How to Identify Color Blindness

If you want to know whether you are color blind or not, the method is relatively simple. You can use pseudo-isochromatic pictures to identify and distinguish. You can also do color beam tests, or you can use mixed color mixing meters to measure. These are all common methods. By using these methods, you can know whether you are color blind or not. These are also some of the most common methods for diagnosing color blindness in medical treatment.

How to Identify Color Blindness

Color blindness and color weakness are mostly checked using subjective perception, usually under brighter natural light. Commonly used inspection methods are as follows.

1. False Same Color Picture

It is usually called a color blindness book, which uses dots of the same shade of hue but different colors to form numbers or graphics. People with color vision impairment have difficulty in identifying them and may make mistakes or be unable to read them. They can confirm what kind of color vision abnormality they have according to the color blindness table.

2. Color harness test

The method is to mix wool bundles of different colors and shades together and ask the subject to pick out the bundle of wool that has the same color as the standard bundle. This method is time-consuming and can only provide rough qualitative rather than quantitative results, making it unsuitable for large-scale screening inspections.

3. Color mixing tester

It can quantitatively record the amount of red and green light required to match in order to determine red-green color vision abnormality. This method is both qualitative and quantitative.

Clinical manifestations of color blindness

Color blindness is divided into total color blindness and partial color blindness, and partial color blindness includes red color blindness, green color blindness, blue-yellow color blindness, etc. Color weakness includes total color weakness and partial color weakness, and partial color weakness includes red color weakness, green color weakness, blue-yellow color weakness, etc.

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

This type of color blindness is also called third color blindness. Patients usually confuse blue and yellow colors. This symptom is relatively 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.

The color vision disorder is lower than that of achromatopsia, and there is no abnormality in vision or other complications of achromatopsia.

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.