JP3043776B2 - Eye refractive power measuring device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an eye-refractive-power measuring apparatus, and particularly to an eye-refractive-power measuring apparatus that is convenient when selecting a trial lens.

2. Description of the Related Art Conventionally, when a measured value displayed by an eye-refractive-power measuring apparatus has a refractive power having a cylindrical refractive power, there are three display methods: a minus mode, a plus mode, and a mixed mode.
It is known that there is a mode. In the conventional eye refraction measuring device, there is no display that selectively uses these, and three modes of a plus mode, a minus mode, and a mixed mode set by a mode conversion switch are selectively selected.

On the other hand, in selecting a trial lens for selecting eyeglasses, it is necessary to select a combination of a spherical lens and a cylindrical lens having as small a refractive index as possible to minimize aberration.

Therefore, in selecting a trial lens, after the measurement was completed, it was necessary to manually convert the measured values printed out to obtain an optimum combination of a spherical lens and a cylindrical lens.

[Problems to be Solved by the Invention] In the conventional method as described above, not only the selection takes time but also the anxiety factor that the selection of the examiner is wrong could not be solved.

The present invention has been devised in view of the above-described drawbacks, and has as its technical object to provide an eye refractive power measuring apparatus that allows a trial lens to be selected immediately and accurately.

[Means for Solving the Problems] The present invention is characterized by having the following configuration in order to solve the above problems.

(1) When an eye refractive power measuring device that projects a measurement target on the fundus of the eye to be examined and obtains a refractive power value based on the position of the target image uses concave and convex cylindrical lenses. Calculating means for obtaining two combinations of a spherical lens and a cylindrical lens corresponding to the refractive power value, and selecting means for selecting a combination having a smaller absolute value of the refractive power of the spherical lens from the two combinations. And display means for displaying a combination of the selected spherical lens and cylindrical lens.

(2) In an eye refractive power measuring device capable of projecting a measurement target to the fundus of an eye to be examined and obtaining a refractive power value based on the position of the target image, a spherical refractive power reading minus from the refractive power value. A first calculating means for calculating a cylindrical refractive power and an astigmatic axis angle; a second calculating means for calculating a positive reading spherical refractive power, a cylindrical refractive power and an astigmatic axis angle from the refractive power value; The third calculating means for calculating the sum of the absolute values of the spherical refractive power and the cylindrical refractive power obtained by the calculating means is compared with the sum of the two absolute values, and the smaller value is selected. It is characterized by comprising selection means, and display means for displaying the spherical power, cylindrical power, and astigmatic axis angle selected by the selection means.

(3) When a concave or convex cylindrical lens is used in an eye-refractive-power measuring apparatus that projects a measurement target on the fundus of the subject's eye and detects the position of the target image to measure a refractive power value. Calculating means for obtaining two combinations of a spherical lens and a cylindrical lens corresponding to the refractive power value, and selecting means for selecting a combination having a smaller absolute value of the refractive power of the spherical lens from the two combinations. And output means for outputting a combination of the selected spherical lens and cylindrical lens.

(4) An eye refractive power measuring device that projects a measurement target on the fundus of the eye to be inspected, detects the position of the target image, and measures the refractive power value. ,
First calculating means for calculating a cylindrical refractive power and an astigmatic axis angle; and a spherical reading power, a cylindrical refractive power, and a plus reading from the refractive power value;
A second calculating means for calculating the astigmatic axis angle; a third calculating means for calculating a sum of absolute values of the spherical refractive power and the columnar refractive power obtained by the two calculating means; Comparing the sum of the values, selecting means for selecting the smaller value, and output means for outputting the spherical power, cylindrical power, and astigmatic axis angle selected by the selecting means, I do.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 3 is an arrangement diagram of an optical system of the eye-refractive-power measuring apparatus according to the present invention, wherein 1 is a measuring light source having a wavelength in an infrared region;
Reference numerals 2 and 3 denote condensing lenses, 4 denotes a spot stop movable so as to be disposed at a position conjugate with the fundus of the eye 8 to be examined, 5 and 6 denote objective lenses, 7 and 9 denote beam splitters, 10 denotes mirrors,
11 and 12 are relay lenses, 13 is a strip-shaped corneal reflection removing mask arranged at a position conjugate with the cornea of the eye 8 to be examined, 14 is a moving lens that moves together with the spot stop 4, and 15 is an imaging lens. Reference numeral 16 denotes a light receiving element for measurement, which rotates around an optical axis in synchronization with the light source for measurement 1 and the corneal reflection removing mask 13. Reference numeral 17 denotes a first relay lens movable on the optical axis, and constitutes a fog mechanism. Reference numeral 18 denotes a second relay lens, reference numeral 19 denotes a target arranged at the focal position of the second relay lens 18, reference numeral 20 denotes a condenser lens, and reference numeral 21 denotes an illumination lamp.

