SU37256A1 - Instrument for determining hemeralopia - Google Patents

Description

It is extremely important for professional selection, especially for the Red Army, to study night vision at the present time because of the lack of a simple, time-consuming method of testing. It is obvious that persons suffering from so-called "night blindness" cannot bear a number of official duties, for example, a pilot-to make night flights, a chauffeur-at dusk to drive a car, a Red Army man-guard at dusk or at night.

Recommended in the manuals on oftolmalogii instruments are not available for sale.

Naturally, finding a simple way to study night vision is an extremely important task both for outpatient practice in deciding the state of light sensation in persons complaining of so-called night blindness (hemeralopia) and for professional selection.

The proposed method is based on the Purkinje phenomenon, the essence of which is that with varying intensity of illumination, colors change their relative brightness. So, when dusk comes, there is a displacement of the place of greatest brightness from red-yellow colors to green-blue colors.

According to modern views, based on; of the Purkinje phenomenon lies in the fact that the retinal cones, mainly functioning in our lower vision, cease to function when the illumination is significantly weakened, giving way to the apparatus of retinal rods, which is more sensitive to weak stimuli and is most sensitive in time to the green rays, which in this case it seems the brightest.

In a person who is not oriented at a weak visual irritation, there is either a significant decrease in the functional ability of the rods, or the complete absence of such an ability. In this and in another case, such an anomaly of vision must say that the green-blue rays, when attenuating the light, will not seem to be relatively brighter for it than the yellow-orange rays.

For the study of night vision, the proposed device serves as a method based on the Purkinje phenomenon.

In the attached drawing of FIG. 1 shows a view of the proposed device from the side, partially in section; FIG. 2 is a side view of where the oculars are placed ;; FIG. 3 is a top view, also partially in section; FIG. 4-view color table for testing.

The proposed device consists of an etaplic-black painted quadrilateral box, on the upper side walls of which there are buttons 3 for fastening black matter, which serves to cover the head with the test. In the front wall of the device there are two cone-shaped oculars 4 and a cylindrical gaiter 5, into which a cover 9 is inserted, through which a shaft 12 held by a yoke 10, carrying a metal plate (cassette) for placing a colored table.

Outside on the rod / 2 there is an “indicator washer indicating the races: the composition of the colored sectors of the table: in a cassette //.

The color table (fig. 4) consists of two pairs of colored pieces of paper (greenish blue, orange, red and yellow). The colors of the paper correspond approximately to the colors of the ostavda 79 pa, 13 pa, 21 pa 41 08 pa.

In the side wall of the box there is a slot of 5 cm in length and a width of 2 mm in width, covered with 8 frosted glass held by the slider. The size of the slit can be changed by using the catch 23, moved by means of the screw 22 C installed in the couplings 25 With the indicator arrow for indicating on the scale of the slit opening. At the front end of the slot there is a bluff. .-housed light screen - flap 7 for more uniform illumination of the color table. An electric lamp with a car-cartridge 28 is installed outside the slot, it is covered by a half-cylinder with a special cap / 5. The electric bulb is powered by a 12 Bolt ak: cumul torus.

During the test, for the purpose of preliminary adaptation to light, the subject looks through the cone-shaped oculars (his head is covered to darken with black matter) at a matte plate located in the back wall of the device, in the place of a lid that is previously removed. A light source is placed 30 centimeters behind the matte plate) 50-watt electric bulb. After a 2-minute pre-adaptation to light, the lamp goes out and the matte plate is quickly replaced with a cover with a colored table.

The explorer, at a certain speed, uses the screw of the valve to expand the slit for accessing light from a 5-watt light bulb. The subject is asked to answer the question which papers are lighter on the table. Normally, the eye constantly finds that it is greener than orange and yellower than red. Red and yellow pieces of paper are listed in the table to eliminate the possibility of a simulation, because even for gemeralopa, yellow is always lighter than red. To eliminate the possibility of memorizing the location of the paper during mass testing, the color table is made rotating.

The subject matter of the invention.

A device for determining Förster’s type of hemeralopia, consisting of a dark box with two eyes and a side lighting slit, characterized in that for determining hemeralopia, inside the wall, opposite wall of the eyes, a rotatable handle 12 of the cassette //, The table is placed in quadrant colors in green-blue, orange, red and yellow.

to the author's testimony of S. V. Kravkov and N. A. Vishnevsky J 37256

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