Color blindness can have major consequences for daily life. You no longer recognize a basic color, which makes the entire world around you look different. Sometimes it happens that only shades of white, gray and black are seen. What causes it and can something be done about it?

Color blindness

• Altered spectrum
• Human trichromatic vision
• Cause of color blindness
• Changing with time
• Is there a treatment?

Altered spectrum

If there is color blindness, this means that the person often cannot recognize a specific color. These are the three basic colors blue, green and red. All other colors can be composed with those colors. Often a basic color is not recognized, causing it to be filtered out of the spectrum of the viewing person. This means there is a different color perception of the world. It is also very exceptional that a person no longer sees color at all. An example of a very famous celebrity who also suffered from color blindness was the painter Vincent van Gogh.

Human trichromatic vision

The retina of the eye is covered with cones and rods. The rods are ideal for seeing in the dark. To recognize color during the day or when there is sufficient lighting, the cones on the retina are used. In principle, every person has three types of eye cones, with which the three different main colors can be recognized separately. This is done using photoreceptors, which are active at three different wavelengths. Every intermediate color is made up of these three basic color wavelengths and so the composition of a specific color at a slightly different wavelength can also be recognized. This is the principle of trichromatic vision. With properly functioning eye cones we can recognize all colors through the emitted wavelengths.

Cause of color blindness

The present explanation of human trichromatic vision explains why people cannot see a certain color if there is something wrong with a cone type. Color blindness occurs if:

• one of the three cone types is not functioning properly;
• one of the three cone types is not present;
• one of the three cone types is damaged.

These abnormalities can be present from birth and are therefore genetically determined. Because one cone type does not work, a basic color is lost, so that the color perception is composed with the two remaining color wavelengths. Something that originally has the color purple appears red when the color blue is no longer recognized. It may also be that no color is recognized. This type of color blindness will not change over time.

Changing with time

In addition to the aforementioned unchangeable color blindness, there is also color blindness, which one gradually acquires (acquired color blindness). The cause could then be due to:

• the aging of the body;
• having eye problems such as: green cataracts, common cataracts, reduced wavelength perception due to a deteriorated yellow spot (this is the central point in the eye where the sharpest details are usually perceived) or changes in the blood vessels in the eyes due to untreated diabetes ;
• an injury to the eye and side effects of medications;
• brain tumor that compresses the brain.

Is there a treatment?

Depending on the cause of color blindness, it may or may not be treated. Successfully removing a brain tumor can mean that color recognition is restored. Cataracts can also be corrected with a simple procedure, which restores the original sharpness and color recognition. An indirect way is to put in colored contact lenses, so that specific colors are better recognized. People with color blindness are often taught to recognize color indirectly. Someone must then indicate what color an object actually has and that is compared with the recognized color. In this way, it can be learned in an indirect way how to deal with color blindness.

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