predetermined position; A PSF (Point Spread FPS) in each of the left and right eye optical systems based on the optical lens provided in one or both of the left and right eye optical systems and optical system data on the left and right human eyes.
unction) and the left and right persons
Of the optical system data on the eye, the axial length of the eye or the convexity of the cornea
Determining means for determining the radius of curvature of the surface according to the eyesight of the wearer
And a retinal image calculating means for calculating a retinal image in each of the left and right eye optical systems based on the image data placed at a predetermined position and the PSF. Provided.

[0011]

The PSF calculating means is configured to determine the right and left eye light based on the light source screen placed at a predetermined position, the optical lens provided on one or both of the left and right eye optical systems, and the optical system data on the left and right human eyes. PSF (Poin
t Spread Function). Left and right eyes
The data is, for example, using a model of glustrand,
The radius of curvature of the convex surface of the long or cornea depends on the eyesight of the wearer
The retinal image calculation means determines the retinal image in each of the left and right eye optical systems based on the image data and the PSF placed at a predetermined position.

Thus, it is possible to perform a simulation of a retinal image in which the difference in the appearance of the image between the two eyes can be easily confirmed.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram illustrating the principle of the eye optical system simulation apparatus according to the present invention. The optical system data 4 includes a light source screen on which an image to be simulated is displayed, and data on left and right human eyes such as an optical lens, cornea, pupil, crystalline lens, and retina. The light source screen is set at an arbitrary position. The optical system data on the optical lens is obtained from the design value of the lens. The data relating to the left and right human eyes is basically obtained using a model of glustrand, and the value of the axial length or the radius of curvature of the convex surface of the cornea is determined according to the eyesight of the wearer. In addition, measurable data can be measured directly from the wearer.

The optical system data 4 is the optical system data 4 of the right eye.
a and the left eye optical system data 4b. The right-eye optical system data 4a and the left-eye optical system data 4b are optical system data in a state where the same light source screen is viewed. In other words, the rotation angle of the human eye is set so that the viewpoints of the left and right eyes are on the same light source screen, taking into account the convergence perspective of both eyes. Thereby, the optical system data 4a of the right eye and the optical system data 4b of the left eye are specified.

The PSF (Point Spread Functio) corresponds to the optical system data 4a of the right eye and the optical system data 4b of the left eye.
n) Operation means 5 and 6 are provided. The PSF calculation means 5 and 6 determine the respective PSFs 7 and 8 based on the optical system data 4a for the right eye and the optical system data 4b for the left eye. PS
F7 and F8 are functions representing how light emitted from a certain point is distributed on the image plane. The retinal image calculation means 2 and 3
The image data 1 set as the target is converted into the respective PSFs.
Convolution integration is performed by 7 and 8 to generate right eye retinal image data 9 and left eye retinal image data 10. The images of the retinal image data 9 and 10 are blurred with respect to the target.

The display control means 11 controls the retinal image data 9, 1
0 is displayed on the display screen of the display device 12. Display device 1
2 displays, for example, side by side in one screen so that the retinal image 12a of the right eye and the retinal image 12b of the left eye can be easily compared. By comparing the size, the degree of blur, or the degree of distortion of the displayed left and right retinal images, it is possible to objectively determine the difference between the images shown on the left and right retinas. Therefore, it is easy to select a lens having a small error between the left and right retinal images, and it is possible to prevent the occurrence of a fusion failure due to an erroneous selection of the optical lens.

Next, an example of a simulation assuming that eyeglasses are worn will be described in detail. FIG. 2 is a diagram showing an eye optical system of both eyes. This shows a state in which the optical system of the wearer whose eyesight has been corrected by eyeglasses is viewed from above. The right eye 23 and the left eye 24 are separated by an interpupillary distance “D”.
Just away. As the interpupillary distance, an actual value of the wearer is measured, or an average value according to the age and gender of the wearer is used. Both eyes face the light source screen 20 via spectacle lenses 21 and 22 corresponding to their respective eyesights. The light source screen 20 is separated from the straight line connecting the eyes by a distance “L”.

[0018] Here, the center of rotation O _R of both eyes, a straight line passing through the center point of the O _L and the spectacle lens 21, defined as the reference axis 27, 28 in the respective optical systems, the center of the cornea of the human eye a straight line connecting the center of rotation O _R, and O _L, the reference axis 27,
28 are defined as rotation angles θ _R and θ _L. Then, the rotation angles θ of both eyes for directly facing the light source screen 20
_R and θ _L can be obtained from the interpupillary distance “D” and the distance “L” to the light source screen. In addition, the light 25 and 26 incident on both eyes from the light source screen 20 are the spectacle lenses 21 and
As it passes through the interior 22, the direction changes. Therefore, the angles formed by the light beams 25 and 26 and the reference axes 27 and 28 are slightly different from the rotation angles θ _R and θ _L.

