Color Blindness – Symptoms and Causes

Overview

Color blindness, or color vision deficiency, is a condition that affects how people perceive certain colors. Most people with this condition don’t see the world in black and white. True color blindness of this type is uncommon.

Most individuals with color vision deficiency have trouble distinguishing between specific color combinations. The most common form affects red-green perception, making these colors difficult to tell apart. A less frequent type involves blue-yellow color confusion.

The condition varies in severity. Some people experience mild difficulties distinguishing similar shades, while others have more significant perception challenges.

Symptoms of Color Vision Issues

Color vision problems can exist without your knowledge. Sometimes, people discover this condition when they face confusion, like trouble telling apart traffic light colors or working with color-coded materials.

People with color vision deficiencies might have difficulty distinguishing:

• Red and green shades
• Blue and yellow shades
• All colors

Most commonly, people struggle with red and green shades. Those affected typically aren’t completely unable to see both colors. The severity varies from mild to severe cases.

When Medical Help Is Needed

If you notice problems distinguishing certain colors or experience changes in your color vision, it’s important to visit an eye specialist for proper testing.

Parents should ensure their children receive complete eye examinations, including color vision tests, before they begin school.

While inherited color vision problems have no cure, treatment may improve color vision if the cause is illness or eye disease.

Causes

Color vision depends on how light interacts with specialized cells in your eyes.

The process starts when light enters through the cornea, passes through the lens, and travels through the clear vitreous fluid to reach the back of your eye.

At the retina’s macular area, three types of cone cells detect different wavelengths:

• Short wavelength cones respond to blue light
• Medium-wavelength cones detect green light
• Long wavelength cones sense red light

When light hits these cones, chemical reactions occur that send color information through your optic nerve to your brain for processing. Your brain interprets these signals as the colors you see.

Color vision deficiency happens when one or more types of cone cells don’t function properly. This prevents you from distinguishing certain colors correctly.

For example, if your red-detecting cones don’t work normally, you’ll have trouble telling red colors from others. The same applies to green and blue cone deficiencies.

Risk Factors

Several factors can increase a person’s chances of having color blindness:

• Gender: Men are much more likely to have color blindness than women.
• Genetics: Color blindness often runs in families. People can inherit mild, moderate, or severe forms. When inherited, color blindness usually affects both eyes equally. It also stays the same throughout life.
• Health Conditions: Many diseases can cause color vision problems, including diabetes, sickle cell anemia, and macular degeneration. Other diseases that can cause color blindness are Alzheimer’s disease, multiple sclerosis, and glaucoma.
  • Parkinson’s disease, chronic alcoholism, and leukemia can also lead to color vision problems. With disease-related color blindness, one eye may be worse than the other. If doctors can treat the disease, color vision might improve.
• Medications: Some drugs can affect how people see colors. For example, hydrochloroquine, used for rheumatoid arthritis, can change color vision.
• Eye Damage: Injuries to the eye can cause color blindness. This includes damage from accidents, surgery, radiation therapy, and laser treatments.