The 3 types of color blindness

Not all color blind perceives colors the same, since the condition has several manifestations. We show you what they are and their characteristics.

Last update: December 29, 2021

Color blindness is an eye condition characterized by difficulty in perceiving wavelengths of color. Most cases develop from genetic causes, although it is also possible to manifest color blindness due to environmental interactions. Since there are several types of color blindness, it helps to be aware of them and their differences.

Indeed, this condition is not homogeneous in its manifestation. The National Eye Institute distinguishes three types of color blindness, and these in turn have several subtypes. Not every patient diagnosed with the condition perceives colors in the same way, something that must be taken into account to avoid prejudices and clichés. In the following lines we distinguish its variants and characteristics.

Main types of color blindness

In general, three types of color blindness are distinguished: the red-green, the blue-yellow and the complete or total. These categories are not specific, but have subcategories that describe the possibilities of manifestation within them.

Color blindness is caused by a defect in the cones of the retina (specialized cells) to collect or interpret the wavelengths of color. Either because they do not work or because there is an absence of any of them. We leave you with the types of color blindness so you can distinguish the differences between them.

Red-green color blindness

Color blindness can compromise those affected in various ways due to difficulty in performing daily activities.

Red-green color blindness is the manifestation of the most common condition throughout the world. According to studies, affects up to 8% of men of European descent, a percentage that drops to 0.4% in the case of women.

Those who suffer from this variant, have difficulties to distinguish the red and green tones due to the absence or the malfunction of the photoreceptors. These genes are encoded on the X chromosome, so this explains why it is more common in men. The following subtypes are distinguished:

  • Deuteranomaly: It is the most common type of red-green color blindness and affects people by making the color green take on a weaker hue, although they can still discriminate some shades. This means that with a lot of light green is perceived very close to red, and when it is scarce, it is close to black or brown (the dark tones of green). It is also known as Deutan color blindness.
  • Deuteranopia: people with this variant have trouble distinguishing the red, yellow, and green wavelengths of the spectrum. This is because they lack photoreceptors for the color green, or they don’t work at all. Therefore, they cannot discriminate this color in relation to those mentioned. The color spectrum is almost entirely assimilated in shades of yellow and blue.
  • Protanomaly: those who suffer from this variant have a mutation in the photoreceptor for the red wavelength, which means that it is interpreted in a weaker way. With a lot of light, red will approach shades of green, intense pink to gray and intense purple to blue, among others.
  • Protanopia: in this case, the patients lack the photoreceptors for the color red, which results in it being confused with green, yellow or gray depending on its tone and the absence or presence of light. For example, shades of violet, lavender, and purple are indistinguishable from blue, and traffic light red is perceived as off.

In general, we can say that deuteranomaly and protanomaly are the mildest forms of red-green color blindness.. Most of the people do not have complications in their day to day, many of them are even unaware that they are color blind. Deuteranopia and protanopia are the most serious variants and can create moderate complications in the perception of reality.

Blue-yellow color blindness

Blue-yellow color blindness is the second of the most common types of color blindness. It is also known as color blindness by Tritan, since the previous denomination can be misleading. Indeed, those who suffer from this variant have difficulty appreciating the blue color and blue-green tones.

They also have trouble distinguishing between yellow and red tones. Although it can be inherited, many people develop this type due to eye conditions or natural age-related degeneration. Two subtypes are distinguished:

  • Tritanomaly: People with this type have a defect in the photoreceptors of the blue pigment, which causes it to appear in pale or faint tones. It is a rare form of color blindness that affects men and women in equal proportions. People with this variant have trouble differentiating between blue and green, and red and purple.
  • Tritanopia: patients with this type lack blue wavelength photoreceptors, so they cannot distinguish this color at all. The subject will not be able to differentiate between blue-green, purple-red, and yellow-pink, among other combinations.

As in the previous types of color blindness, the difference lies in an anomaly of the cone to receive the wavelength (it is perceived with less brightness, duller or less intense) and the total absence of this or its operation (which prevents color appreciation regardless of its hue).

Complete or total color blindness

For the exact determination of the type of color blindness, it is important to consult with an ophthalmologist.

Complete or total color blindness describes the inability to distinguish the colors of the wavelength spectrum. It is not related to color agnosia, a condition in which the patient cannot perceive or interpret colors, although their eye is able to distinguish them physiologically.

It is the least common type of color blindness, since according to experts only 1 in 30,000 people manifest it. Like the previous case, it can develop with different degrees (mild, moderate or severe), but generally two subtypes are differentiated:

  • Baton Monochrome: often referred to as achromatopsia and is distinguished by the absence of cones on the retina. Aside from not being able to distinguish colors, people have trouble seeing in moderate and high light intensity contexts (their vision is better when there is less light).
  • Monochrome of cones: subjects with this variant have rods and cones. They also manifest sensitivity to light and reduced visual acuity, but this is less than in the previous case. According to gravity they can distinguish differences in brightness, but not in shades.

In general, a person with total color blindness perceives reality in different shades of gray. It is the most serious form of the condition, although fortunately the least frequent. It is often accompanied by vision problems that make it even more difficult to perceive objects and things.

With the latter we conclude the presentation of the types of color blindness. In its milder forms, especially the first two variants, many patients will be unaware that they have this condition. It is often a condition that is stable for life and affects both eyes equally. If you think you have a variant, do not hesitate to consult a specialist.

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