JP2016073361A - Ophthalmologic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ophthalmologic apparatus capable of uniformizing a contribution ratio of an error influencing calculation of wavefront aberration for each point image.SOLUTION: An ophthalmologic apparatus 1010 includes: a fundus illumination optical system 1020 for illuminating a fundus oculi Ef of a subject's eye E; and a wavefront measurement optical system 1030 including a Hartmann plate 1032 that have a plurality of lens arrays for splitting reflection illumination light reflected from the fundus oculi Ef, into a plurality of light fluxes, and a light reception part 1033 that receives the split light fluxes split by the Hartmann plate 1032. The ophthalmologic apparatus extracts a plurality of lens arrays that are located at positions suited for an arithmetic expression for calculating a measurement value, out of the plurality of lens arrays of the Hartmann plate 1032; calculate the wavefront aberration from point images of the light reception part 1033 corresponding to the extracted multiple lens arrays; and measures optical characteristics of the subject's eye E on the basis of the wavefront aberration.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an ophthalmologic apparatus including a Hartmann plate on which a plurality of lens arrays are formed.

  2. Description of the Related Art Conventionally, an ophthalmologic apparatus that measures the refractive power of an eye to be examined using a Hartmann plate is known (see Patent Document 1).

  Such an ophthalmologic apparatus includes an illumination optical system that illuminates the fundus of a subject's eye, a Hartmann plate that divides the reflected illumination light reflected from the fundus into a plurality of light beams, and a light receiving unit that receives the divided light beams divided by the Hartman plate And measuring the refractive power of the eye to be examined based on the positions of a plurality of point images formed on the light receiving unit.

  A plurality of lens arrays arranged in a grid pattern are formed on the Hartmann plate, and a grid-shaped point image is formed on the light receiving portion. The position of the grid-shaped point image and the reference position of each point image are shifted. The refractive power of the eye to be examined is measured based on the amount.

JP 2014-30573 A

  In such an ophthalmologic apparatus, for example, the center on the pupil of the light receiving unit is set as the center position (origin), and the position of the point image is obtained based on the distance and angle from the center position.

  Here, let us consider a case where there is a random error (measurement error or manufacturing error) at the position of each point image. The magnitude of the error Δw is the same for each point image, and if the distance from the center position to each point image is ρ, the contribution ratio of the error given to the measurement value is Δw / ρ, and the farther from the center position, the greater the error Δw. The contribution rate of the error becomes small.

  Since a plurality of lens arrays are formed in a lattice shape on the Hartmann plate, as shown in FIG. 16, a point image is formed in a lattice shape on the light receiving surface of the light receiving element S1.

  When the wavefront aberration is obtained based on a point image within the range of φ3 (diameter 3 mm), for example, with the origin O of the light receiving surface as the center, the point image on the outermost peripheral side within this range is, for example, a square frame W1. In the case of the upper point images P1 to P16, assuming that the distance from the origin O of the light receiving element S1 to the point images P1 to P16 is ρ1 to ρ16, ρ1 = ρ5 = ρ9 = ρ13, ρ2 = ρ4 = ρ6 = ρ8 = ρ10 = ρ12 = ρ14 = ρ16, ρ3 = ρ7 = ρ11 = ρ15, and there are three different distances ρ1 <ρ2 <ρ3.

  Here, point images P1, P2, and P3 at distances ρ1, ρ2, and ρ3 are considered. Assuming that the error Δw is included in each point image P1 to P3, the error contribution ratio of each point image P1 to P3 is Δw / ρ1> Δw / ρ2> Δw / ρ3.

  That is, when calculating the wavefront aberration at the positions of the point images P1 to P3, even if the error amounts of the point images P1 to P3 are the same, the contribution ratio of the error to the calculation of the wavefront aberration is the point images P1 to P3. There is a problem in that it becomes impossible to obtain accurate optical characteristics of the eye to be examined.

  An object of the present invention is to provide an ophthalmologic apparatus capable of obtaining accurate optical characteristics of an eye to be examined.

The invention according to claim 1 is divided by the Hartmann plate having an illumination optical system for illuminating the fundus of the eye to be examined, a plurality of lens arrays for dividing the reflected illumination light reflected from the fundus into a plurality of light beams, and the Hartmann plate. An ophthalmologic apparatus comprising a wavefront measuring system having a light receiving unit for receiving the divided luminous flux,
Select a plurality of lens arrays at a position suitable for an arithmetic expression for obtaining a measurement value from a plurality of lens arrays of the Hartmann plate,
A wavefront aberration is obtained from a point image of the light receiving unit corresponding to the selected plurality of lens arrays, and optical characteristics of the eye to be examined are measured based on the wavefront aberration.

  According to the present invention, accurate optical characteristics of the eye to be examined can be obtained.

It is a block diagram which shows the structure of the ophthalmologic apparatus which concerns on this invention. It is explanatory drawing which showed the lens array formed in the Hartmann board shown in FIG. It is explanatory drawing which showed the point image on the light-receiving part formed with the lens array shown in FIG. It is explanatory drawing which showed arrangement | positioning of the point image of 2nd Example. It is explanatory drawing which showed arrangement | positioning of the lens array of 2nd Example. It is a graph which shows the degree of contribution of the random error with respect to an angle. It is explanatory drawing which showed arrangement | positioning of the point image of 3rd Example. It is explanatory drawing which showed arrangement | positioning of the lens array of 3rd Example. It is the optical arrangement | positioning figure which showed arrangement | positioning of the optical system of the ophthalmologic apparatus of 4th Example. It is the block diagram which showed the structure of the control system of the ophthalmologic apparatus shown in FIG. It is explanatory drawing which shows typically the placido ring pattern seen by the front from the to-be-tested eye side. It is explanatory drawing which showed the placido ring pattern image imaged on the area sensor (its light-receiving surface). It is explanatory drawing similar to FIG. 4 for demonstrating the state from which Z alignment shifted | deviated. It is explanatory drawing which showed typically the illumination light and reflected light of a fundus. It is the flowchart which showed a part of processing operation of the control calculating part. It is explanatory drawing of the monitor screen which displayed the wavefront aberration of the eye to be examined, the simulated Landolt ring, etc. It is explanatory drawing of the monitor screen which displayed the wavefront aberration etc. of the cornea. It is explanatory drawing which showed arrangement | positioning of the conventional point image.

  Hereinafter, an embodiment which is an embodiment of an ophthalmic apparatus according to the present invention will be described with reference to the drawings.

[First embodiment]
FIG. 1 shows the configuration of an ophthalmic apparatus 1010. The ophthalmologic apparatus 1010 includes a fundus illumination optical system (illumination optical system) 1020 that illuminates the fundus oculi Ef of the eye E, and a wavefront measurement optical system (wavefront measurement system) that receives reflected illumination light from the fundus oculi Ef and measures wavefront aberration. ) 1030, an anterior ocular segment illumination optical system 1040 for illuminating the anterior segment Ea of the eye E to be examined, and an observation optical system 1050 for observing the anterior segment Ea.
[Fundamental illumination optical system]
The fundus illumination optical system 1020 includes an illumination light source 1021 that emits infrared laser light having a wavelength of 830 nm, a condensing lens 1022 that collects illumination light emitted from the illumination light source 1021, a polarization beam splitter 1023, an optical aperture 1024, a relay lens 1025, a dichroic mirror 1026, an objective lens 1027, and a dichroic mirror 1028 that reflects infrared light and transmits visible light.

