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Ishihara Color Vision Test

Take a free educational Ishihara Color Vision Test with 37 pseudoisochromatic plates. This screening tool helps raise awareness about red-green color vision differences but cannot replace professional medical evaluation.

37 Test Plates
Instant Results
Educational Only
Educational screening tool — not a medical diagnosisMedical disclaimer

IMPORTANT: This online Ishihara Color Vision Test is an educational screening tool only and is NOT intended for medical diagnosis, treatment decisions, or as a substitute for professional medical care. Results are affected by monitor settings, lighting, device variations, and other factors.

For accurate color vision assessment and medical advice, always consult a qualified eye care professional such as an optometrist or ophthalmologist. See our Medical Disclaimer for complete limitations.

Test ProgressPlate 1 of 37

Plate 1

Select the number you see

Ishihara Color Vision Test plate 1

What number or pattern do you see?

Background

About the Ishihara Color Vision Test

The Ishihara test is the most widely used color vision screening method in the world, and it has barely changed in over a century. Dr. Shinobu Ishihara published it in 1917 while working at the University of Tokyo, originally to screen military conscripts. The first edition used Japanese characters; Arabic numerals replaced them so the test could be used internationally, which is one reason it travelled so well — a plate that requires no shared language is unusually portable.

What "pseudoisochromatic" actually means

The term translates roughly as "falsely of the same color", and it describes the whole trick. Each plate is a field of dots in which the figure and the background are deliberately chosen to fall along a confusion line — a set of colors that a person with a specific deficiency perceives as equivalent. To someone with typical color vision the numeral separates cleanly from its surroundings. To someone whose red or green cone is missing or shifted, figure and ground become the same color, and the numeral simply isn't there.

The dots matter as much as the colors. Varying their size and brightness randomly prevents anyone from tracing the shape by lightness or edges instead of hue, which is what keeps the test measuring color vision rather than pattern recognition.

Why it only screens red-green

Every confusion line built into the standard plates lies on the red-green axis, because that is where inherited deficiency overwhelmingly sits. The consequence is a real blind spot: the Ishihara test does not reliably detect tritan (blue-yellow) deficiency, and it says nothing useful about achromatopsia. Blue-yellow loss needs a different instrument, which is why clinicians reach for arrangement tests such as the Farnsworth-Munsell family when they want to cover the whole hue circle.

Editions, and what this version is

The clinical test ships in several lengths — a full 38-plate edition, plus concise 24-plate and 14-plate versions used when time is short. The set here contains 37 educational plates. It is not the licensed clinical article, and it can't be: printed plates are manufactured to fixed ink reflectances and viewed under a standardized illuminant, whereas these are rendered by your own uncalibrated display in whatever light you happen to be sitting in.

Reference

Important Facts About the Ishihara Test

  • Red-Green Screening

    The Ishihara test primarily screens for red-green color vision differences including protanopia and deuteranopia. It does NOT reliably detect blue-yellow deficiencies or total color blindness.

  • Screening, Not Diagnosis

    This is a screening tool that raises awareness about potential color vision differences. It cannot diagnose medical conditions or measure severity precisely. Professional evaluation is required for diagnosis.

  • Common Condition

    Red-green color vision differences affect approximately 8% of men and 0.5% of women of Northern European descent. It is a hereditary condition typically passed through the X chromosome.

Plate types

The Five Kinds of Plate, and What Each One Is For

A plate set isn’t a single repeated puzzle. The classical test mixes several plate designs, each built to answer a different question.

The plate categories used in the classical Ishihara test and the purpose each one serves during screening.
Plate typeHow it behavesWhy it exists
DemonstrationReadable by essentially everyone, including people with severe deficiency.Confirms the person understands the task and can see the plate at all. It is not scored.
TransformationA person with typical color vision reads one numeral; someone with a deficiency reads a different one.The most informative design — reporting the “wrong” digit is positive evidence, not merely a failure to answer.
VanishingThe numeral is visible to typical color vision and disappears entirely for those with a deficiency.The plate most people picture when they think of this test. Simple, and the backbone of screening.
Hidden digitInverted: the numeral is visible only to people with a red-green deficiency, and typical viewers see nothing.A useful cross-check, because it is hard to fake in either direction.
ClassificationTwo figures presented together, read differently by protan and deutan observers.Attempts to distinguish which cone is affected rather than simply flagging that one is.

The mix matters because it makes the test hard to game. A vanishing plate can be failed by inattention, but a transformation plate that yields a specific alternative numeral, alongside a hidden-digit plate that yields a figure typical viewers cannot see, produces a pattern that is difficult to produce by guessing.

It also explains why a single missed plate means very little. Clinical scoring looks at how many plates were read correctly across the set and, on classification plates, at which way the errors fell. One stumble on one plate is noise; a consistent pattern across many is signal.

How it works

How Does the Ishihara Color Vision Test Work?

Reading the plates takes seconds each. What follows is what happens as you work through the set, and what the result can legitimately be used for.

  1. View Pseudoisochromatic Plates Look at circular patterns made of colored dots. Numbers or shapes are formed by dots of certain colors embedded in dots of different colors.
  2. Identify Numbers or Patterns People with normal color vision can distinguish the number from the background. Those with certain color vision differences may see a different number or nothing at all.
  3. Educational Awareness Results provide educational awareness about potential color vision differences but cannot diagnose medical conditions. Professional evaluation is necessary for accurate assessment.

FAQ

Frequently Asked Questions

What is the Ishihara Color Vision Test?

The Ishihara Color Vision Test is an educational screening tool designed to raise awareness about red-green color vision differences. It uses pseudoisochromatic plates (colored dot patterns) containing numbers or shapes. While based on Dr. Shinobu Ishihara's 1917 research, online versions are for educational purposes only and cannot provide medical diagnosis.

How accurate is the online Ishihara test?

Online Ishihara tests are educational screening tools with significant limitations. Accuracy is affected by monitor calibration, screen brightness, ambient lighting, device color profiles, and viewing conditions. The test screens for red-green color vision differences but does NOT detect blue-yellow deficiencies, cannot measure severity precisely, and cannot diagnose medical conditions. For accurate diagnosis, always consult a qualified optometrist or ophthalmologist.

What types of color blindness does the Ishihara test detect?

The Ishihara test primarily screens for red-green color vision differences, including protanopia (red-blind) and deuteranopia (green-blind). However, it does NOT reliably detect tritanopia (blue-yellow color blindness), cannot measure severity precisely, may not identify mild forms, and cannot detect achromatopsia (total color blindness). It is a screening tool, not a comprehensive diagnostic test.

Can the Ishihara test diagnose color blindness?

No. The Ishihara test is a screening tool, not a diagnostic test. Online versions are for educational awareness only and cannot diagnose color blindness or any medical condition. Professional diagnosis requires examination by a qualified eye care specialist using properly calibrated equipment, controlled lighting conditions, and comprehensive testing. If you have concerns about your color vision, consult an optometrist or ophthalmologist.

What should I do if I have difficulty with this test?

Remember that online tests are educational tools with many limitations. Difficulty with an online test does not mean you have color vision deficiency. Many factors affect results including screen quality, lighting, and fatigue. If you have concerns about your color vision, schedule an appointment with a qualified eye care professional (optometrist or ophthalmologist) for proper evaluation using standardized equipment and controlled testing conditions.

Can children take the Ishihara Color Vision Test?

Children who can read numbers can take this test. For younger children who cannot read yet, try our Kids Color Vision Test that uses shapes instead of numbers. However, remember that online tests are for educational purposes only. If you have concerns about a child's color vision, consult a pediatric optometrist or ophthalmologist.

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