JP3015052B2 - Eye refractometer - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an eye refractometer used in, for example, an ophthalmic clinic.

[Related Art] In a conventional ophthalmic refractometer, alignment is performed while observing an anterior segment of the eye, and after confirming that the alignment is visually confirmed, an eye refraction measurement is performed by pressing a measurement button.

[Problems to be Solved by the Invention] However, in the above-mentioned conventional example, the timing of measurement may be missed in the case of an easily-moving eye such as an infant or a nystagmus patient. In some cases, the measurement is performed without positioning, causing a measurement error.

An object of the present invention is to provide an eye refractometer capable of solving the above-mentioned drawbacks of the conventional example and performing accurate eye refraction measurement without being affected by the state of the subject or the operation of the examiner. It is in.

[Means for Solving the Problems] In an eye refractometer according to the present invention for achieving the above object, a visual target that changes a visual target visibility by moving a visual target system member in an optical axis direction and performs diopter guidance. Marking means, a refractive power measuring means for projecting a light beam onto the fundus of the eye to be examined, and photoelectrically detecting a reflected light thereof to obtain an eye refraction value, and the target system for measuring a refractive power by the refractive power measuring means. Selecting means for allowing the examiner to select how to move the member.

[Effect] The eye refractometer having the above-described configuration includes a target means for moving the target system member in the optical axis direction to change the target diopter and perform diopter guidance, and projecting and reflecting the light flux on the fundus of the eye to be examined. A refractive power measuring means for photoelectrically detecting light to obtain an eye refraction value, and the movement of the target system member at the time of measuring the refractive power by the refractive power measuring means can be selected, so that the eye is not stable Consideration is given to the subject.

[Example] The present invention will be described in detail based on an illustrated example.

FIG. 1 shows a configuration diagram of an eye refractometer according to an embodiment of the present invention, in which an optical axis from a light source 1 that emits a visible light beam to an eye E to be examined.
On P1, a target 2, a lens 3,
4. A dichroic mirror 5 is provided. Optical axis P1
Optical axes P2 and P2 'that form an angle θ
In each direction, the lenses 6a, 6
b, photodiodes 7a and 7b are arranged. An eye refraction value measurement system 8 is provided on the optical axis P3 in the direction reflected by the dichroic mirror 5, and the eye refraction value measurement system 8 has a controller 9 and a target 2 in the AB direction along the optical axis P1. Stepping motor 10 for driving, three push buttons 11a, 11
An optotype setting unit 11 having b and 11c and a television monitor 12 are connected. Here, the dichroic mirror 5 transmits a visible light beam emitted from the light source 1 for alignment, and an infrared light beam emitted from a light source (not shown) inside the eye refraction value measuring system 8 for eye refraction value measurement. Has a light division characteristic of reflecting light. Further, the photodiodes 7a and 7b are provided so as to be conjugate with the cornea Ec when the eye E to be examined looks straight at the optotype 2.

A light beam emitted from the light source 1 for alignment passes through the target 2, the lens 3, and the lens 4 on the optical axis P1, passes through the dichroic mirror 5, reaches the cornea Ec of the eye E to be examined, and is emitted by the cornea Ec. Reflected light beam travels on the optical axes P2 and P2 ', and the lens 6a,
The light is projected onto the photodiodes 7a and 7b via 6b. If the amount of light received by the photodiodes 7a and 7b is continuously detected and becomes equal to or larger than a preset threshold value, the cornea Ec becomes conjugate with the photodiodes 7a and 7b, and it can be detected that the cornea Ec has viewed the target 2 from the front.

At the time of measurement, an eye refraction value measurement system 8 is used to measure the eye refraction value.
Is emitted from the lens, reflected by the dichroic mirror 5 and reaches the fundus Er. The reflected light flux returns to the eye refraction value measurement system 8 via the same optical path, and is received inside the eye refraction value measurement system 8, An eye refraction value is calculated from the position of the fundus reflection image.

When the examiner presses the push button 11a or the push button 11b on the target setting section 11, the stepping motor 10
Can be driven to move the target 2 in the A direction or the B direction one step at a time. Also, on the TV monitor 12,
An anterior segment image M, which is taken at any time by a television camera (not shown) inside the eye refraction value measuring system 8, and the calculated eye refraction value H1 are displayed.
Is displayed.

When measuring the eye refraction value, the examiner adjusts the position of the eye E while observing the anterior eye image M on the television monitor 12, and then controls the stepping motor 10 by the controller 9.
To automatically move the target 2 in the AB direction. Alternatively, by pressing the push buttons 11a and 11b on the optotype setting unit 11, the optotype 2 is moved stepwise by the examiner's intention, and the eye refraction value measurement system 8 measures the eye refraction value each time. I do. Then, if necessary, it is possible to detect from the corneal reflected light obtained by the photodiodes 7a and 7b whether or not the position of the eye E is strictly adjusted.

When the eye E can fixate on the target 2,
The examiner adjusts the position of the subject's eye E while observing the anterior segment image M on the television monitor 12, and guides the diopter while automatically moving the optotype 2 by the controller 9 to measure the eye refraction value. The system 8 measures the eye refraction value.

For example, when the concentration is lacking as in infants and the like, or in the case of a nystagmus patient, it is not possible to predict when the subject's eye E moves.
If the target 2 cannot be fixed while the diopter is being guided, the position of the target 2 is measured in advance, and the eye refraction value is measured without guiding the diopter. That is, the photodiode 7a,
As soon as the eye E detects that the eye 2 has seen the eye 2 as the normal eye using the corneal reflection light on the surface 7b, the eye refraction value measurement system 8 automatically starts measuring the eye refraction value. Although diopter guidance requires time, the measurement of the eye refraction value is instantaneously completed, so that even if the eye E is moved during the measurement, the measurement does not become impossible.

Note that, even in the case of measuring the eye refraction value of a subject other than an infant, a nystagmus patient, or the like, the measurement may, of course, be performed using the positioning means using the corneal reflected light on the photodiodes 7a and 7b. Further, when the push button 11c is pressed, the eye refraction value H1 and the diopter H2 of the target are displayed on the television monitor 12, and the examiner judges from both of them and sets the position of the target 2 if necessary. Correct and perform the measurement again.

[Effects of the Invention] As described above, the eye refractometer according to the present invention can accurately measure refraction by inducing diopter, and can fix the optotype and quickly perform refraction measurement on an easily mobile eye. it can.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an embodiment of an eye refractometer according to the present invention. Reference numeral 1 denotes a light source, 2 denotes a target, 7 denotes a photodiode, 8 denotes an eye refraction value measurement system, 10 denotes a stepping motor, 11 denotes a target setting unit, and 12 denotes a television monitor.

Claims (3)

(57) [Claims] 1. An optotype means for moving an optotype system member in the direction of the optical axis to change diopter diopter and to guide diopter, and projecting a light beam onto a fundus of an eye to be examined and photoelectrically detecting reflected light thereof. Eye having a refractive power measuring means for obtaining an eye refraction value, and selecting means capable of allowing an examiner to select how to move the optotype system member at the time of measuring the refractive power by the refractive power measuring means. Refractometer. 2. The method according to claim 1, wherein a refraction measurement is performed by guiding the target while moving the target, and a refraction measurement is performed by fixing the target system member to a set diopter. Item 1
An eye refractometer according to item 1. 3. The eye refractometer according to claim 2, wherein the refraction is measured by manually setting and fixing the visual target diopter.