  The dichroic mirror 1026 is set to reflect infrared light with a wavelength of 830 nm and transmit infrared light with a wavelength of 940 nm.

  The dichroic mirror 1028 is set to transmit visible light having a wavelength shorter than about 800 nm and transmit infrared light having a wavelength longer than 800 nm.

  The fundus illumination optical system 1020 adjusts the beam waist position to the image plane position (0.0D) by bringing the position of the illumination light source 1021 to −3D to −13D. In addition, the position of the optical aperture 1024 is set so that the exit pupil position is 200 mm to 300 mm far from the image plane position (behind the fundus).

Further, the illumination light source 1021 is positioned between −3D to −13D, the illumination light source 1021 is arranged so that the fundus oculi Ef position of the eye E to be examined is substantially conjugate with the illumination light source 1021, and the exit pupil position is set to the image plane. Since it is arranged far from the position, the working distance, which is the distance from the apparatus main body to the eye E, can be made variable.
[Wavefront measurement optical system]
The wavefront measuring optical system 1030 includes a dichroic mirror 1028 that receives reflected illumination light from the fundus oculi Ef, an objective lens 1027, a dichroic mirror 1026, a relay lens 1025, an optical aperture 1024, a polarization beam splitter 1023, and a relay lens. 1031, a Hartmann plate 1032, and a light receiving unit 1033 including a CMOS image sensor. The wavefront measuring optical system 1030 shares an optical member in the optical path from the polarizing beam splitter 1023 of the fundus illumination optical system 1020 to the dichroic mirror 1028.

  The Hartmann plate 1032 divides the reflected illumination light from the fundus oculi Ef into a plurality of light fluxes, is in a conjugate relationship with the pupil of the eye E, and is arranged on a plurality of concentric circles as shown in FIG. And a plurality of lens arrays 1032A to 1032E.

  The light receiving unit 1033 is configured to receive the divided light flux divided into a plurality of parts by the Hartmann plate 1032.

Since the Hartmann plate 1032 is in a conjugate position with the pupil of the eye E, the wavefront information of the reflected light beam from the eye E can be optically detected based on the light reception signal of the light receiving unit 1033. The wavefront information includes information related to the refractive characteristics of the eye.
[Anterior illumination optical system]
The anterior segment illumination optical system 1040 includes a light source 1041 formed of a diode that emits infrared light, and a dichroic mirror 1028.
[Observation optics]
The observation optical system 1050 includes a dichroic mirror 1028 that reflects the reflected light from the anterior segment Ea, an objective lens 1027, a dichroic mirror 1026, an imaging lens 1051, and a light receiving unit 1052 including a CCD. .
[Other configurations]
The ophthalmologic apparatus 1010 includes a dichroic mirror rotation control / detection unit 1060 that controls / detects rotation of the dichroic mirror 1028, an inclination angle detection unit 1061, a calculation control unit 1070, and a display unit 1071.

  The dichroic mirror 1028 has a structure that can swing left and right around the direction toward the eye E. This structure is the same as that described in Japanese Patent Application Laid-Open No. 2014-30573, and the description thereof is omitted. Similarly, the operations of the dichroic mirror rotation control / detection unit 1060 and the tilt angle detection unit 1061 are the same as those described in the above-mentioned publication, and thus the description thereof is omitted.

  The arithmetic control unit 1070 obtains a wavefront aberration, a refractive power (optical characteristic), an astigmatic axis (optical characteristic), and the like from the wavefront aberration based on the light reception signal of the light receiving unit 1033.

The display unit 1071 displays the refractive power obtained by the calculation control unit 1070 and the anterior eye image captured by the light receiving unit 1052.
[Operation]
Next, the operation of the ophthalmologic apparatus 1010 configured as described above will be described.

  When infrared light is emitted from the light source 1041 of the anterior ocular segment illumination optical system 1040, the infrared light is reflected by the dichroic mirror 1028 to illuminate the anterior segment Ea of the eye E to be examined. The reflected illumination light reflected by the anterior eye portion Ea is reflected by the dichroic mirror 1028, reaches the dichroic mirror 1026 through the objective lens 1027, passes through the dichroic mirror 1026, reaches the imaging lens 1051, and this imaging lens. An anterior ocular segment image is formed on the light receiving unit 1052 by 1051, and this anterior ocular segment image is displayed on the display unit 1071.

  When infrared laser light having a wavelength of 830 nm is emitted from the illumination light source 1021 of the fundus illumination optical system 1020, the laser light is collected by the condenser lens 1022 and is polarized beam splitter 1023, the optical aperture 1024, and the relay lens 1025. , Then reaches the dichroic mirror 1026, is reflected here and reaches the dichroic mirror 1028 via the objective lens 1027, and is reflected here to illuminate the fundus oculi Ef of the eye E to be examined.

  The fundus reflection illumination light reflected by the fundus oculi Ef is reflected by the dichroic mirror 1028, reaches the dichroic mirror 1026 via the objective lens 1027, is reflected here, and enters the polarization beam splitter 1023 via the relay lens 1025. The fundus reflection illumination light incident on the polarization beam splitter 1023 is reflected here and received by the light receiving unit 1033 via the relay lens 1031 and the Hartmann plate 1032.

  Since the Hartmann plate 1032 is formed with a plurality of lens arrays 1032A to 1032E as shown in FIG. 2, dots are formed on the light receiving portion 1033 along a plurality of circumferences as shown in FIG. Images QA to QE are formed.

  The arithmetic control unit 1070 obtains the center of gravity of each point image QA to QE as the position of each point image based on the light reception signal of the light receiving unit 1033, and further from the reference position (not shown) of each point image QA to QE. A deviation amount of each of the point images QA to QE is obtained, a wavefront aberration is calculated from the Zernike polynomial based on the deviation amount, and a refractive power of the eye E is calculated (measured) based on the wavefront aberration. This refractive power and the like are displayed on the display unit 1071.

The wavefront aberration can be expressed by a Zernike polynomial, for example, which is an orthogonal function as shown in the following equation.

R _n ^m (ρ) in equation (1) is a Zernike polynomial.

This Zernike polynomial can be expressed by equation (2).

The coefficients up to the third order of the Zernike polynomial are shown below.
(coefficient)

  Of these coefficients, equations (3) and (5) indicate the astigmatic axis, and equation (4) indicates the refractive power.

  By the way, when the amount of deviation from each reference coordinate (not shown) of each point of the point image by the Hartmann plate 1032 is known, the inclination of the wave front at the coordinates (x, y or rθ) of each point is known. Since the coordinates of each point are conjugate with the pupil, that is, when the amount of deviation is known, the inclination of the wavefront at the coordinates on the pupil corresponding to the coordinates of the point image by the Hartmann plate 1032 is known.

