Poor Color Vision – Symptoms and Causes
Overview
Color blindness affects how people see certain colors. Despite its name, most people with this condition don’t see the world in black and white. The correct medical term is color vision deficiency.
This condition typically runs in families through genetic inheritance. Men have a higher chance of being born with color blindness than women.
The most common type makes it difficult to distinguish between red and green shades. A less frequent form affects the ability to differentiate between blue and yellow colors.
Color vision problems can also develop from:
- Eye diseases
- Side effects of certain medications
Most people with color blindness lead normal lives by finding ways to work around their condition. Many aren’t even aware they have it until tested, as they’ve always seen colors in that particular way.
Signs of Color Vision Problems
Color vision problems may go unnoticed for years. Many people discover their condition only when they have trouble telling colors apart, such as when driving or using colored materials for learning or work.
People with color vision deficiencies might have difficulty seeing:
- Various shades of red and green
- Different tones of blue and yellow
- All colors in severe cases
Most commonly, people struggle with red and green shades. It’s important to note that someone with a red-green or blue-yellow deficiency usually isn’t completely unable to see both colors. These vision issues range from mild to severe.
When You Should Visit an Eye Doctor
If you notice trouble telling colors apart or experience changes in your color vision, schedule an appointment with an eye specialist for proper testing.
Parents should make sure children receive complete eye exams that include color vision screening before they begin school.
While inherited color vision problems have no cure, color vision difficulties caused by illnesses or eye conditions may improve with treatment of the underlying cause.
Causes
Color vision depends on the way your eyes process light. When light enters your eye, it follows a path through several eye parts:
- Cornea – the clear front part of your eye.
- Lens – helps focus light.
- Vitreous humor – the clear gel filling your eye.
The light then reaches special cells called cones in the retina at the back of your eye.
These cones detect different wavelengths of light:
- Short wavelengths (blue light)
- Medium wavelengths (green light)
- Long wavelengths (red light)
When working properly, these cones send signals through your optic nerve to your brain, which interprets them as colors. Your brain combines these signals to create the full range of colors you see.
If any of these cone types don’t work correctly, you won’t be able to tell certain colors apart. This happens when the cones fail to react properly to specific wavelengths of light.
Risk Factors
Several things can increase your chance of having color blindness:
- Gender Differences: Men are much more likely to have color blindness than women.
- Family Connections: Color blindness often runs in families. You might inherit a mild, moderate, or severe form. When inherited, it usually affects both eyes equally and stays the same throughout your life.
- Health Conditions: Many diseases can cause color vision problems. These include diabetes, sickle cell anemia, and macular degeneration, among others. With disease-related color blindness, one eye may be worse than the other. Your color vision might improve if the underlying condition can be treated.
- Medications: Some drugs can change how you see colors. For example, hydrochloroquine, used for rheumatoid arthritis, may affect color vision.
- Eye Injuries: Damage to your eyes from accidents, surgery, radiation therapy, or laser treatments can cause color blindness.
