Medical Disclaimer
This site provides a screening test, not a diagnosis. It cannot replace an eye examination, and no result here should be used to make a medical, occupational or educational decision.
Last updated September 4, 2026
Not Medical Advice
The content on this site is published for general information and education. It is not medical advice, and reading it or using the test does not create a doctor and patient relationship. We are not physicians, optometrists or optometric technicians, and we do not present ourselves as any of those.
Why an Online Test Has Limits
A clinical color vision assessment controls the things that change the answer. Ours cannot control any of them.
- Your display is not calibrated. Two monitors showing the same plate can produce measurably different colors at the eye.
- Your lighting is unknown. A printed test is administered under daylight balanced illumination. Tungsten light shifts everything towards red and produces false passes on the red plates.
- Night mode and blue light filters change the result. Left on, they can produce a blue yellow pattern in someone with entirely normal color vision.
- Nobody is timing you. The printed test allows about three seconds per plate. Given longer, people reason their way to an answer instead of reporting what they see, which produces a pass that means nothing.
- Both eyes at once. A clinical test can examine each eye separately, which is how a change in one eye is caught.
What This Test Can Tell You
Used properly, an Ishihara style plate test answers one question well: is a color vision deficiency likely, and which cone axis does it sit on. That is genuinely useful. It is the reason plate tests are still the standard first line screen more than a century after they were published.
What It Cannot Tell You
- Severity. The number of plates missed correlates loosely with severity. It is not a grade. Grading needs an anomaloscope.
- Missing cone or mistuned cone. Separating deuteranopia from deuteranomaly is largely beyond a plate test.
- Cause. A plate test cannot tell inherited color blindness from color vision loss caused by disease or medication.
- Anything official. Occupational and licensing standards are assessed in person with printed plates, a lantern test or an anomaloscope. A screenshot of this page is not evidence.
When to See an Eye Care Professional
Book an appointment promptly if your color vision has changed, is getting worse, or is different in each eye. Inherited color blindness does none of those things. It is fixed, identical in both eyes and present from birth. A change is a symptom, and the causes include glaucoma, diabetic retinopathy, macular degeneration, optic nerve disease and side effects of certain medications. Several of those are treatable, and catching them early matters.
Also worth an appointment:
- A result that will affect a job, a licence, military service or a child's schooling. Get it confirmed properly.
- Color vision trouble alongside blurred vision, eye pain, floaters, halos or loss of part of your field of view.
- Any concern about a child's vision. Screening in childhood is quick, routine and worth doing.
In an Emergency
Sudden loss of vision, sudden loss of color vision in one eye, or severe eye pain needs urgent care. Contact your local emergency service or an eye casualty department. Do not wait, and do not use this site to decide.
Accuracy of Content
We take accuracy seriously and cite the basis for the technical claims we make, as set out on the about page. Even so, published understanding changes, and errors are possible. If you find one, please tell us. Nothing here should be treated as a final authority on your own vision.