  In this embodiment, the wavefront is expressed by a Zernike polynomial that is an orthogonal function, and the refractive power is obtained.

  As described above, since it is the slope of the wavefront that can be seen from the point image of the Hartmann plate 1032, the least square approximation is performed using the derivative of the Zernike polynomial (fitting function) and the slope (data point) at the coordinates of each point image, Thus, wavefront aberration is obtained, and refractive power and the like are calculated from the wavefront aberration.

For simplicity, consider the case of fitting with only Z ₂ ⁰ , which is a second-order term of the Zernike polynomial, that is, a term related to refractive power.

Z ₂ ⁰ = C ₂ ⁰ (2r ² -1) (6)
Here, C is the Zernike coefficient, and r is the distance from the image center (or pupil center) to each point image. When this equation (6) is differentiated, the following equation (7) is obtained.

(∂Z / ∂r) = C · 4r = Z ′ (7)
The formula for finding the least squares fitting is
It is expressed. The least square fitting is obtained by obtaining C that minimizes G in the equation (8).

Here, assuming that there is a random error when detecting each point image, Z ′ (r _N ) in the equation (8) is shifted. That is, Z ′ (r _N ) → Z ′ (r _N ) + ΔZ ′.

However, r _N is the distance between the reference coordinates and the image center of each point image obtained in advance (pupil center), [Delta] Z 'is a random error.

When the equation (8) is differentiated, the following equation (9) is obtained.

  Solving this equation (9) will find the least square fitting.

Assuming that Z ′ (r) has a random error, the Zernike coefficient C is calculated from a certain point of data. From (Z ′ (r ₁ ) + ΔZ′−4Cr ₁ ) × (−4r ₁ ) = 0, The Zernike coefficient C is expressed by the following equation (10).

ΔZ ′ / 4r _{1 in the} equation (10) indicates that the contribution to the Zernike coefficient C (contribution when obtaining the Zernike coefficient) is small at a position where r is large even if the random error has the same magnitude. . If r is the same, it indicates that the contribution to the Zernike coefficient C is the same.

  That is, as shown in FIG. 2, when the lens arrays 1032A to 1032E are arranged on the circumference, the contribution of the random error to the Zernike coefficient C is the same in the lens arrays 1032A to 1032E on the same circumference. That is, the contribution ratio of the error to the calculation of the wavefront aberration is the same on the same circumference, so that an accurate wavefront aberration can be obtained, and the refractive power and the like can be accurately calculated from the wavefront aberration.

  Accordingly, it is possible to accurately obtain the refractive power for each different circumference, the total refractive power, and the like. Then, the measurement results such as the calculated refractive power and the total refractive power for each circumference and the calculated wavefront aberration are displayed on the display unit 1071 and provided to the subject.

In this embodiment, the refractive power and the like are obtained from the wavefront aberration, but the center positions (center of gravity positions) of the plurality of point images QA to QE shown in FIG. 3 are connected in the circumferential direction so as to surround the center position of the pupil image. The refractive power of the eye E may be obtained from the shape of the formed line.
[Second Embodiment]
(10) contribute to give the coefficients of the random error Zernike polynomials for each point image from the equation becomes relatively ΔZ '/ 4r _N.

As shown in FIG. 4, from the pupil center (image center) O and on the circumference of radius r = r _i, the point image Qi lens array and on the circumference of radius r _j, and there is Qj, r = r sum of the contributions of the point image Qi on _i gives, when the number of point image and the N _i pieces,
N _i × (ΔZ / 4r _i ) (11)
Similarly, the sum of contributions given by the point image Qj on the circumference of the radius r _j is N _{j when} the number of point images Qj is N _j .
N _j × (ΔZ / 4r _j ) (12)
It becomes. If r _j > ri, the number of N _j must be increased in order for the expressions (11) and (12) to contribute equally to the determination of the Zernike coefficients for each circumference. That _is, the _{N j = N i × r j} / r i.

That is, as shown in FIG. 4, if the number _{N i = 8, r j =} 2 × r i of the point image _Qi, the N j = 16.

As described above, if the point images Qi and Qj are arranged as shown in FIG. 4, that is, if the number and arrangement of the lens arrays Qic and Qjd are set as shown in FIG. The contribution ratio of the error is the same on the circumferences of the different radii r _i and r _j , and a more accurate wavefront aberration can be obtained, so that the refractive power and the like can be measured more accurately.

Since ΔZ ′ is a random error that can be positive or negative, it is canceled when the number of point images becomes infinite. However, the number of lens arrays and the brightness of one point image are a trade-off, so the number can be increased without limit. Is impossible.
[Third embodiment]
Next, consider the case of fitting to the following term (secondary term) including more complicated φ.

Z ₂ ² = C ₂ ² r ² cos2φ
Differentiate the quadratic term in the radial direction. If the differential in the radial direction is Z′r,
Z′r = (∂Z / ∂r) = C · 2r cos 2φ (13)
It becomes. Also, the second order term is differentiated in the circumferential direction. If the circumferential differential is Z′φ,
Z′φ = (∂Z / ∂φ) = − 2C · r ² sin2φ (14)
It becomes.

In the above, when least square fitting is performed with Z ′ (r _N ) and r _N obtained from each point image, but φ is included, ∂Z / ∂r, r, φ is used to obtain the coefficient C (13 There are two possible methods: fitting with equation (1) and fitting with equation (14) using 用 い Z / ∂φ, r, φ.

  Note that ∂Z / ∂r and ∂Z / ∂φ are values obtained from actual detection results, and r and φ are values known in advance.

  Here, since there are many cases where the Zernike coefficient C is usually calculated using the equation (13), only the case of the equation (13) will be considered below.

The equation for obtaining the least square fitting of equation (13) is as follows.

If the equation (15) is partially differentiated by C,

It becomes.

Similar to the equation (10), considering the radial random error ΔZr and only considering the case of r = r ₁ and φ = φ ₁ ,
_{(Z'r (r 1) + ΔZr} -2C · r 1 cos2φ1) (- 2r 1 cos2φ 1) = 0
... (17)
It becomes.

  From the equation (17), the following equation (18) is obtained.

C ₂ ² = (Z′r (r ₁ ) / 2r ₁ cos 2φ ₁ ) + ΔZr / 2r ₁ cos 2φ ₁
... (18)
From the equation (18), the relative contribution of the radial random error ΔZr to the coefficient determination of the term of r ² cos2φ that is the second-order term of the Zernike polynomial is ΔZr / 2rcos2φ. As shown in FIG. 5, in the 1 / 2rcos2φ graph, the points at φ = 45 °, 135 °, 225 °, and 315 ° are maximized, and information on the angle is almost dominant.

  At locations other than the local maximum, r is in the denominator, so that the larger r is, the smaller the contribution of random error ΔZr is.

