• What Are the Symptoms and Causes of Color Blindness?

    Written By:
    Reviewed By: Odalys Mendoza MD
    Sep. 06, 2019

    The symptoms of color blindness can range from mild to severe. Many people have such mild symptoms that they are unaware that they have a color deficiency. Parents may only notice a problem with a child when he is learning his colors.

    The symptoms include:

    • trouble seeing colors and the brightness of colors in the usual way;
    • inability to tell the difference between shades of the same or similar colors. This happens most with red and green, or blue and yellow.

    Except in the most severe form, color blindness does not affect the sharpness of vision. The inability to see any color at all and to see everything only in shades of gray is called achromatopsia. This rare condition is often associated with:

    Causes of color blindness

    Most people with color blindness are born with it. This is called a congenital condition. Congenital color vision defects usually pass from mother to son.

    These defects are due to partial or complete lack of cones in the retina. Cones help you to distinguish the colors red, green, and blue.

    Most color vision problems that occur later in life are a result of:

    • disease
    • trauma
    • toxic effects from drugs
    • metabolic disease, or
    • vascular disease

    Color vision defects from disease are less understood than congenital color vision problems. Disease-specific color blindness often affects both eyes differently. Color vision defect caused by disease usually gets worse over time. Acquired color vision loss can be the result of damage to the retina or optic nerve.

    Who is at risk for color blindness?

    Men are at much higher risk for being born with color blindness than women, who seldom have the problem. An estimated one in ten males has some form of color deficiency. Color blindness is more common among men of Northern European descent.

    Having certain conditions may increase your risk for acquired color deficiency, including:

    Certain drugs may also increase your risk for acquiring color blindness. The drug hydroxychloroquine (Plaquenil) can cause color blindness. It is used to treat rheumatoid arthritis, among other conditions.