Table of ContentsView AllTable of ContentsHow the Eyes Perceive ColorSymptoms of Red-Green Color BlindnessCausesDiagnosisTreatmentCoping
Table of ContentsView All
View All
Table of Contents
How the Eyes Perceive Color
Symptoms of Red-Green Color Blindness
Causes
Diagnosis
Treatment
Coping
Red-green color blindness is the most common type of color blindness, a condition in which a person has limited ability to differentiate between certain colors. In red-green color blindness, this means difficulty distinguishing between shades of red, green, and yellow. Sharpness of vision typically is not affect. Color blindness is almost always inherited, in which case it cannot be treated, although there are ways for coping with it.
Color blindness is more common in men than in women: The condition affects one in 20 men versus one in 200 women.
What to Know About the Different Types of Color Blindness
The eye perceives color with a specific type of photoreceptor cell in theretinacalled a cone. (Photoreceptors are the cells that detect light; rods are the other type of photoreceptor cell.) Cones are concentrated in the center of the retina; besides perceiving color these cells make it possible to see fine details.
The retina has approximately 6 million cones. Each type of cone is sensitive to different wavelengths of visible light. There are three types of cone cells, each making up a certain percentage of the total cones in the retina:
Color blindness can occur when one or more of the cone types do not function properly.
Eric Audras/ GettyImages
The primary symptom of red-green color blindness is a diminished ability to see differences in red, green, and yellow. Most cases are mild; in fact, some people never realize they aren’t perceiving these colors as sharply as they could.
However, parents may notice early signs of color blindness in children:
Subclasses of Color BlindnessProtanopia: Only blue and green cones are functionalDeuteranopia: Only blue and red cones are functionalProtanomaly: Blue and some green cones are normal plus some anomalous green-like conesDeuteranomaly: Normal blue and some red cones are normal plus some anomalous red-like cones
Subclasses of Color Blindness
Protanopia: Only blue and green cones are functionalDeuteranopia: Only blue and red cones are functionalProtanomaly: Blue and some green cones are normal plus some anomalous green-like conesDeuteranomaly: Normal blue and some red cones are normal plus some anomalous red-like cones
The most common form of color blindness is inherited. Women can be carriers of hereditary forms of color deficiency that is passed through a defect in the X chromosome. However, because women have 2 copies of the X chromosome, women are not affected as frequently as men because their “normal” X chromosome compensates for the abnormal one. Female carriers of the abnormal gene can, however, pass on the defective X chromosome to their children, including their sons who will then manifest the condition. White men are disproportionately affected.
However, color blindness can be acquired, typically as a complication of diseases and conditions that affect the retina or the optic nerve, including:
The American Academy of Ophthalmology does not recommend routine testing for color blindness as part of routinecomprehensive eye exams.However, the conditions is easy to diagnose using a simple test called theIshihara test.
A.D.A.M.
There is no cure for inherited color blindness, but there are ways to cope with it if it is severe enough to interfere with everyday tasks. For example, if you drive it’s important to memorize the order of traffic lights. Other options:
EnChroma Glasses
EnChroma glasses feature tinted plastic lenses coated with nearly 100 layers of dielectric material that filters out specific wavelengths of light that overlap in red-green color blindness. Although EnChroma glasses do not improve color contrast enough that a person can pass a color blindness test, it does help people with color blindness get a taste of what it is like to have color vision.
EnChroma glasses aren’t a cure-all, nor will they appreciatively improve a person’s ability to distinguish color. At best they help people with color blindness better appreciate things like an orange blazer or a lavender flower petal. They also take about 30 minutes to take effect and are expensive.
A Word From Verywell
If you have color blindness, you’ve likely figured out ways to prevent it from interfering with your daily life. If you have a child you suspect may be color-blind, however, take them to a pediatric ophthalmologist for confirmation. The sooner you know the extent to which your child’s ability to distinguish between colors is impaired, the better able you’ll be to help them learn to deal with it.
7 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.National Health Service.Colour vision deficiency (colour blindness). Apr 1, 2019.American Academy of Ophthalmology.Cones. Dec. 19, 2018.Mukamal, R.How humans see in color. American Academy of Ophthalmology. June 8, 2017.Colour Blind Awareness.Spotting the early symptoms of colour vision deficiency in children.Tubert, D.What are the symptoms of color blindness?American Academy of Opthamology. Sept. 6, 2019.National Eye Institute: National Institutes of Health.Color blindness. July 3, 2019.Rauch, K.How color blindness is tested?American Academy of Ophthalmology. August 25, 2017.
7 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.National Health Service.Colour vision deficiency (colour blindness). Apr 1, 2019.American Academy of Ophthalmology.Cones. Dec. 19, 2018.Mukamal, R.How humans see in color. American Academy of Ophthalmology. June 8, 2017.Colour Blind Awareness.Spotting the early symptoms of colour vision deficiency in children.Tubert, D.What are the symptoms of color blindness?American Academy of Opthamology. Sept. 6, 2019.National Eye Institute: National Institutes of Health.Color blindness. July 3, 2019.Rauch, K.How color blindness is tested?American Academy of Ophthalmology. August 25, 2017.
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
National Health Service.Colour vision deficiency (colour blindness). Apr 1, 2019.American Academy of Ophthalmology.Cones. Dec. 19, 2018.Mukamal, R.How humans see in color. American Academy of Ophthalmology. June 8, 2017.Colour Blind Awareness.Spotting the early symptoms of colour vision deficiency in children.Tubert, D.What are the symptoms of color blindness?American Academy of Opthamology. Sept. 6, 2019.National Eye Institute: National Institutes of Health.Color blindness. July 3, 2019.Rauch, K.How color blindness is tested?American Academy of Ophthalmology. August 25, 2017.
National Health Service.Colour vision deficiency (colour blindness). Apr 1, 2019.
American Academy of Ophthalmology.Cones. Dec. 19, 2018.
Mukamal, R.How humans see in color. American Academy of Ophthalmology. June 8, 2017.
Colour Blind Awareness.Spotting the early symptoms of colour vision deficiency in children.
Tubert, D.What are the symptoms of color blindness?American Academy of Opthamology. Sept. 6, 2019.
National Eye Institute: National Institutes of Health.Color blindness. July 3, 2019.
Rauch, K.How color blindness is tested?American Academy of Ophthalmology. August 25, 2017.
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