In order to obtain a point image in which the contribution of the random error ΔZr is entirely uniform in the above r ² cos 2φ, for example, an arrangement as shown in FIG. 6 can be considered.

In the example shown in FIG. 6, for example, the radius r = r ₁ without placing the point images Qa and Qb at the positions of 45 °, 135 °, 225 °, and 315 ° where the contribution of the random error is maximum and diverges. Then, point images Qa are arranged at positions of 0 °, 90 °, 180 °, and 270 °, and when r ₂ = 3r ₁ , double the number of points on the circumference of r ₁ on the circumference of r _2. An image Qb is arranged.

In this example, the total contribution of random error ΔZr of each point image Qa on the circumference of radius r ₁ and the total contribution of random error ΔZr of each point image Qb on the circumference of radius r ₂ (3r ₁ ). Is equal to the contribution of the random error ΔZr of the point image Qa on the circumference of the radius r ₁ to the contribution of the random error ΔZr of one point image Qb on the circumference of the radius r _2. It may be 1/2.

That is, (1 / 2r ₁ cos2φ ₁ ) × 1/2 = 1 / 2r ₂ cos2φ ₂ may be satisfied.

Substituting r ₂ = 3r ₁ in this equation, 1 / 4r ₁ cos 2φ ₁ = 1 / 6r ₂ cos 2φ ₂
It becomes.

Therefore, φ ₂ = (1/2) cos ⁻¹ ((2/3) cos 2φ ₁ )
= 0 ° ± 24.095 ...
It becomes.

This indicates that the point image Qb only needs to be in the direction of ± 24.095 ° with respect to the radial direction of each point image Qa and at a position 3r ₁ from the center position O.

In the case of the arrangement of the point images Qa and Qb shown in FIG. 6, the contribution of the random error ΔZr when determining the coefficient of the term of r ² cos2φ is that the inner circumference (r ₁ circumference) and the outer circumference (r ₁ circumference) 3r ₁ = r ₂ (circumference), and this is equivalent to the case where it is considered as a contribution of random error exerted by one circumference.

  Therefore, if the lens arrays Qa1 and Qb2 are arranged as shown in FIG. 6A, the point images Qa and Qb are obtained as shown in FIG. 6, and the Zernike coefficient C to the inner circumference and the outer circumference is obtained. The contribution of the random error ΔZr is the same, and the contribution ratio of the error to the wavefront aberration calculation is the same for the inner circumference and the outer circumference. For this reason, accurate wavefront aberration can be obtained, and the astigmatic axis can be obtained accurately.

That is, the arrangement of the lens arrays Qa1 and Qb2 shown in FIG. 6A suppresses the measurement error of the specific term (r ² cos2φ term) as much as possible when the wavefront aberration is developed by a predetermined polynomial (for example, Zernike polynomial). It has been optimized.

  In the above embodiment, the Zernike coefficient C is obtained by differentiation in the radial direction, but the wavefront aberration in the circumferential direction may be obtained by differentiating in the circumferential direction to obtain the Zernike coefficient C. That is, the refractive power may be obtained by calculating the circumferential wavefront aberration by calculating the circumferential deviation of each point image. Further, the circumferential wavefront aberration obtained here may be displayed on the display unit 1071.

In each of the above-described embodiments, the case where the lens arrays are arranged circumferentially has been described. However, a large number of them are arranged in a lattice shape or at random, and depending on the purpose, for example, as shown in FIGS. 4A and 6A A lens array to be arranged may be extracted, a wavefront aberration may be obtained from a point image position of the extracted lens array, and a refractive power, an astigmatic axis, and the like may be calculated from the wavefront aberration.
[Fourth embodiment]
The ophthalmologic apparatus 10 shown in FIG. 7 illuminates (irradiates) the measurement light beam (first measurement light) to the fundus oculi Ef of the eye E and receives the wavefront of the measurement light beam reflected by the fundus oculi Ef to receive the eyeball of the eye E An eyeball wavefront aberration measuring optical system 100 for measuring the wavefront aberration of the eye, and projecting (irradiating) ring pattern light (second measurement light) to the cornea Ec of the eye E and receiving the ring pattern light reflected by the cornea Ec The corneal wavefront aberration measuring optical system 200 that measures the aberration of the cornea Ec, the anterior segment illumination optical system 50 that illuminates the anterior segment of the eye E, the alignment observation optical system 60, and the eye E to be aligned are aligned. An XY alignment optical system 70 for detection and a fixation optical system 80 for fixing the eye E to be examined are provided.
[Ocular wavefront aberration measurement optical system]
The ocular wavefront aberration measurement optical system 100 includes a measurement illumination optical system (illumination optical system) 20 that irradiates the fundus Ef of the eye E with a spot light as an illumination light beam (measurement light beam: first measurement light), and a fundus Ef. It has a light receiving optical system (wavefront measuring system) 30 for receiving the reflected light beam by an area sensor (first light receiving element) 31.
[Measurement illumination optical system]
The measurement illumination optical system 20 includes a measurement light source 21, a condenser lens 22, a polarization beam splitter 23, a dichroic mirror 24, a dichroic mirror 25, and an objective lens 26. In the measurement illumination system 20, a polarizing beam splitter 23 and dichroic mirrors 24 and 25 are disposed between the condenser lens 22 and the objective lens 26.

  The polarization beam splitter 23 includes a dichroic mirror that reflects the S-polarized component of the illumination light beam and transmits the P-polarized component of the reflected light beam from the fundus oculi Ef, which will be described later.

  The dichroic mirror 24 is configured by a wavelength selective mirror that reflects an illumination light beam and a reflected light beam and transmits a fixation light beam described later.

  The dichroic mirror 25 is configured by a dichroic mirror that reflects an illumination light beam, a reflected light beam, and a fixation light beam and transmits an observation light beam, which will be described later.

The measurement light source 21 is an SLD (super luminescence diode) that emits near-infrared light (first measurement light), and can be moved along the optical axis direction by the light source moving means 41.
The measurement light source 21 may be a laser or LED.
[Light receiving optical system]
The light receiving optical system 30 includes an area sensor 31, a Hartmann plate 32, a lens 33, a lens 34, a reflecting mirror 35, a polarizing beam splitter 23, dichroic mirrors 24 and 25, and an objective lens 26.

  In the light receiving optical system 30, the optical system from the eye E to the polarization beam splitter 23 is the same as the optical system of the measurement illumination optical system 20.

  The reflecting mirror 35 plays a role of making the optical axis of the reflected light beam from the fundus oculi Ef parallel to the direction of the optical axis of the illumination light beam emitted from the measurement light source 21. That is, in the light receiving optical system 30, the reflected light beam from the retina (fundus) Ef of the eye E to be inspected illuminated by the measurement illumination optical system 20 is reflected by the dichroic mirror 24 and the dichroic mirror 25 through the objective lens 26, and the polarized beam. The light is transmitted through the splitter 23 and reflected by the reflecting mirror 35, thereby leading to the measurement optical axis on which the lens 33, the lens 34, and the Hartmann plate 32 are disposed.