The light energy emitted from the light source 1 is condensed from the cornea of the subject's eye 8 via the condenser lenses 2 and 3, the spot stop 4, and the objective lens 5, and reaches the fundus. On the other hand, the light from the illumination lamp 21 passes through the condenser lens 20 to project the target 19 onto the fundus of the eye 8 to fix the eye 8. The light reflected from the fundus is reflected by the mirror 10,
After passing through the relay lenses 11 and 12, an image is formed on the light receiving element 16 by the imaging lens 15. The light energy incident on the light receiving element 16 is supplied to the CPU 32 (FIG. 1) as a digital signal.

FIG. 1 is a block diagram showing a control system of the eye-refractive-power measuring apparatus of the present embodiment including the above-described measuring system 33.

A measurement switch 31 sends a measurement command to the CPU 32. The CPU 32 receives the instruction from the measurement switch 31 and
3 and performs various processes in response to a signal from the measurement system 33. Reference numeral 34 denotes a RAM from which each data can be written and read. 35 is a display unit, and 36 is a printer.

Next, the processing method of the present embodiment will be described based on the flowchart of FIG.

In step 1-1, the start switch for starting the measurement is pressed, and the process proceeds to step 1-2, where a series of measurements is performed, and the measurement data is sent to the CPU 32.

There are three types of display modes for indicating the eye refractive power: minus reading, plus reading, and mixed reading. Here, the trial lens is generally composed of a spherical lens and a columnar lens having no spherical component, and a desired power is created by combining these lenses and worn by a subject. At this time, two types of lens combinations can be considered depending on whether the cylindrical lens is concave or convex, but it is natural that it is better to combine lenses with a small refractive index so as to reduce the aberration of the trial lens.

Spherical power S ₁ read minus the measured data in step 1-3, the pillar surface power C _1, to calculate the astigmatic axis angle A _1.

In step 1-4, the mode conversion of the measured value is performed to calculate the positive reading spherical refractive power S ₂ , cylindrical refractive power C ₂ , and astigmatic axis angle A ₂ .

Here, a case where the combination of trial lenses is determined by taking an example will be considered. The following data are all negative readings, S is spherical power, C is column power, and A is astigmatic axis angle.

S + 3.00D, C−3.00D, A90 ° S + 0.25D, C−1.50D, A90 ° In the case of S + 1.50D, C−2.00D, A45 °, a + 3.00D spherical lens and −3.00 out of the trial lenses There is no choice of the columnar lens of D.
That is, if a plus reading is made, only a columnar lens of + 3.00D is sufficient, and this can reduce the aberration. In the case of the plus reading, the spherical lens is -1.25
D, the value of the columnar lens is + 1.50D, which indicates that it is better to keep the reading as negative. Similarly, in the case, it is better to convert to plus reading.

As can be seen from the above example, it can be seen that it is impossible to select a spherical and cylindrical trial lens as it is from the measurement data in only one mode.

Sum M ₁ of the absolute value of the step 1-5, respectively S ₁ and C _1,
Calculating a sum M ₂ of the absolute value of S ₂ and C _2.

In step 1-6 by comparing the size of M ₁ and M _2,
The smaller the better of M _1, the process proceeds to step 1-7. It should be noted that the S ₁
That the same results can be obtained by comparing the absolute value of S ₂ is a matter of course. The process proceeds to step 2-1 the smaller the direction of M _2.

In the present invention, when the measurement is completed in the eye-refractive-power measuring device, the measured data is automatically converted from a minus reading to a plus reading (or vice versa) by a microcomputer or the like in the device, and the optimum data is used when combining a trial lens. It automatically determines which reading the combination will read and displays it along with the measured values.

