How to test for color blindness?

We all know that if you are color blind, you cannot get a driver's license, and in the world of color blindness, there is only one color. In fact, some people are not color blind, they just have some blind spots when seeing colors. If you want to test whether you are color blind, you should understand the symptoms of color blindness.

1. Achromatopsia

It is a complete cone cell dysfunction, which is the opposite of night blindness (rod cell dysfunction). Patients prefer darkness and are afraid of light, which manifests as day blindness. There is only a difference in light and dark, but no difference in color, and the red appears dark and the blue appears bright. In addition, there are symptoms such as poor vision, amblyopia, central scotoma, and pendulum nystagmus. It is the most severe form of color vision deficiency and is less common.

2. Red-color blindness

Also known as the first color blindness. The patient is mainly unable to distinguish the color red, and cannot distinguish red from dark green, blue from purple-red, and purple. Green is often seen as yellow, purple is seen as blue, and green and blue are mixed as white.

3. Deuteranopia

Also known as second color blindness, patients cannot distinguish between light green and dark red, purple and cyan, purple and gray, and perceive green as gray or dark black. In clinical practice, red-green color blindness and green-color blindness are collectively referred to as red-green color blindness, which is more common. The color blindness we usually talk about usually refers to red and green color blindness.

4. Blue-yellow color blindness

Also known as third color blindness. The patient confuses blue and yellow colors, but can distinguish red and green, which is rare.

5. Panchromatosis

Also known as red, green, blue and yellow weak. The color vision impairment is lower than total color blindness, and there is no abnormality in vision or other complications of total color blindness. It is possible to distinguish objects when their colors are dark and bright; if the colors are light and unsaturated, it is difficult to distinguish and is rare.

6. Partial color blindness

There are red-green color weakness (first color weakness), green-green color weakness (second color weakness) and blue-yellow color weakness (third color weakness), among which red-green color weakness is more common. Patients have poor sensitivity to red and green. When the lighting is poor, their color discrimination ability is close to red-green color blindness; but when the color of the material is dark and bright and the lighting is good, their color discrimination ability is close to normal.