  The Hartmann plate 32 has a plurality of lens arrays (not shown) arranged on a plurality of concentric circles, like the Hartmann plate 1032 shown in FIG.

  The lens 33 converts the reflected light beam that has passed through the lens 34 into a parallel light beam and guides it to the Hartmann plate 32.

  The Hartmann plate 32 has a plurality of microlenses such as a micro Fresnel lens disposed in a plane orthogonal to the optical axis, and thereby divides a reflected light beam (parallel reflected light beam) from the fundus oculi Ef into a plurality of divided light beams. Then, the light is condensed on the light receiving surface of the area sensor 31.

  The area sensor 31 receives a plurality of divided light beams and outputs a light reception signal S4 corresponding to the amount of light received by each divided light beam. A wavefront aberration is obtained based on the light reception signal S4 from the area sensor 31. Analysis based on the change of the wavefront aberration (the amount of movement of each bright spot on the light receiving surface of the area sensor 31 with respect to the ideal wavefront) (Zernike analysis is performed based on the tilt angle of the light beam obtained by the area sensor 31). Thus, the optical characteristics (refraction state, aberration amount, etc.) of the eye E are calculated.

  The sensor unit 36 including the Hartmann plate 32 and the area sensor 31 is movable along the optical axis direction and is moved in the optical axis direction by the sensor moving means 42.

  According to the sensor moving means 42 and the light source moving means 41, the measurement light source 21, the retina (fundus) Ef of the eye E to be examined and the area sensor 31 (its light receiving surface) are substantially conjugated according to the refractive power of the eye E to be examined. Each is driven so as to have a positional relationship. As a method for such movement, the interval between bright spots on the area sensor 31 when the eye E of the “0” diopter (hereinafter referred to as “0” D) is measured in advance is stored and actually measured. What is necessary is just to move to the position where the bright spot interval on the area sensor 31 at the time of measuring the eye E to be examined substantially coincides with the stored interval.

In this embodiment, the measurement illumination optical system 20 and the light receiving optical system 30 are optically configured so that the movement amount of the measurement light source 21 and the movement amount of the sensor unit 36 are equal, and the measurement light source 21, the sensor unit 36, Are linked, and the light source moving means 41 and the sensor moving means 42 are configured as a single optical system moving means (not shown) driven by a single drive source (for example, a motor). Further, as will be described later, the target moving means 43 is also moved by a single optical system moving means. These optical system moving means are driven and controlled by a movement control signal S3 from the drive unit 14 (see FIG. 8).
[Cornea wavefront aberration measurement optical system]
The corneal wavefront aberration measurement optical system 200 includes an anterior ocular segment illumination optical system 50 that illuminates the anterior ocular segment, and a light receiving optical system (alignment observation optical system) 60 that receives reflected light reflected by the anterior ocular segment. Yes.
[Anterior illumination optical system]
The anterior ocular illumination optical system 50 is used for measuring the curvature of the cornea Ec of the eye E and Z alignment for detecting the working distance between the eye E and the device, and includes a placido ring pattern plate 51 and a pair of light sources ( LED) 52 and a pair of collimator lenses 53.
[Placido ring pattern board]
As shown in FIG. 9, the placido ring pattern plate 51 includes a plurality of ring patterns 54 formed concentrically so as to transmit light and surround the objective lens 26 (centering on the optical axis of the objective lens 26). .. And a pair of openings 57.

  The pair of openings 57 are provided on the ring pattern 55 on a straight line passing through the center of the ring pattern 55 (perpendicular to the optical axis of the objective lens 26). The interval between the center positions is set equal.

  A plurality of LEDs (not shown) are arranged along the ring patterns 54, 55, 56... On the back surface (objective lens 26 side) of the placido ring pattern plate 51, and the placido ring pattern plate 51 is formed by the plurality of LEDs. The cornea Ec of the eye E is illuminated with a ring-shaped light emission pattern by a light beam (second measurement light) that is illuminated and transmitted through the ring patterns 54, 55, 56,.

  The light source LED 52 is provided on the back side of the placido ring pattern plate 51 corresponding to each opening 57.

  The collimator lens 53 illuminates the opening 57 of the placido ring pattern plate 51 with the light emitted from the light source LED 52 as a parallel light, and the parallel light that has passed through the opening 57 illuminates the cornea Ec of the eye E.

  As described above, the anterior segment illumination optical system 50 illuminates the cornea Ec as a bright spot by the pair of light source LEDs 52 in addition to the ring-shaped light emission pattern. This light beam is reflected by the cornea Ec (the surface thereof), and the reflected observation light beam passes through the objective lens 26 and the dichroic mirror 25, passes through the alignment observation optical system 60 described later, and is placed on the area sensor 61 on the ring sensor 61. In addition to the projected images 54 ′, 55 ′, 56 ′, etc., a pair of bright spot images 57 ′ are formed by the pair of light source LEDs 52 (see FIG. 10). As described above, in the placido ring pattern plate 51, the pair of openings 57 are provided on the ring pattern 55, and the diameter dimension of the ring pattern 55 and the distance between the center positions of both openings 57 are set equal.

In the anterior segment illumination optical system 50, the illumination direction with respect to the cornea Ec is inclined with respect to the optical axis direction of the objective lens 26, and is provided on the back surface of the placido ring pattern plate 51 as viewed in the optical axis direction. The emission position of the LED and the emission position of the light source LED 52 are set differently. For this reason, when viewed as an image formed on the area sensor 61 (its light receiving surface) by the anterior segment illumination optical system 50, when the Z alignment matches, the diameter dimension RL of the ring-shaped projection image 55 ' The distance DL between the center positions of the pair of bright spot images 57 ′ becomes equal (see FIG. 10).
Further, when viewed as an image formed on the area sensor 61 (its light receiving surface) by the anterior ocular segment illumination optical system 50, the distance DL between the center positions of the pair of bright spot images 57 ′ is set regardless of the change in the Z alignment. Although it does not change, the diameter dimension RL of the ring-shaped projection image 55 ′ changes according to the change in the Z alignment. From this, on the area sensor 61 (its light receiving surface), when the Z alignment does not match, the diameter dimension RL of the ring-shaped projection image 55 ′ and the distance DL between the center positions of the pair of bright spot images 57 ′ (See FIG. 11). For this reason, the diameter DL of the ring-shaped projection image 55 ′ formed on the area sensor 61 (its light receiving surface) by the anterior segment illumination optical system 50 and the distance DL between the center positions of the pair of bright spot images 57 ′. By moving the position of the apparatus relative to the eye E so as to be equal to each other, Z alignment that keeps the distance between the eye E and the apparatus constant can be executed.
[Alignment observation optical system]
The alignment observation optical system 60 includes an area sensor 61, an imaging lens 62, a relay lens 63, a half mirror 64, a dichroic mirror 25, and an objective lens 26. In the alignment observation optical system 60, as described above, the optical system from the eye E to the dichroic mirror 25 is the same as the optical system of the measurement illumination optical system 20.

