What it is
The Ishihara test is a set of plates, each made of many colored dots. Within the dots is a number or a winding line that people with typical color vision can usually see. People with certain types of color vision deficiency may see a different number, or none at all.
The test is mainly designed to screen for red-green color vision deficiency, the most common general category of color blindness. It is a screening tool, which means it can suggest that something may be going on, but it is not the same as a full evaluation.
Versions exist for people who cannot read numbers, such as young children, using shapes or paths to trace instead. The test is usually done in good, consistent lighting, and the way the plates are presented can affect how reliable the results are.
How it’s traditionally been approached
For many decades, the Ishihara test has been one of the most common first steps in color vision screening. It is quick, inexpensive to administer, and easy to use in schools, clinics, and workplaces.
Because it focuses on red-green differences, it is generally not designed to detect blue-yellow (tritan-type) color vision problems. Other tests are traditionally used to look at those, and to estimate how mild or strong a deficiency may be.
Some careers and training programs have historically used color vision screening as part of their requirements. Standards vary by employer and licensing authority and change over time, so it is best to confirm current requirements directly with the specific employer, licensing body, or agency.
How the right doctor may help
A licensed eye care professional may start by asking about your history, your family's history, and any difficulties you notice with color. They may use the Ishihara plates along with other tests that look at different types of color vision, such as protan, deutan, or tritan patterns, and how severe they are.
A visit is generally a calm, simple experience. You look at plates or arrangements of colors and describe what you see. Comprehensive color vision testing may offer more detail than a single screening, and pediatric color vision testing is geared toward making the process comfortable for children.
Helpful questions to ask include: What type of color vision difference do my results suggest? How mild or strong is it? Do I need additional testing? What does this mean for school, work, or daily life? If you are curious about color-enhancing filter glasses or contact lenses, ask whether they might be appropriate. These do not cure color blindness and do not restore normal color vision, and how well they work varies with a person's specific type and severity. Only a licensed clinician can decide what is appropriate for you after an evaluation.
The whole-person view
Color vision is part of how the whole person experiences the world. Learning that you or your child sees color differently can bring up a mix of curiosity, relief, frustration, or worry, and stress and mood can in turn affect how we cope with everyday tasks. Body, mind, and emotions influence each other.
If the news leaves you feeling anxious or stuck, body-based support such as Somatic Experiences may appeal to some people, and talk therapy through Therapists.plus may help others work through feelings about a new result. Neither is a substitute for an eye exam, and many people simply find clear information and a supportive doctor is all they need.
Keep in mind
- The Ishihara test is a screening, not a full diagnosis; only a licensed professional can interpret your results.
- Color-enhancing filter glasses and contact lenses do not cure color blindness or restore normal color vision, and results vary by type and severity.
- Career and licensing color vision standards vary and change, so confirm current requirements with the employer, licensing body, or agency.
- Licensed professionals should guide care. For emergencies call 911; in a crisis call or text 988.
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Frequently asked questions
What is the Ishihara test?
The Ishihara test is a color vision screening that uses plates of colored dots hiding numbers or paths. It is mainly used to check for red-green color vision deficiency. It is a screening tool and not a complete diagnosis.
Can the Ishihara test diagnose color blindness?
No, the Ishihara test alone does not diagnose color blindness. It can suggest that a color vision difference may be present. A licensed eye care professional can use additional testing to understand the type and severity.
Does the Ishihara test detect all types of color blindness?
No, it is mainly designed to screen for red-green color vision deficiency. It is generally not meant to detect blue-yellow (tritan-type) differences. Other tests are traditionally used for those.
Can I take the Ishihara test online?
You can find online versions, but they may not be reliable because screens vary in color and brightness. A test given by a licensed professional under proper lighting is generally more dependable. Ask an eye care provider if you want accurate results.
Can color blind glasses help me pass the Ishihara test?
Color blind glasses do not cure color blindness or restore normal color vision, and effects vary by the person's type (protan, deutan, or tritan) and severity. Whether they are appropriate is a decision for a licensed clinician after an evaluation. For any career or licensing test, confirm the current rules with the employer or agency.
Is there a version of the Ishihara test for children?
Yes, there are versions that use shapes or lines to trace instead of numbers, which suits children who don't yet read numbers. Pediatric color vision testing providers are used to making the process comfortable for kids. A doctor can recommend when testing may be appropriate.
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.