What is color blindness?
If you have color blindness (color vision deficiency), it means you see colors differently than most people. Most of the time, color vision deficiency makes it hard to tell the difference between certain colors.
Usually, color vision deficiency runs in families. There’s no cure, but special glasses and contact lenses can help people see differences between colors. Most people who have color vision deficiency don’t have problems with everyday activities.
What are the types of color vision deficiency?
The most common type of color vision deficiency makes it hard to tell the difference between red and green. Another type makes blue and yellow look the same. In rare cases, people have complete color vision deficiency, which means they don’t see color at all.
What are the symptoms of color vision deficiency?
The main symptom of color vision deficiency is not seeing colors the way most people do. If you have color vision deficiency, you may have trouble seeing:
- The difference between colors
- How bright colors are
- Different shades of colors
Symptoms of color vision deficiency are often so mild that they’re hard to notice. That’s why many people with color vision deficiency don’t know they have it. And people usually adjust to differences in how they see color.
People with very serious cases of color vision deficiency might have other symptoms, too — like quick side-to-side eye movements (nystagmus) or sensitivity to light.
Am I at risk for color vision deficiency?
Men have a much higher risk than women for color vision deficiency. You’re also more likely to have color vision deficiency if you:
- Have a family history of color vision deficiency
- Have certain eye diseases
- Have certain health problems, like diabetes, Alzheimer’s disease, or multiple sclerosis (MS)
- Take certain medicines
- Are white
If you think you may have color vision deficiency, talk with your eye doctor about getting checked.
When to get your child’s eyes tested
It can be tricky to diagnose color vision deficiency in children. Kids who have color vision deficiency may try to hide it. But having color vision deficiency can make it hard to read from a chalkboard or do other activities, so get your child’s eyes tested if you’re concerned.
Get your child’s eyes tested if they have a family history of color vision deficiency or if they seem to be having trouble learning colors.
Ask your child’s eye doctor to test them. You also may be able to get your child’s eyes tested at school.
What causes color vision deficiency?
Most people who have color vision deficiency are born with it. This is because the most common types of color vision deficiency are genetic, meaning they’re passed down from parents.
Color vision deficiency can also happen because of an injury to the retina (the light-sensitive layer of tissue in the back of the eye), the optic nerve (which connects the eye to the brain), or the brain itself. Some examples of injuries that can lead to color vision deficiency are:
- Retinal detachment (when the retina is pulled away from its normal position at the back of the eye)
- Eye injuries caused by lasers
- Some kinds of brain tumors — especially ones that affect the optic nerve or put pressure on the brain
- Radiation treatments
Color vision may also get worse as you get older — often because of cataracts (cloudy areas in the lens of the eye).
Did you know?
Everyone sees color a little differently — including people who don’t have color vision deficiency
About 1 in 12 men have color vision deficiency
Most people with color vision deficiency are born with it, but sometimes it doesn’t show up until later in life
How can I find out if I have color deficiency?
Your eye doctor can usually use a simple test to tell you if you have color vision deficiency.
During the most common type of test, your eye doctor will show you a circle made of many different colored dots. The circle has a shape inside it that’s also made of dots — like a number, a letter, or a squiggly line. This shape is easy to see if you don’t have color vision deficiency, but people with color vision deficiency have a hard time seeing it.
What's the treatment for color vision deficiency?
There’s no cure for color vision deficiency that’s passed down in families (inherited), but most people adjust to it. Children with color vision deficiency may need help with some classroom activities, and adults with color vision deficiency may need accommodations to do jobs that rely on telling the difference between colors, like being a graphic designer.
If your color vision deficiency is happening because of another health problem, your doctor will treat the condition that’s causing the problem. If you’re taking a medicine that causes color vision deficiency, your doctor may adjust how much you take or suggest you switch to a different medicine.
If color vision deficiency is causing problems with everyday tasks, talk with your eye doctor about available options, like:
Glasses and contacts. Special contact lenses and eyeglasses may help people who have color vision deficiency tell the difference between colors. They work by increasing the contrast between colors so they’re easier to tell apart.
Visual aids. Apps let people take photos with a phone or tablet and then tap on part of the photo to find out what color it is.
What is the latest research on color vision deficiency?
Research studies suggest that gene therapies (treatments that change genes in a target location) are promising for a severe type of color vision deficiency.