Color Blindness Definition, Reason, Symptoms, Treatment & Prevention

Color Blindness Definition, Reason, Symptoms, Treatment & Prevention


Color blindness is a condition when a person can still see colors, but is unable to distinguish between these colors. Color blindness is generally inherited from parents and is more common in males (5–8%).

The most common type of color blindness is red-green color blindness. In this case, red and green are seen as the same color, which is brown.

Color Blindness Symptom

Symptoms of color blindness can be mild or severe. Most sufferers experience mild symptoms, so they are not aware that they are color blind.

Parents usually suspect that a child has color blindness when it is difficult to distinguish colors that appear at traffic lights or have difficulty mentioning educational material related to colors.

Symptoms of color blindness that generally occur are:

  • It is difficult to distinguish the color and brightness of the color.
  • Difficulty distinguishing similar shades of colors, such as red from green or blue from yellow.

People who cannot distinguish colors at all, or all colors appear gray, are called achromatopsia.

This condition is very rare, and is usually associated with amblyopia (lazy eye), nystagmus (rapid and involuntary eye movements), sensitivity to light, and poor visual acuity.

Color Blindness Reason

The process of seeing the colors of different light spectrum is a complex matter. This process begins with the eye’s ability to distinguish three main colors, namely red, green and blue.

Light enters the eye through the cornea, passes through the lens and vitreous body, onto the cone cells in the retina.

Cone cells contain chemicals, which play a role in distinguishing colors. People with normal cone cells can distinguish colors easily.

Whereas those who lack chemical substances in the cone cells can only see two of the three main colors.

Most cases of color blindness are congenital (congenital), which are usually passed from mother to son. This disorder can be mild to severe, affects both eyes, and the severity does not change with age.

There are also color blindness that are acquired or caused by disorders of the retina or optic nerve due to injury, side effects of drugs, metabolic or vascular disorders. This type of color blindness usually occurs in only one eye, and tends to get worse over time.

The following are various risk factors that increase a person’s chance of experiencing color blindness:

  • Male gender. The chance of experiencing congenital color blindness is higher for men than for women, which is as much as 1 in 10 men.
  • Aging. The ability to see and distinguish colors will slowly decrease with age.
  • Disease. Some diseases that can reduce the ability to see color, namely coircell anemia, diabetes, macular degeneration, Alzheimer’s disease, glaucoma, Parkinson’s disease, alcoholism, and leukemia.
  • Drugs. Medications aimed at heart disease, high blood pressure, rheumatoid arthritis, erectile dysfunction, infections, neurological and psychological disorders can reduce the ability to see and distinguish colors.
  • Chemicals. The ability to see and distinguish colors can be lost due to exposure to chemicals, such as carbon disulfide and chemical fertilizers.


Color blindness can be checked through a simple test, called the Ishihara test. This test shows patterns formed by colored dots.

People who are not color blind can name the numbers or shapes between the dots. Whereas those who are color blind will have difficulty or even not see any patterns. If the test is positive, the doctor will order a more complex confirmation test.

Color Blindness Treatment

Can color blindness be treated? Congenital color blindness cannot be treated and usually does not cause significant disability. Contact lenses or glasses with special filters can help people with congenital color blindness distinguish similar colors.

However, the use of these aids still cannot completely correct the inability of the eye to see various colors.

The ability to distinguish colors in color blindness that is acquired due to certain diseases or drugs will improve if the cause is drugs.

When to see a doctor

Immediately visit a doctor if you experience vision problems that appear suddenly or get worse quickly, and affect your ability to distinguish colors.


There are no specific recommendations for preventing color blindness. However, you can get an Ishihara test, either at home or with a doctor, if there is a family history of color blindness, or you suspect you have color blindness.

Especially for children, eye examinations and color blind tests need to be done before entering school age.

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