JPH0310961Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) This invention relates to a visual acuity testing device, and more specifically, it is a visual acuity testing device for a subjective testing method that utilizes the characteristic reactions related to figure recognition in infants. In particular, it relates to the improvement of products used for infants and toddlers around the age of two.

(Prior art) Human eyesight significantly develops during the first few years of life, that is, during infancy. Therefore, it is necessary to detect abnormalities in vision in infants early and to actively manage vision development. The basis is to inspect the

Conventional visual acuity testing methods are broadly divided into electrophysiological testing methods, psychophysical testing methods, and subjective testing methods.
Some subjective testing methods utilize direction discrimination and form discrimination.

Among these, the Landolt ring, hiragana, katakana, or alphabetic indexes are the most commonly and fundamentally used methods based on direction identification methods. However, testing methods using these methods are not necessarily a pure reflection of visual perception, as the ability to interpret text is greatly influenced by the resulting ability to express the results, and they are not suitable for testing infants (or those with intellectual retardation). cannot be said to be sufficient.

For this reason, so-called picture visual acuity charts have been proposed as an alternative to these visual markers. However, in this case, the correlation between the shape and size of the picture and the size of Randall's ring is not clear, so there is a drawback that it lacks accuracy as a visual acuity testing method. In addition, since the principle is based on the judgment of pictures, it is inevitable that it will be greatly influenced by the life experience and level of intellectual development of the infants who are the subjects, and it is difficult to compare objective visual acuity. Not suitable. There are also restrictions on the age at which people will respond to the test.

A testing method that utilizes infants' instinctive visual reactions is PL (Preferential
There is something called the looking) method. However, this method is expensive in terms of equipment, and it is not a desirable method because infants instinctively show negative reactions to devices. In addition, there is the disadvantage that as the test subject's intelligence develops, his or her instinctive reactions become weaker.

In addition, the dot test has been proposed as a subjective testing method for infants. This involves shining light from behind onto a transparent plate with dots of various sizes drawn on it.
An opaque hole-perforated mask is placed on the front, and the position of the mask is shifted appropriately, and the infant is asked to point out the dots visible inside the holes with his/her finger. This method is relatively accurate and has some effectiveness. However, it still has the drawbacks of requiring special equipment, and moreover, infants often do not show interest in simple dot patterns, making it difficult to perform the examination smoothly.

(Summary of the invention) The purpose of this invention is to skillfully utilize the interest and interests of infants and young children without being influenced by the level of intellectual development or life experiences of subjects aged around 2 years old, and without the need for special equipment. The aim is to accurately perform the visual acuity test.

Therefore, in this invention, a plurality of cards displaying the same specific figure are used, and a card in which at least one dot of a different size is displayed on each card within the figure; The gist of the test is to sequentially present cards without dots to the examinee and ask them to answer whether there is a dot or not.

(Embodiment) FIGS. 1A to 1C show an embodiment of the testing device of this invention, in which a human face is used as a specific figure, and dots are used as eyes in the face. It is.

On the card shown in Figure 1A, two dots with a diameter of 0.9 mm are displayed at the eye positions on the face. The dimensions of the dots on the card shown in Figure 1B are as shown in Figure 1A.
It's twice as much as it is on the card. Figure 1C
The card shown here does not have a dot on the face where the eyes should be placed.

What is shown in FIGS. 2A and 2B is a part of the second embodiment of the testing tool of this invention, in which a rabbit's face is used as a specific figure.

In either case, numbers such as 1/2, 1, 2, etc. are written on these cards depending on the size of the dot, and when a test is performed as described below, visual acuity is determined based on these numbers. It is decided.

Incidentally, the dimensions of the dots, the number of cards, etc. in this invention are not necessarily limited to those shown in the drawings, but may be appropriately selected in consideration of the characteristics of the population of subjects to be examined.

Although various figures can be used, it is preferable to use a human face because the starting point for infants' primitive vision is the mother's face, which is within reach. Furthermore, since infants and young children generally show an interest in small animals such as rabbits, it has been confirmed that it is advantageous to use the faces of small animals such as rabbits.

Next, an example of how to use the visual acuity testing device of this invention will be explained. The examiner sits face-to-face with the infant test subject.
The test is carried out in a daily atmosphere under natural or indoor lighting between 500 and 1000 lux. Also, cover one eye of the subject with an eye patch.

The card is placed in the palm of the hand like a playing card and presented to the test subject at a position approximately 30 cm in front of the test subject. There is no particular order in which the cards are shown, but it is easier to understand if the card with the largest dot is shown first. While presenting the card in this way, ask the child, for example, ``I have an eye for you,'' and have them answer ``Yes'' or ``No.'' Then, ``Your eyes gradually became smaller,
As you move along, say something like, ``There's something as small as trash.'' If the child answers ``Yes,'' ask ``Where'' to confirm and have them point to it.

Here, the cards without dots (0 cards) are used to confirm the reliability of the answers, and are interposed here and there to check the test subject's reaction.

Repeat this process 2 to 3 times and use the lowest card value as the test value. This value is calculated from the reciprocal of the visual angle and is called, for example, dot visual acuity. It is best to spend 2 to 3 seconds on each card and complete the inspection in 2 to 3 minutes in total.

As described above, according to this invention, since the test optotype is a dot, it is easy to compare with the Landolt ring, and since no equipment is used, it is simple and inexpensive, and does not cause negative reactions in infants. This makes it possible to conduct inspections while attracting the interest of people.

Furthermore, it has been confirmed that the obtained test values have a significant correlation with the test values obtained using the standard Landolt ring, so the test results can be universally quantified.

Furthermore, when the standard Landolt ring test method for testing distance visual acuity is combined with the test method of this invention for testing near visual acuity, it can become an effective means for detecting farsightedness and amblyopia.

[Brief explanation of drawings]

Figures 1A to 1C show the first embodiment of this invention,
Moreover, FIGS. 2A and 2B are plan views showing the second embodiment, respectively.

Claims (1)

[Scope of Claim for Utility Model Registration] [1] Consists of at least two cards displaying the same specific figure, and at least one dot of a different size for each card is displayed within the figure. A visual acuity test device comprising at least one card and at least one card in which no dot is displayed within the figure. [2] The test tool according to claim 1, wherein the specific figure is a face of a living creature.