What it is
Color blindness, also called color vision deficiency, means a person sees some colors differently from most people. It rarely means seeing only in black and white. Most often it affects how easily certain colors can be told apart, especially when they are similar in brightness.
The main types are grouped by the cone cells involved. Protan types involve the red-sensing system, and deutan types involve the green-sensing system. Both are commonly called red-green color blindness. Tritan types involve the blue-sensing system and can affect blues, greens, yellows and purples. Each type can range from mild to more significant.
Rarer forms include achromatopsia, where color vision is greatly reduced or absent and other visual differences are often present. Some types are inherited and present from birth. Red-green types are more common in men. Others can be acquired later in life, for example in connection with certain eye conditions, health conditions or medications. A licensed professional can help sort out which applies.
How it’s traditionally been approached
Color blindness has traditionally been identified with screening and testing tools. These include plate-style tests made of colored dots, and arrangement tests where colors are put in order. Some clinics also use an instrument called an anomaloscope, which can help tell types and severity apart.
People have long used practical strategies, such as labeling clothing, using color names or patterns, relying on brightness differences, and using phone or computer accessibility settings. Many people with mild forms adapt so well they learn about it only when tested.
Color-enhancing filter glasses and contact lenses are also sold. They do not cure color blindness and do not restore normal color vision. How well they work varies with a person's specific type (protan, deutan or tritan) and severity, and some people notice little change. They are not suitable or helpful for everyone, so it is reasonable to ask a licensed provider about them.
How the right doctor may help
The right provider, such as an eye doctor with experience in color vision, may help you understand which type you have and how significant it is. A visit often starts with questions about your history, your family, your health and any medications. It may then include one or more color vision tests, plus a general eye exam.
Comprehensive color vision testing may give a clearer picture than a quick screening. A genetic and acquired color vision evaluation may help show whether the difference has been lifelong or appeared more recently. This matters because a change in color vision can sometimes relate to another health issue, and only a clinician can say what it means for you.
Helpful questions to ask include: Which type do I appear to have, and how severe is it? Could it be inherited or acquired? How might it affect school, work or daily tasks? Are color-enhancing glasses or lenses appropriate for my type, and what is their regulatory status? Do my career goals have color vision requirements I should confirm?
The whole-person view
Body, mind and stress affect each other, and that includes how we experience vision differences. Being unable to tell certain colors apart can bring frustration, embarrassment or worry in classrooms, workplaces or hobbies. Those feelings are common, and they deserve the same attention as the practical side.
Some people find that body-based support, such as the approaches listed through Somatic Experiences, helps them work with stress. Others prefer talking with a licensed counselor, such as those found through Therapists.plus. Both are optional ways to support the whole person alongside an eye care visit.
Keep in mind
- Educational only, not medical advice: only a licensed clinician can evaluate your color vision and tell you which type, if any, you have.
- Color-enhancing glasses and contact lenses do not cure color blindness or restore normal color vision, and results vary by type and severity.
- A sudden change in color vision, or one that comes with other vision symptoms, should be checked promptly by a licensed professional; for emergencies call 911, and in a crisis call or text 988.
- Career color vision standards (such as aviation, military, law enforcement, commercial driving, electrical trades and maritime) vary and change, so confirm current requirements with the employer, licensing body or agency.
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Frequently asked questions
What are the main types of color blindness?
The main types are red-green (protan and deutan), blue-yellow (tritan), and complete color blindness (achromatopsia). Protan involves the red-sensing system, deutan the green, and tritan the blue. Each can vary from mild to more significant.
What is the most common type of color blindness?
Red-green color blindness is the most common group, and it is more common in men than in women. Deutan types are generally the ones people hear about most. Blue-yellow and total color blindness are much less common.
What is the difference between protan and deutan color blindness?
Protan types involve the red-sensing cones, while deutan types involve the green-sensing cones. Both can make reds, greens, browns and oranges hard to tell apart, though the colors can look somewhat different. A color vision test from a licensed provider can help tell them apart.
Can you be color blind to blue and yellow?
Yes, this is called tritan color blindness. It can make blues and greens, or yellows and pinks, harder to distinguish. It is less common than red-green types, and it can sometimes be acquired later in life, so an eye care evaluation is worthwhile.
Are the types of color blindness inherited?
Many types are inherited and present from birth, and red-green types are more common in men. Color vision changes can also be acquired later because of eye conditions, other health issues, or some medications. A clinician can help work out which applies to you.
Do color blind glasses work for every type of color blindness?
No. Color blind glasses, meaning color-enhancing filter glasses, do not cure color blindness or restore normal color vision. How much they help varies by your type (protan, deutan or tritan) and severity, and some people notice little benefit. Ask a licensed provider whether they are appropriate for you and what their regulatory status is.
Educational resource. Colorblind Glasses shares general information and connects people with independent doctors. It is not medical advice, diagnosis or treatment. Talk with a licensed professional about your health.