Color Blindness

Color blindness is a genetic condition. All color-blind people can see almost all colors but they cannot distinguish between certain colors. Not all of them have trouble with the same colors. Most cannot distinguish between red and green. Some cannot distinguish between blue and yellow. A very small group see only black and white (monochromatism).  They are not able to see shades or tones of the same color. It mostly affects men than women.

What is Color Blindness?

Color blindness, which is 20 times more common in men than in women, is one of the most common hereditary disorders. A vision defect characterized by the inability to see colors correctly due to the absence or malfunction of some nerve cells in the eyes, namely cones, is called color blindness. Individuals with color blindness do not see the difference between certain colors or shades or may have difficulty perceiving the brightness of colors.

Some conditions that negatively affect eye health can lead to the development of different vision defects, and vision defects can negatively affect the quality of life of individuals. Color blindness is a vision defect in which colors are not seen as they are and is caused by the improper functioning of cones, a type of nerve cell in the eye retina.

Cones are nerve cells that perceive colors in the light spectrum that includes all wavelengths that humans can see. There are three types of cones in healthy individuals. Cones that perceive red, namely L cones, perceive long wavelengths of approximately 560 nanometers. The green-perceiving cones, or M cones, perceive medium wavelengths. The blue-perceiving cones, known as S cones, have the ability to perceive short wavelengths.

Different types of color blindness may occur depending on the working condition of the cones in the eye:

• Rod monochromacy (Achromatopsia) occurs when all or most of the cones are missing or do not work properly. In addition to seeing all names in gray and their shades, different vision problems that may affect quality of life may also occur.
• Blue cone monochromaty is rarely seen. In this vision defect, where the S cones are active while the L and M cones may not be active, difficulty distinguishing between colors may be experienced, and other eye problems such as nystagmus, light sensitivity and myopia may be experienced as a result of objects mostly being seen in gray.
• Blue-yellow color vision defects are less common than red-green color deficiency. Tritanopia causes the blue light to not be perceived correctly as a result of problems in the S cone.
• Red, pink, light blue and violet colors can usually be seen. In the case of tritanomaly, all three types of cones are formed, but the sensitivity of the S cones to blue light is less than it should be. Accordingly, the color blue can be seen as green, while the color yellow can be seen very little or not at all.
• Red-green color deficiency is the most common type of color blindness. It can cause colors or areas that contain a little red and green to be seen as different colors.
• Protanopia is characterized by the inability to perceive red light correctly due to the lack of L cones, and colors are mostly seen as blue or gold tones. Deuteranopia, in the case of the lack of M cones, prevents the correct perception of green light. Some shades of red can be confused with green tones, and bright shades of yellow and green cannot be distinguished. Protanomaly is a condition in which all three types of cones are present, but the L cones are less sensitive to red light than they should be. In this case, the color red can be seen as dark gray. In the case of deuteranomaly, individuals are sensitive to all three types of cones.

What Causes Color Blindness?

Hereditary color blindness can be caused by mutations in genes. Blue-yellow color deficiency usually develops later. Non-congenital color vision defects can occur due to different environmental reasons. Some of the conditions that cause color blindness can be listed as follows:

Genetic factors
Exposure to chemicals such as heavy metals that damage the nervous system
Use of certain medications, including hydroxychloroquine for the treatment of rheumatoid arthritis
Presence of eye diseases such as macular degeneration, glaucoma and cataracts that develop due to aging
Various medical conditions that affect the brain or nervous system, including Alzheimer’s disease, diabetes and MS
Exposure to welding rays for a long time
Retinal detachment
Laser-induced eye injuries
Certain brain tumors, especially those that affect the optic nerve or press on the brain
Radiation treatments

How to Understand Color Blindness?

The most obvious symptom of color blindness is the difficulty in distinguishing between colors that are not intense. In some cases, color blindness may be suspected because all tones are close to gray. However, a person can learn colors over time and if they have difficulty distinguishing colors, they may notice this at an older age. Since a person may encounter periodic effects while evaluating themselves, they may have difficulty reaching a definitive judgment. Therefore, the clearest result can be obtained with color blindness tests and examinations performed by a specialist and experienced doctor in the field. Although there are no symptoms at an early age, it is also possible for color blindness that comes from hereditary transmission or is acquired later to be a symptom of different diseases.

Having a color blindness test is an effective method for diagnosis and provides almost definitive results. The Ishihara test, Farnsworth test, Munsell D-15 test are the most commonly applied color blindness tests and are frequently used for diagnosis.

The color blindness test should be applied in a well-lit environment. Patients are asked to interpret the numbers and shapes they see on the test. If a deficiency in colors is detected, the doctor may request more detailed screening tests.

How is Color Blindness Treated?

Color blindness cannot be treated with standard drug treatments or surgical intervention. The reason for this is that color blindness is not a disorder but rather a deficiency and dysfunction.

The most effective method for treating color blindness, which is a hereditary disorder, is to use contact lenses specially produced for color blindness. Specially designed contact lens types, designed to eliminate the problem of people with color blindness, take on the task of changing the wavelength by regulating the eye and light relationship with their filters. In this way, it is possible to perceive colors clearly.

Color blindness is not a disease that can heal on its own. For this reason, it is absolutely necessary to be guided and followed by a specialist doctor.

Color Blindness Symptoms

The most obvious symptom of color blindness is that the individual has problems perceiving some colors in the images they encounter in daily life. A person with color blindness may have difficulty distinguishing traffic lights, may see some color tones as the same color, and may perceive colors more dullly than normal. Since children who are in the learning and naming period of colors can learn certain colors as the same color, it is possible for color blindness to go unnoticed for a long time.

In addition, especially in cases of color blindness that develop later, depending on the underlying disease, it is possible to see additional symptoms such as double vision, various levels of vision loss, eye pain, blurred vision and eye redness.

The most common symptoms of color blindness can be listed as follows:

Inability to distinguish between the colors red, yellow, orange, green and brown
Colors appear duller than normal
Difficulty distinguishing shades of purple
Confusion of red and black