The area sensor 61 is constituted by a CCD, for example. On the light receiving surface of the area sensor 61 (CCD), as described above, the ring-shaped projection images 54 ′, 55 ′, 56 ′ and the pair of bright spot images 57 ′ by the anterior segment illumination optical system 50, A bright spot image 71 ′ for XY alignment is formed by an XY alignment optical system 70 described later.
[XY alignment optical system]
The XY alignment optical system 70 includes an alignment light source 71, a lens 72, a reflecting mirror 73, a half mirror 64, a dichroic mirror 25, and an objective lens 26.

  The XY alignment optical system 70 converts the alignment light emitted from the alignment light source 71 into a parallel light beam by the lens 72, reflects it by the reflecting mirror 73, further reflects it by the half mirror 64, and passes through the dichroic mirror 25 and the objective lens 26. The E cornea Ec is illuminated.

  Here, the area sensor 61 is disposed so as to be substantially conjugate with a virtual image (Purkinje image) formed by the curvature of the cornea Ec, and by illuminating the cornea Ec from the XY alignment optical system 70, the cornea Ec (that The light beam reflected on the surface) (hereinafter referred to as the adjustment light beam) passes through the objective lens 26, the dichroic mirror 25, the half mirror 64, and the relay lens 63 and is focused on the area sensor 61 by the imaging lens 62. The bright spot image 71 ′ is formed (see FIG. 10).

In the XY alignment optical system 70, as shown in FIG. 10, when the corneal apex of the eye E coincides with the optical axis of the alignment observation optical system 60, the bright spot image 71 ′ for XY alignment is displayed as an area sensor. 61 (its light receiving surface) is set so as to be located at the center. Here, when the corneal apex of the eye E to be examined moves in a plane orthogonal to the optical axis of the alignment observation optical system 60, the area sensor 61 (its light reception) Plane). Therefore, the XY alignment is executed by moving the apparatus main body with respect to the eye E so that the bright spot image 71 ′ for XY alignment is positioned at the center on the area sensor 61 (its light receiving surface). be able to.
[Fixed optical system]
The fixation optical system 80 is an optical system that projects a fixation target (fixation chart) for fixation or cloud fog on the eye E, and includes a light source 81, a lens 82, and a fixation chart (fixation chart). Standard) 83, lens 84, lens 85, reflecting mirror 86, dichroic mirror 24, dichroic mirror 25, and objective lens 26. As described above, in the fixation optical system 80, the optical system from the eye E to the dichroic mirror 24 is common to the measurement illumination optical system 20.

  The reflecting mirror 86 emits a light beam (hereinafter referred to as a fixation light beam) emitted from the light source 81 and transmitted through the lens 82, the fixation target 83, the lens 84, and the lens 85 from the measurement light source 21 in the measurement illumination optical system 20. It has the role of matching the direction of the optical axis of the light beam and the direction of the optical axis of the reflected light beam toward the area sensor 31 in the light receiving optical system 30. The light source 81 is a light source that emits light having a wavelength in the visible region (hereinafter simply referred to as visible light), and a tungsten lamp or LED is used. The light source 81 has a variable amount of light. As this variable range, at least the brightness equivalent to that in the daytime environment from the amount of light that can irradiate the eye E to observe the fixation target image with the same brightness as that in the nighttime environment. The amount of light that can be irradiated is also included. Therefore, the fixation optical system 80 (its light source 81) functions as a visible light illuminating unit that illuminates the eye E with visible light along the optical axis of the measurement optical system.

  In this embodiment, the light source 81 has four levels of brightness ranging from the amount of light that can irradiate the same brightness as that in a nighttime environment to the amount of light that can irradiate the same brightness as in a daytime environment. Switching is possible.

  Although not shown, the fixation target 83 has a landscape or radiation pattern, and is illuminated from behind by a light beam emitted from the light source 81. In this fixation optical system 80, visible light (hereinafter referred to as fixation light flux) emitted from a light source 81 and transmitted through a fixation target 83 is transmitted through a lens 84 and a lens 85, reflected by a reflecting mirror 86, and dichroic mirrored. 24, reflected by the dichroic mirror 25, and incident on the eye E through the objective lens 26, thereby causing the fixation target 83 to be projected onto the retina (fundus) Ef and the fixation target image on the eye E to be examined. Make it visible. As a result, the line of sight of the eye E is fixed to the fixation target 83.

  The target unit 87 including the light source 81, the lens 82, and the fixation target 83 of the fixation optical system 80 can be moved along the fixation optical axis of the fixation optical system 80 by the target moving means 43. Yes. The target moving means 43 is driven so as to move the fixation optical system 80 to a position where the image of the fixation target 83 can be formed on the retina (fundus) Ef (position where the focus is in focus). In addition, in the scene where the eye E is measured, the target moving means 43 performs cloud fog that moves to a position where the focus cannot be achieved in order to eliminate the influence of the adjustment of the eye E.

The target moving unit 43 is driven by a single optical system moving unit that drives the sensor moving unit 42 and the light source moving unit 41. That is, the light source moving unit 41, the sensor moving unit 42, and the target moving unit 43 are driven by a single drive source (for example, a motor). The target unit 87 is driven and controlled by a movement control signal S3 to the target moving means 43, that is, the optical system moving means.
[Control system]
FIG. 8 shows the configuration of the control system of the ophthalmologic apparatus 10. In FIG. 8, 11 is a control calculation unit, 12 is an input unit (operation unit), 13 is a display unit (display means: monitor), and 14 is a drive unit.

  The control calculation unit 11 receives a light reception signal S4 from the area sensor 31 of the light reception optical system 30, a light reception signal S7 from the area sensor 61 of the alignment observation optical system 60, and an operation signal from the input unit 12.

  The control calculation unit 11 includes an input information processing unit 11a that appropriately processes the received light reception signals S4 and S7, a signal processed by the input information processing unit 11a, an operation signal from the input unit 12, and the like. Processed by the drive control unit 11b for controlling the lighting of the light sources 21, 52, 71, 81 of 20, 50, 70, and 80, the control of the optical system moving means, and the drive control of the drive unit 14, and the input information processing unit 11a An analysis processing section (eyeball wavefront aberration calculating means: corneal wavefront aberration calculating means: simulation means) 11c for calculating the wavefront aberration and refractive power of the eye E based on the received light signals S4 and S7, an image display control section 11d, It has a storage unit 11e that stores various data and an image forming unit 11f that forms an image such as a wavefront aberration map.

  The analysis processing unit 11c uses the measured wavefront aberration and other measurement data to determine various optical characteristics related to the eye E, such as a point spread coefficient (PSF), an MTF (Modulation Transfer Function) indicating transfer characteristics of the eye, and the pupil. Calculate diameter, contrast sensitivity, etc. And the analysis process part 11c functions as a pupil diameter size measurement means. Further, the analysis processing unit 11c outputs signals or other signals / data corresponding to the calculation results to a drive control unit 11b that controls the optical system and the electric control system, an image display control unit 11d, and a storage unit 11e. Output as appropriate.

