Color blindness: What is it, what are its causes and how is its treatment?

When there is a problem with the perception of colors through vision in a person, it could be a sign of color blindness. Although some cases of this disease have to do with other problems that affect vision. Therefore, today we will talk about what is color blindness, what are its causes and how is its treatment.

What is color blindness all about?

As mentioned at the beginning, color blindness has to do with the difference that exists when perceiving colors. Due to this, this disease is not related to blindness problems. So, when suffering from color blindness, the patient has trouble differentiating certain colors, such as between yellow and blue, or between green and red.

Visual impairment in color perception, simply called color blindness, is a hereditary disease that commonly affects men. And although women can also suffer from color blindness, it is not as common as in the case of men. Some medical organizations have determined that 8% of men are affected by color blindness. While in women this is a percentage of 1%.

One of the most common ways in which color blindness develops is the difficulty in perceiving the colors green and red. Less frequently, patients develop features that prevent them from identifying yellow and blue. Relative deficiencies between yellow and blue generally affect both men and women equally.

Color blindness is rather the existence of an abnormality in some of the cells that are responsible for being the photoreceptors in the eyes. Which are called cones and rods. They work in combination, and are connected to the brain centers through the optic nerve. If any of these cells are defective, an image with the required pigments will not be produced. Thus causing the development of color blindness.

What are the causes of color blindness?

When there are certain inconsistencies in the color receptor cells, color blindness develops, and this problem occurs inside the retina. Where there is no proper response to light waves, allowing a person to perceive a variety of colors.

There is an approximate 100 million rods within the retina of the human being, which have a greater sensitivity to light, but do not perceive color. In contrast, there are up to 7 million cones that are inside the eyes, and these are the cells that perceive the color of things. Found in the center of the retina, and are called the macula.

This macula has a central part known as the fovea, and it is the one that contains a large concentration of cone cells within the retina.

Between the causes of color blindness more important is genetic inheritance. Related to the deficiencies that exist in certain cone cells, or the absence of these. However, apart from the genetic makeup, there are also other causes of this disease:

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Although it seems a bit strange, one of the causes of color blindness is the intake of certain medications. Since, there are some that generate distortions in the perception of colors through vision. Certain antipsychotics, such as thioridazine and chlorpromazine, may cause color blindness.

Similarly, antibiotics such as ethambutol, used as a treatment for tuberculosis, can cause alterations in color vision. Adverse effects such as these should be considered by the specialist, before prescribing said drug.

Medicines for epilepsy such as tiagabine, are capable of reducing color vision by up to 41%. However, some specialists claim that these effects do not occur permanently.


Another of the causes of color blindness The most common is the presence of cataracts. Diseases like this discolor the perception of colors, causing them to appear less bright.

Having Parkinson's disease can lead to color blindness. It is a neurological disorder, which also affects color receptor cells. Causing damage to them, leaving them unable to function properly.

Likewise, suffering from kallma syndrome could cause the appearance of color blindness. This condition causes failure of the pituitary gland. Leading patients to unusual development in the genre. Where color blindness could be part of the symptoms that manifest in the disorder.

Other causes of color blindness

The appearance of color blindness could also be related to the signs of aging, since there is damage to the cells that are within the retina. Injuries or damage to the brain, especially in areas that have to do with vision, are another of the causes of color blindness.

On the other hand, prolonged exposure to highly toxic chemicals, such as styrene, could cause this disease. Since, it is related by losing the ability to distinguish colors.

Symptoms or consequences of color blindness

The consequences of color blindness or the characteristic symptoms of this disease have to do exclusively with the way in which colors are perceived. Contrary to what some think, it is uncommon for a patient with color blindness to observe only gray scales.

Most of the people who have been diagnosed with color blindness observe the colors, but some of them are discolored or confused with others. However, this has to do with the kind of visual impairment the person has.

If at any time an abnormality in the perception of colors is noticed, or it is different from what it was before, it will be necessary to contact a specialist. Losing color vision, or a defect in the retina, could be a sign of another health problem.

Types of color blindness

Taking into account the genetic origin, color blindness could be classified as acquired or as inherited. However, this disease is also classified, taking into account the ability to perceive certain colors.


This is one of the most serious cases of color blindness. Where people who suffer from it, can only observe in black and white, along with gray scales. It occurs because the patient does not have cones inside his retina, or he has significant neurological damage. Of all the types of color blindness, this is the rarest, with only 1 case developing in 100,000 people.


It is a class of color blindness that is between the moderate classification, and where one of the existing types of light is not perceived. And within this type there are three modalities:

Protanopia: There is a total absence in the photoreceptors that perceive the color red. Causing deficiencies in perception, with wavelengths that are too long. When looking at the color red, affected people perceive it as gray or cream.

Deuteranopia: The absent photoreceptors are those that are responsible for perceiving the green color, where the wavelength is medium, and it is the least serious form.

Tritanopia: Within the classifications of color blindness, this is the rarest type of all, and where there is a total absence of blue color receptors. So, the difficulty is presented for short wavelengths, and yellow is perceived as if it were pink.


Also called extreme or total color blindness, vision is also black and white, with certain shades of gray. A case like this if it has cones inside the retina, but two of the pigments that need to be in these cells are absent. The number of affected with this disease is very little.

Anomalous trichromy

Those who are affected by this kind of color blindness have defective cones in the retina, causing confusion in colors. This being the most common color blind classification and also has several modalities:

Protanomaly: trouble differentiating the color red.

Deuteranomaly: difficulties in the perception of the color green.

Tritanomaly: abnormality for blue color observation.

Treatment of color blindness

Currently no color blindness treatment in case of being hereditary. However, there are some strategies that help the patient to have a better orientation of the colors. For the most part, patients with color blindness adapt well to deficiencies in observing certain colors.

There are also glasses with color filters, or special contact lenses for patients with this disease. However, these are not a cure for color blindness, rather they help to identify colors much better and improve color vision.

Memory techniques in the order of the colors of the traffic lights, or marking objects with the color that is not perceived, is also another way to cope with the disease.


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