chromosomeColor blindness is an eye condition that affects how the patient sees color. Pigments that detect color variations do not work properly causing difficultly differentiating between certain colors or shades of the same color.

Who is at Risk?
Color blindness is an X-linked trait. This means men are more commonly affected than women. Few women suffer from color blindness  because the Y chromosome cannot protect male children against the faulty X chromosome gene that causes color blindness.

Color blindness can also be caused by hydroxychloroquine, a medication prescribed for the treatment of arthritis, lupus and malaria. Brand names for hydroxychloroquine include Plaquenil and Quineprox.

colorblindness the american flag Types of color blindness

There are 8 different types of color blindness

  1. Protanopia
  2. Deuteranopia
  3. Protanomaly
  4. Deuteranomaly
  5. Tritanopia
  6. Tritanomaly
  7. Rod monochromatism
  8. Cone monochromatism

Hereditary Color Deficiency

  • 8-10% of males and 1/200 females (0.5%) are born with red or green color deficiency.
  • Sex-linked recessive condition (X chromosome).
  • Protanomaly—red cone peak shifted toward green (1%)
  • Protan Dichromat—red cones absent (1%)
  • Deuteranomaly—green cone peak shifted toward red (5%)
  • Deutan Dichromat—green cones absent (1%)
  • Hereditary tritan defects are rare (0.008%)
Color Deficiency Females Males
1 in 10,000 1 in 100
1 in 10,000 1 in 100
Protanomaly 1 in 10,000 1 in 100
Deuteranomaly 1 in 250 1 in 20
Tritanopia 1 in 12,500 1 in 12,500
Tritanomaly  Rare  Rare
Rod monochromatism
 Rare  Rare
Cone monochromatism  Rare  Rare


The most common form of color blindness makes distinguishing greens from reds nearly impossible or impossible. A less common form of the condition affects how the eye sees yellows and blues. Patients with the less common form of color blindness may also have trouble seeing greens and reds. Achromatopsia, the rarest form of color blindness, renders the patient unable to see any color. Achromatopsia is also associated with jerky eye movements, lazy eye and light sensitivity. Patients often have poor vision.


Mild forms of color blindness may go undetected for life. Parents typically notice color blindness in early childhood when children are learning colors. Doctors use cards with pictures represented with different colors to diagnose the condition. Patients are asked to verbalize the images on the cards. Certain images are invisible to patients with color blindness.


There is no treatment for color blindness. Patients with color blindness may be fitted with special contact lenses that make it easier to differentiate between colors. The contact lenses make it easier for color blind adults to live and work normally in careers that require accurate color vision.

Color Blindness and Pregnancy
Color blindness is a genetic trait passed on children via an affected X chromosome. Color blindness does not cause pregnancy or fetal complications. The condition does not impair future fertility.

Life Expectancy
Though there is no cure for color blindness, advances in vision technology allow adults with the condition to lead normal lives. Contact lenses are available that allow color blind adults to see variations in color. These lenses make it possible for adults with chromatelopsia to hold jobs and careers that require seeing color like painters, electricians, cooks, teachers and many other professions.