  The image display control unit 11d is an image of the cornea Ec of the eye E based on signals from the input information processing unit 11a (light reception signal S4 from the light reception optical system 30, light reception signal S7 from the alignment observation optical system 60, and the like). Alternatively, a signal for displaying an image showing a wavefront or the like is output to the display unit 13. Further, the image display control unit 11d outputs to the display unit 13 a measurement result, a calculation result, an analysis result, and a signal for displaying a window for an operator to input and instruct data.

  The storage unit 11e stores data relating to the eye E, data used for wavefront aberration calculation, setting data for measurement, and the like. That is, information transmitted from the input information processing unit 11a, the drive control unit 11b, and the analysis processing unit 11c is stored as appropriate, and the stored information is stored in the input information processing unit 11a, the drive control unit 11b, the analysis processing unit 11c, and the image. It is appropriately pulled out in response to a request from the display control unit 11d. In addition, the storage unit 11e stores a control program for performing measurement automatically.

  The image forming unit 11f creates a map or a graph from the wavefront aberration obtained by the analysis processing unit 11c.

The input unit 12 is a switch, a button, a keyboard, or the like for an operator to input various input signals such as predetermined settings, instructions, and data. Here, it is assumed that a pointing device or the like for supporting buttons, icons, positions, areas, and the like displayed on the display unit 13 is included. The input unit 12 outputs an operation signal corresponding to the operation performed by itself to the control calculation unit 11. In the first embodiment, the input unit 12 includes a light amount changeover switch 12a and a measurement start switch 12b. The light amount changeover switch 12a changes the light amount of the light source 81 from a light amount that can irradiate a brightness equivalent to that in a set nighttime environment to a light amount that can irradiate a brightness equivalent to that in a daytime environment. It is for switching to four levels of brightness, and the measurement start switch 12b is for executing various measurements.

  The display unit 13 displays measurement results, calculation results, analysis results, a window for an operator to input and instruct data, an image of the eye E to be examined, and the like. The display unit 13 performs display as appropriate under the control of the control calculation unit 11.

For example, based on the light reception signal S4 from the area sensor 31 input to the control calculation unit 11, the drive unit 14 is based on the measurement light source 21 (light source moving means 41) of the measurement illumination optical system 20 and the sensor unit of the light reception optical system 30. 36 (sensor moving means 42) and an optical system moving means (not shown) for integrally moving the target unit 87 (target moving means 43) of the fixation optical system 80 in the optical axis direction are driven. The drive unit 14 drives the optical system moving unit by outputting a movement control signal S3 to the optical system moving unit.
[Operation]
Next, the operation of the ophthalmologic apparatus 10 of the above embodiment will be described.

  First, the light source 81 of the fixation optical system 80 is caused to emit light to fix the eye E, and the alignment light source 71 of the XY alignment optical system 70 is caused to emit light. The alignment light emitted from the alignment light source 71 is converted into a parallel light beam by the lens 72, reflected by the reflecting mirror 73, further reflected by the half mirror 64, and the cornea Ec of the eye E to be examined via the dichroic mirror 25 and the objective lens 26. Illuminate.

  The adjustment light beam reflected by the cornea Ec (the surface thereof) passes through the objective lens 26, the dichroic mirror 25, the half mirror 64, and the relay lens 63, and is condensed on the area sensor 61 by the imaging lens 62, and the bright spot image 71 is obtained. ′ Is formed (see FIG. 10).

  The bright spot image 71 ′ is displayed on the display unit 13 as in FIG. 10, and the bright spot image 71 ′ is the center position on the area sensor 61 (its light receiving surface), that is, the mark position displayed on the display unit 13 (see FIG. XY alignment is performed by moving the apparatus main body with respect to the eye E to be positioned so that it is located at a position not shown.

  Then, the pair of light sources 52 of the anterior segment illumination optical system 50 and a plurality of LEDs (not shown) are caused to emit light. The placido ring pattern plate 51 is illuminated by the light emission of the plurality of LEDs, and a ring-shaped light emission pattern is projected onto the cornea Ec of the eye E to be examined.

  The observation light beam reflected by the cornea Ec passes through the objective lens 26 and the dichroic mirror 25, passes through the alignment observation optical system 60, and is projected onto the area sensor 61 in the form of ring-shaped projection images 54 ', 55', 56 '. In addition to the pair of light source LEDs 52, a pair of bright spot images 57 'are formed. The display unit 13 displays the bright spot image 57 ′ and the ring-shaped projection images 54 ′, 55 ′, 56 ′,.

  The examiner sets the apparatus main body for the eye E so that the diameter dimension RL of the ring-shaped projection image 55 ′ displayed on the display unit 13 is equal to the distance DL between the center positions of the pair of bright spot images 57 ′. The Z alignment is performed by moving the position back and forth.

  Next, a case where wavefront aberration is measured will be described.

  As shown in FIG. 7, the light source 81 of the fixation optical system 80 is turned on with a predetermined brightness, and the eye E is observed by the eye E to be examined. In this state, the corneal apex of the eye E to be examined and the measurement optical axis of the apparatus main body (the optical axis of the objective lens 26) are made to coincide with each other by XY alignment, and the distance from the corneal apex of the eye E to the apparatus main body is made by Z alignment. Keep constant. Thereafter, the measurement light source 21 of the measurement illumination optical system 20 is moved to the reference position by the optical system moving means, and the measurement light source 21 is turned on. At this time, the sensor unit 36 of the light receiving optical system 30 and the target unit 87 of the fixation optical system 80 are also moved integrally by the optical system moving means, and thus set as the reference position.

  At this reference position, the refractive state of the eye E is temporarily measured, and the measurement light source 21 and the light receiving optical system 30 of the measurement illumination optical system 20 are positioned at positions where the refractive power of the eye E is canceled based on the result of the temporary measurement. Are moved, and the refractive state of the eye E is measured again at that position. As a result of this re-measurement, when the sensor unit 36 of the light receiving optical system 30 is in a position that substantially cancels the refractive power of the eye E, the target unit 87 of the fixation optical system 80 is moved to the plus side. Cloud the fixation image. In this state, the refractive state and wavefront aberration of the eye E are measured.

  In this measurement, in the measurement illumination optical system 20, the light beam emitted from the measurement light source 21 and transmitted through the condenser lens 22 is reflected by the polarization beam splitter 23, the dichroic mirror 24, and the dichroic mirror 25 and onto the optical axis of the objective lens 26. Then, the fundus oculi Ef of the eye E is illuminated. Assuming that this is an illumination light beam Li, as shown in FIG. 12, it enters the eye E through the objective lens 26 as a light beam having an extremely small diameter, and illuminates a minute region (spot light) of the fundus oculi Ef. Then, at the fundus oculi Ef, the illumination light beam Li is reflected, and the light beam that has passed through the pupil Ep (inward of the iris Ei) of the reflected light beam is directed toward the objective lens 26.