In the calculation, the sum of the absolute values of the spherical refractive power and the cylindrical refractive power is calculated from the two measurement data obtained by the mode conversion, and the reading of the smaller sum is displayed as an optimal combination.

Thus in step 1-7 to display the S _1, C _1, A ₁ as a trial lens data. The step 2-1 Show S _2, C _2, A ₂ as a trial lens data. Then, the process proceeds to step 1-8.

In step 1-8, the obtained trial lens data is printed out by the printer 36, and the process is terminated.

This printout can be performed simultaneously when the eye refractive power measuring device prints out the measurement data as it is.

Also, in a system ophthalmoscope in which an objective refractive power measuring device, a subjective refractive power measuring device, and a trial lens are placed on a table, LEDs are inserted into the trial lens rack, and LEDs near the trial lens to be selected. Can also be displayed by turning on.

[Effect] According to the eye-refractive-power measuring apparatus of the present invention, the trial lens can be immediately and accurately selected, and the optometric operation can be made simple and quick.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a control system of the eye refractive power measuring device of the present embodiment. FIG. 2 is a flowchart showing the operation of the embodiment. FIG. 3 is an optical system layout diagram of the eye refractive power measuring device according to the present invention. 31… Measurement switch 32… CPU 33… Measurement system 34… RAM 35… Display unit 36… Printer

Claims (4)

(57) [Claims] 1. An eye refractive power measuring apparatus which projects a measurement target to the fundus of an eye to be examined and obtains a refractive power value based on the position of the target image, using concave and convex cylindrical lenses. Calculating means for obtaining two combinations of a spherical lens and a cylindrical lens corresponding to the refractive power value at the time of performing the above, and selecting a combination having a smaller absolute value of the refractive power of the spherical lens from the two combinations. An eye-refractive-power measuring apparatus, comprising: selecting means; and displaying means for displaying the selected combination of the spherical lens and the cylindrical lens. 2. An eye-refractive-power measuring apparatus capable of projecting a measurement target to the fundus of an eye to be examined and obtaining a refractive power value based on the position of the target image, wherein the spherical surface is read from the refractive power value in a minus direction. First calculating means for calculating a refractive power, a cylindrical refractive power, and an astigmatic axis angle; and a spherical refractive power of a plus reading from the refractive power value;
A second calculating means for calculating the cylindrical refractive power and the astigmatic axis angle; and a third calculating means for calculating the sum of the absolute values of the spherical refractive power and the cylindrical refractive power obtained by the two calculating means, respectively. Selecting means for comparing the sum of the two absolute values and selecting the smaller value, and display means for displaying the spherical power, cylindrical power, and astigmatic axis angle selected by the selecting means. An eye-refractive-power measuring device, comprising: 3. An eye refractive power measuring apparatus for projecting a measurement target to the fundus of an eye to be examined and detecting a position of the target image to measure a refractive power value, wherein each of a concave and a convex cylindrical lens is used. Calculating means for obtaining two combinations of a spherical lens and a cylindrical lens corresponding to the refractive power value at the time of performing the above, and selecting a combination having a smaller absolute value of the refractive power of the spherical lens from the two combinations. An eye-refractive-power measuring apparatus, comprising: selecting means; and output means for outputting a combination of the selected spherical lens and cylindrical lens. 4. An eye-refractive-power measuring apparatus for projecting a measurement target to the fundus of an eye to be examined, detecting a position of the target image and measuring a refractive power value, wherein the spherical surface having a negative reading from the refractive power value is provided. A first calculating means for calculating a refractive power, a cylindrical refractive power, and an astigmatic axis angle; a second calculating means for calculating a positive reading spherical refractive power, a cylindrical refractive power, and an astigmatic axis angle from the refractive power value; The third arithmetic means for calculating the sum of the absolute values of the spherical power and the columnar refractive power obtained by the two arithmetic means and the sum of the two absolute values are compared. An eye-refractive-power measuring apparatus, comprising: selecting means for selecting; and output means for outputting the spherical refractive power, the cylindrical refractive power, and the astigmatic axis angle selected by the selecting means.