Abstract: measure according to 3 times of the basic length of the following measuring line, cover one side of your eyes and slowly look at the dot in the middle. (if the basic length of the measuring line is 10cm, the distance of about 30cm can be tested). Visual acuity test method: measure according to 20 times the basic length of the following measuring line, covering one eye. (if the basic length of the measuring line is 5cm, it can be tested at a distance of about 1m). Astigmatism test method: cover one eye and look at the following lines with the other eye. Is there any line particularly clear? Retina test method: measure according to 3 times the basic length of the following measuring line, cover one eye and slowly look at the center dot 。 (if the basic length of the measuring line is 10cm, it can be tested at a distance of about 30cm). If the surrounding line is skewed or unclear, the retina may be abnormal. Color vision test,
vision test
method: measure according to 20 times the basic length of the measuring line below and cover one eye. (if the basic length of the measuring line is 5cm, it can be tested at a distance of about 1m)
astigmatism test
method: cover one eye and look at the following lines with the other eye. Is there any line particularly clear?
retinal test
Methods: measure according to 3 times of the basic length of the following measuring line, cover one side of the eye and slowly look at the dot in the middle. (if the basic length of the measuring line is 10cm, it can be tested at a distance of about 30cm). If the line around
and
is skewed or unclear, the retina may be abnormal.
and
color vision test
and
are shown in the following color blindness detection charts. If the numbers seen are different from the lower numbers, there may be color vision abnormalities.
1. 0.003% of the total color blind
and
population are extremely rare. They can only distinguish black and white because they are completely unable to recognize the color.
2. Red and green color blindness
people with abnormal color blindness who cannot be recognized by red and green.
in case of red color blindness, red will be regarded as a darker brown; In the case of green color blindness, green will be regarded as yellow.
3. Orange color blindness
are rare color blindness, and blue and yellow can not be felt at all.
4. The color of
with weak color will not be recognized if it is a long-distance color or the color degree is relatively low.
and
do not have enough ability to distinguish colors in a short time. In the case of strong contrast, for example, loess color and yellow, when
and
are adjacent to red, they will be regarded as yellow, or when they are adjacent to yellow, they will be regarded as red.
5. Night blindness
at night or in a dark place, the color will disappear, and what you feel is no color.
and
are first red, then vermilion yellow, yellow, green, blue, etc., losing the sense of color in sequence.
and
return to the place with light or light again, and the first thing to restore is blue.