1. Pseudoisomorphic Graph Checking Method
Usually, Yu Ziping's and Ishihara's color-blind books are examined in bright natural light during the day. The distance between the examinee and the color-blind book is 75 ~ 100 cm. Ask the patient to read the numbers or figures in the color-blind book. Each recognized picture shall not exceed 10s, and the inspection results shall be recorded as described in the color-blind book.
2. Inspection method of colored wool
Put various designated colors of wool or paper in front of the subjects and let them choose similar colors, and then evaluate them.
3. Tone arrangement method
①FM- 100 color test: It consists of 93 hue sub, of which 8 are fixed reference sub and 85 are movable hue sub, and * * * is divided into 4 boxes. The inspection shall be carried out under natural light or standard illumination ≥ 2701x. Check the eyes separately and ask the subjects to arrange the tones in the order of color change. Record the serial number marked on the back of hue sub on the scoreboard, draw the axial diagram and calculate the total error score, so as to judge the type and severity of color vision abnormality.
The arrangement time of each box is generally 2 minutes or a little longer. The total error of normal people is below 1 13. Color blindness patients can reach more than 400 ~ 500 points. The nature of color blindness can be judged by axial analysis. ②D- 15 color wheel test: It is composed of 16 hue sub, one of which is a reference sub and 15 hue sub. The inspection method is basically the same as FM- 100 color test.
4. Color vision inspection method
The visual field seen from the observation hole of the color vision lens is divided into two parts, one part is yellow with a certain wavelength; The other part is a mixture of red and green. Only the brightness of yellow changes, and the mixing ratio of red and green is variable. Mix red and green to make it equal to the hue of yellow. According to the composition of red and green, it can be determined whether its color vision is normal or abnormal.
(1) Inspection method: ① When the examinee sits in front of the instrument and looks through the observation hole, he can see a disk with red or green upper part and yellow lower part. ② The inspector will adjust the monochrome knob on the right to the scale of 12.5, and instruct the inspector to rotate the color mixing knob on the left until the color and brightness of the upper and lower semicircles are exactly the same.
Write down the reading, and the normal equilibrium point is around 70 points. ③ The inspector turns the color mixing knob to 0 degree and instructs the client to turn the monochrome knob. Every time the mixing knob is increased by 10, the inspector will rotate the monochrome knob until it is equal, record its equal points, re-test it for three times and take its average value. ④ Record each result in a special table and draw an equilibrium curve.
(2) Results: ① Green and yellow are equal: congenital green is weak, congenital total color is weak, and acquired red and green color is weak. ② Equality of red and yellow: congenital weak red, congenital weak total color, rod-shaped color vision and acquired weak red and green. (3) those who are equal in green and yellow, red and yellow: congenital red blindness and green blindness, congenital panchromatic weakness and cone color blindness. ④ Those with yellow-green isochromatism and red-yellow isochromatism are not established: normal eyes, mild congenital red-green weakness, congenital and acquired total color weakness, acquired red-green weakness and amorphous rod color vision.