The optical system data for the right eye and the optical system data for the left eye are set based on the optical system under such conditions. In addition to the distance between the pupils, the angle of rotation, and the distance to the light source screen, the refractive index of the spectacle lens and the radius of curvature of the convex and concave surfaces are set based on the design values of the lens. Among the data related to the human eye, the refractive index and the radius of curvature in the cornea and the like use values of a model of a glustrand, and the axial length is set according to the visual acuity of the human eye to be simulated.

The PSF calculation means calculates the PSF of each of the eyes based on the optical system data of the right and left eyes. PS
F is a function representing how light emitted from one point on a certain object is distributed on the image plane. The PSF is obtained by tracing n rays equally distributed in each direction from one point on the object plane toward the image plane, and obtaining the density of rays intersecting the image plane. In general, it is determined from the imaging theory of geometrical optics. However, in an optical system having a small aberration and an optical system including a diffractive element, an imaging theory based on wave optics may need to be applied. Determined by integration.

The retinal image calculation means performs convolution integration of the monochromatic image data and the PSF, which correspond to each other,
Retina image data of the right eye and the left eye is obtained. The light intensity distribution of the ideal image on the image plane is represented by f (y, z) and P at the point (y, z).
Assuming that SF is p (x, y, u, v), the light intensity at the point (y, z) on the retina can be expressed by the following equation.

[0022]

(Equation 1)

Here, p (u, v, uy, uz) is the value of the PSF at a point (uy, vz) apart from each point (u, v). A is the spreading radius of the PSF. By calculating the light intensity at all points on the retina using this formula, the left and right image data are obtained.

The retinal image data obtained in this way is
The display control means causes the display device to display. This allows
The images projected on the retinas of both eyes can be simulated on the screen of the display device, and the difference between the respective retinal images can be confirmed.

The following is an example of a retinal image generated by simulation when the Landolt's eye ring is used as image data. FIG. 3 shows a Landolt visual ring used as an image. Each of the Landolt optics 40 has a visual acuity of.
41 for 2; 42 for sight 0.3; 4 for sight 0.4
3, 44 for 0.5, 45 for 0.6, 0.7 for vision
46 for sight, 47 for sight 0.8, 48 for sight 0.9,
It consists of 49 for vision 1.0. This Landolt eye ring 40
The total size is 250 × 250 pixels, and the pixel interval is 0.001 mm. The Landolt visual ring 40 is written in black on a white background.

The Landolt's eye ring 40 is simulated by the optical systems of the right eye and the left eye.
The retinal images generated as a result are displayed side by side on the screen of the display device.

FIG. 4 is a diagram showing left and right retinal images obtained from image data of Landolt's visual annulus. The right half of the display screen 50 is a retinal image 50a of the right eye, and the left half is a retinal image 50b of the left eye.

[0028] 51a-59a in the retinal image 50a of the right eye
Are images corresponding to the Landolt visual rings 41 to 49 in FIG. Note that the retinal image is actually a so-called blurred image with continuous shading, but this is shown by contour lines in FIG. In other words, the density becomes deeper toward the center of each retinal image and becomes thinner toward the outside.

51b to 59b in the retinal image 50b of the left eye
Are images corresponding to the Landolt visual rings 41 to 49 in FIG. In this example, the degree of blur of the retinal image of the left eye is smaller than that of the right eye. As described above, when the left and right retinal images are not the same, by changing the data of the spectacle lens of one of the optical systems, a spectacle lens that minimizes the shift of the retinal image is selected. This makes it possible to select a lens that is balanced with respect to the correction of the visual acuity of both eyes and the ease of fusion of the retinal images of both eyes.

In FIG. 4, the left and right retinal images are displayed side by side, but two retinal images can be superimposed and displayed on the screen. By superimposing the two retinal images, it is possible to compare subtle shifts of the retinal images, and it is possible to more strictly select a lens having a small shift between the left and right retinal images.

In addition to superimposing the retinal images, the left and right retinal images may be moved to arbitrary positions on the screen. By freely moving the positions of the left and right retinal images, the comparison of the retinal images can be further facilitated. For example, in FIG. 4, when comparing the vertical size difference between the left and right retinal images, the retinal image 50a of the right eye is moved, and the upper end of the Landolt's sight ring 51a is moved.
b. Thus, Landolt's eye ring 5
It is possible to easily discriminate a vertical size difference between the 1a and the Landolt visual ring 51b.

Further, such a simulation result can be used to understand the fusion processing performed by the human brain. For example, the subject wears spectacles in which the difference between the left and right retinal images is large, and determines the visibility of the object. This is done with various lens combinations.
From this result, it is possible to analyze what kind of shift occurs between the left and right retinal images and the fusion fault occurs.

Next, hardware for performing the above-described simulation will be briefly described. FIG. 5 is a block diagram of the hardware of the workstation for performing the above simulation.

As shown in the figure, the workstation is:
A processor 61, a graphic control circuit 64, a display device 65, a mouse 66, a keyboard 67, a hard disk device (HDD) 68, a floppy disk device (FD)
D) 69, a printer 70, and a magnetic tape device 71. These elements are connected by a bus 72.

