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Tres mujeres

Farnsworth D-15

Color discrimination test 

Pintura de los colores

Dyschromatopsia commonly known as colour blindness  is a condition in which you cannot see colors normally.

In the retina, there are two types of cells that detect light. These cells are called rods and cones. Rods only detect light and dark and are very sensitive to low levels of light. The cones detect colors and are concentrated near the center of vision. There are three types of cones: some detect red, others green, and others blue. The brain uses the information sent by the cones to determine the color we perceive.

Dyschromatopsia or color blindness, can occur when one or more types of cones are absent, do not function, or detect a different color. 


There are different types and degrees of dyschromatopsia. Some people with mild color vision deficiencies detect colors normally in good light but have difficulty in dim light. Others cannot distinguish certain colors in any type of light. The most severe form of dyschromatopsia, in which everything appears in different shades of gray, is rare. The most common forms of dyschromatopsia usually affect both eyes equally and remain stable throughout life. You are usually born with this condition, but in some cases it can be acquired later in life. A change in the way you see colors may indicate the presence of a more serious problem. Anyone who notices a change in the way they perceive colors should consult an ophthalmologist.

Symptoms of dyschromatopsia:

The symptoms of color blindness can range from mild to severe. Many people have symptoms so mild that they do not realize they have color deficiency or do not see colors well. Sometimes parents notice a problem only when the child is learning colors.

Causes of dyschromatopsia:

Most people who have dyschromatopsia are born with this condition. These defects are due to a partial or total absence of the cones in the retina. Cones help distinguish red, green and blue colors.

Most color vision problems that appear later in life result from:

  • an illness

  • a trauma

  • the toxic effects of some medications

  • a metabolic disease 

  • a vascular disease


Loss of acquired color vision may result from damage to the retina or the optic nerve.

Who is at risk for having dyschromatopsia?

Certain diseases can increase the risk of acquired color deficiency, including:

  • glaucoma 

  • diabetes

  • macular degeneration

  • Alzheimer's disease

  • Parkinson's disease

  • chronic alcoholism

  • leukemia

  • sickle cell anemia

Certain medications can also increase your risk for color blindness. Hydroxychloroquine (Plaquenil) can cause color blindness. It is used to treat rheumatoid arthritis, among other conditions.


Diagnosis of dyschromatopsia: 

The ophthalmologist can perform a relatively simple test in the office to determine if you have any alterations in color discrimination, however, the Farnsworth D15 test is the quintessential test necessary to determine the specific type of alteration you are experiencing.

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