  Assuming that this is a reflected light beam Lr, the reflected light beam Lr is guided to the light receiving optical system 30 (see FIG. 7) through the objective lens 26 as shown in FIG. That is, the reflected light beam Lr is reflected by the light receiving optical system 30 through the objective lens 26, the dichroic mirror 24 and the dichroic mirror 25, and transmitted through the polarization beam splitter 23 and reflected by the reflecting mirror 35. The light travels toward the Hartmann plate 32, passes through the Hartmann plate 32, is divided into a plurality of divided light beams, and is condensed on the light receiving surface of the area sensor 31.

  The area sensor 31 receives each divided light beam and photoelectrically converts it, and outputs a received light signal S4 corresponding to the received light amount of each divided light beam to the control calculation unit 11. The control calculation unit 11 can obtain wavefront aberration (eyeball wavefront aberration) from the data acquired by the light reception signal S4 in the analysis processing unit 11c, and changes in the wavefront aberration (for each bright spot on the light receiving surface of the area sensor 31). By analyzing based on the movement amount with respect to the ideal wavefront, it is possible to calculate the optical characteristics (the refraction state, the aberration amount, etc.) of the eye E.

  Like the Hartmann plate 1032 shown in FIG. 2, the Hartmann plate 32 has a plurality of lens arrays (not shown) arranged on a plurality of concentric circles, so that it is accurate as in the first embodiment. Wavefront aberration can be determined.

  Here, as shown in FIG. 12, the calculated refraction state is an actual optical state in an area (a hatched area (reference symbol Ar) in FIG. 12) where the reflected light beam Lr is transmitted through the eye E. All elements are included.

  The measurement of the wavefront aberration is performed 10 times per second, the standard deviation of the measured wavefront aberration is obtained, and the standard deviation is compared with a preset reference value as shown in FIG. 13 (step 1). When the standard deviation is larger than the reference value, that is, when it is determined that the eye is dry eye, the process proceeds to step 2.

  For the wavefront aberration of each measurement, one RMS (root mean square) value is calculated for the entire eyeball, and this value is used as the wavefront aberration.

  In Step 2, the image forming unit 11f creates maps M1 to M10 of the measured wavefront aberrations, and displays the maps M1 to M10 on the display unit 13 as shown in FIG. Further, the analysis processing unit 11c simulates how the Landolt ring looks to the subject from each wavefront aberration, and displays the simulated Landolt rings K1 to K2 on the display unit 13. The values of wavefront aberration in the maps M1 to M10 are H1 <H2 <H3 <H4. Also, the Landolt ring becomes blurred as the wavefront aberration increases.

  The display unit 13 displays a graph G1 indicating the wavefront aberration (RMS value) with respect to the number of measurements. This graph G1 is also created by the image forming unit (graph creating means) 11f.

  Further, based on the ring-shaped projection images 54 ′, 55 ′, 56 ′,... Formed on the area sensor 61, the analysis processing unit 11c of the calculation control unit 11 obtains the wavefront aberration of the cornea Ec for each measurement. The image forming unit 11f creates a graph G2 indicating the wavefront aberration of the cornea Ec with respect to the number of measurements, and this graph G2 is displayed on the display unit 13 as shown in FIG.

  If NO is determined in step 1, that is, if the standard deviation is equal to or smaller than the reference value, that is, if it is determined that the eye is not dry eye, the process proceeds to step 3.

  In Step 3, the image forming unit 11f creates a wavefront aberration map for each measurement based on the wavefront aberration of the cornea Ec obtained by the analysis processing unit 11c of the control calculation unit 11, and the maps M1c to M10c are shown in FIG. Is displayed on the display unit 13 as shown in FIG.

  As described above, when it is determined that the eye is not dry eye, the cornea wavefront aberration maps M1c to M10c whose wavefront aberrations change with time are displayed on the display unit 13, and thus the maps M1c to M10c are displayed. If the change with time of the wavefront aberration is small, it can be recognized more clearly that it is not dry eye. That is, confirmation that it is not dry eye can be obtained. Note that the cornea wavefront aberrations are exaggerated in the maps M5c to M10c shown in FIG.

  In the above embodiment, the standard deviation and the reference value are compared in Step 1, but the average value of the wavefront aberration may be compared with the reference value for determination.

  The present invention is not limited to the above-described embodiments, and design changes and additions are permitted without departing from the spirit of the invention according to each claim of the claims.

1010 Ophthalmology apparatus 1020 Fundus illumination optical system (illumination optical system)
1030 Wavefront measurement optical system (wavefront measurement system)
1032 Hartmann plate 1032A to 1032E Lens array 1033 Light receiving unit 1050 Observation optical system 1052 Light receiving unit 1070 Calculation control unit E Eye to be examined Ef Fundus Ea Anterior eye unit

Claims (8)

A Hartmann plate having an illumination optical system that illuminates the fundus of the eye to be examined, a plurality of lens arrays that divide the reflected illumination light reflected from the fundus into a plurality of light beams, and a light reception that receives the divided light beams divided by the Hartmann plate An ophthalmologic apparatus comprising a wavefront measuring system having a section,
Select a plurality of lens arrays at a position suitable for an arithmetic expression for obtaining a measurement value from a plurality of lens arrays of the Hartmann plate,
An ophthalmologic apparatus characterized in that wavefront aberration is obtained from a point image of a light receiving unit corresponding to the plurality of selected lens arrays, and optical characteristics of the eye to be examined are measured based on the wavefront aberration. A Hartmann plate having an illumination optical system that illuminates the fundus of the eye to be examined, a plurality of lens arrays that divide the reflected illumination light reflected from the fundus into a plurality of light beams, and a light reception that receives the divided light beams divided by the Hartmann plate An ophthalmologic apparatus comprising a wavefront measuring system having a section,
An ophthalmologic apparatus, wherein a plurality of lens arrays formed on the Hartmann plate are arranged on a plurality of circumferences.   The ophthalmologic apparatus according to claim 2, wherein an optical characteristic of the eye to be examined is measured based on a point image of the light receiving unit formed by the plurality of lens arrays. Obtain wavefront aberration from all point images of the light receiving unit, obtain the optical characteristics of the eye to be examined based on the wavefront aberration,
Alternatively, the wavefront aberration for each circumference is obtained from the point image for each circumference, and the optical characteristics of the eye to be examined are measured for each circumference based on the wavefront aberration for each circumference. The ophthalmic device described.   The ophthalmologic apparatus according to claim 4, wherein a measurement result of optical characteristics of the eye to be examined is provided to the subject.   The optical characteristic of the eye to be examined is measured from the shape of a line formed by connecting each point image so as to surround the center position of the light receiving section or the center position of the pupil image formed on the light receiving section. The ophthalmic apparatus according to claim 2.   The ophthalmologic apparatus according to claim 1 or 3, wherein a wavefront aberration in a circumferential direction is obtained from a deviation from a reference position of each point image.   The ophthalmic apparatus according to claim 1, wherein the arrangement of the lens array is optimized so as to suppress a measurement error of a specific term as much as possible when the wavefront aberration is developed by a predetermined polynomial.