The processor 61 controls the whole workstation. The read-only memory 62 stores a program required at the time of startup. The main memory 63 stores a simulation program and the like for performing a simulation.

The graphic control circuit 64 includes a video memory and converts the obtained retinal image data into a display signal.
It is displayed on the display device 65. The mouse 66 is a pointing device for controlling the mouse on the display device and selecting various icons and menus.

The hard disk drive 68 stores a system program and a simulation program, and is loaded into the main memory 63 after the power is turned on. In addition, simulation data and the like are temporarily stored.

The floppy disk device 69 inputs necessary data such as original image data from the floppy 69a, and saves the data to the floppy 69a as necessary. The printer 70 is used to print out PSF, retinal image data, and the like.

The magnetic tape device 71 is used for saving simulation data to a magnetic tape as required. Note that a high-performance personal computer or a general-purpose computer other than the workstation may be used.

In the above example, the optical system is configured with the optical lens to be worn as a spectacle lens. However, if the optical system is configured with a contact lens or an intraocular lens as an optical lens and a simulation image is obtained, It is also useful for selecting a contact lens or an intraocular lens.

[0041]

As described above, according to the present invention, based on the optical system data of each of the left and right eyes, a retinal image when an object is viewed with each eye is simulated. It is easy to confirm the difference between the two, and it is possible to select a lens in consideration of the ease of fusion of the retinal images of both eyes. In particular, optical system data
The inner axial length of the data or the radius of curvature of the convex surface of the cornea
According to the eyesight of the wearer
Simulation can be appropriately performed.

[Brief description of the drawings]

FIG. 1 is a principle diagram of an eye optical system simulation apparatus according to the present invention.

FIG. 2 is a diagram illustrating an eye optical system of both eyes.

FIG. 3 is a diagram showing a Landolt visual ring used as an image.

FIG. 4 is a diagram showing left and right retinal images obtained from Landolt's visual ring image data.

FIG. 5 is a hardware block diagram of a workstation for performing a simulation according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Image data 2, 3 Retinal image calculation means 4 Optical system data 4a Right eye optical system data 4b Left eye optical system data 5, 6 PSF calculation means 7, 8 PSF 9 Right eye retinal image data 10 Left eye retinal image data 11 display control means 12 display device 12a right eye retinal image 12b left eye retinal image

Continuation of the front page (56) References JP-A-6-201990 (JP, A) JP-A-61-1740 (JP, A) JP-A-3-121412 (JP, A) JP-A-2-305544 (JP) JP-A-5-154109 (JP, A) JP-A-2-198547 (JP, A) JP-A-7-100107 (JP, A) JP-A-61-85917 (JP, A) 6-215084 (JP, A) JP-A-4-50813 (JP, A) JP-A-1-40926 (JP, A) JP-A-4-327831 (JP, A) Kehua, Takaya Nezu, Akira Shimojo, Norio Hirayama, Goro Ikeda, Kazuhiko Onuma, Simulation of Image of Eye Optical System, Science of Vision, Japanese Society of Ophthalmology, August 25, 1984, Vol. 15, No. 3, p. 171-176 Rafael Navarro, Manuel Ferro, Pblo Artal, Israel Miranda, Modulation trans functions of the evolved with the use of ICT. 32, No. 31, p. 6359-6367 Shunichi Kaneko, Rinko Oya, Yogo Honda, Modeling of Blur Characteristics in Vision and Binocular Stereoscopic Display Using It, Proceedings of the 40th National Convention of IPSJ (p. I), p. 109-110 Pavlo Artal, Javier Santamaria, Julian Bescos, Optical-digital procedure for the reti- nal ima- ges of a point of interest, GOT RICE, GOT RICE, G.I. 28 No. 6, p. 687-690 (58) Fields surveyed (Int. Cl. ⁷ , DB name) A61B 3/00-3/16 JICST file (JOIS)

Claims (5)

(57) [Claims] 1. An ophthalmic optical system simulation apparatus for simulating a retinal image when an optical lens is worn, wherein a light source screen placed at a predetermined position and one or both of the left and right ocular optical systems are provided. A point spread function (PSF) in each of the left and right eye optical systems based on the optical lens and optical system data on the left and right human eyes.
), And the optical axis data of the left and right human eyes,
The radius of curvature of the convex surface of the cornea is determined according to the eyesight of the wearer
And a retinal image calculating means for calculating a retinal image in each of the left and right eye optical systems based on the image data placed at a predetermined position and the PSF. Simulation device. 2. The ophthalmic optical system simulation according to claim 1, wherein the optical system data is data in a state where the left and right human eyes are rotated so that a viewpoint is determined on the light source screen. apparatus. 3. The eye optical system simulation apparatus according to claim 1, further comprising display control means for displaying the retinal image on a display device. 4. The apparatus according to claim 3, wherein the display control means displays the retinal images of the left and right eye optical systems in the same screen. 5. The display control means according to claim 1, wherein said retinal image in each of said left and right eye optical systems is displayed on the same screen, and said retinal image can be moved to an arbitrary position on the screen. 4. The eye optical system simulation apparatus according to 3.