Color Blind Test - QTKTest
The Color Blind Test helps you screen for red-green, blue-yellow, or total color blindness. Free, no registration, and designed for all ages.
Test Instructions
Color Vision Guide
What is Color Blindness?
Color Blindness is a condition where a person has difficulty distinguishing certain colors. The most common form affects red–green discrimination (protan and deutan). Less common are blue–yellow (tritan) deficiency and very rare total color blindness (achromatopsia). You can also try this online assessment for a quick check.
Accuracy and Limitations
Ishihara is a screening test, not a full diagnosis. Reported screening performance is high under proper conditions (e.g., 12/14 pass threshold ~97% sensitivity and ~100% specificity). Accuracy depends on the number of plates, neutral lighting, screen brightness, and proper administration.
Color Blind Test FAQ
What is the Ishihara Color Blind Test?
The Ishihara color blind test is a screening test for red–green Color Blindness that uses pseudo‑isochromatic plates composed of colored dots forming numbers or paths. People with normal color vision identify the figure; those with red–green deficiency may see a different figure or none at all.
Does the Ishihara test detect all types of color blindness?
Mainly red–green deficiency (protan and deutan). It does not reliably detect blue–yellow deficiency (tritan) or fully assess achromatopsia. Clinical testing is required to classify subtypes and severity.
How accurate is the Ishihara test?
Studies report high screening performance. Using a pass threshold of 12 correct out of 14 plates, sensitivity can reach around 97% and specificity 100%. Accuracy depends on number of plates, lighting, and administration conditions (source: Wikipedia – Ishihara test).
How many questions and timing does this online test use?
This site uses 10 questions selected randomly from a fixed image set, with 7 seconds per question to balance focus and pace. Standard Ishihara booklets may include 38 plates or shortened versions of 10, 14, or 24 plates.
Can online results replace medical diagnosis?
No. Online tests are screening tools. If your result suggests Color Blindness, consult an eye care professional for comprehensive evaluation (ref: ColorBlindnessTest.org guidance).
Why are the answer options fixed to digits 0–9?
For consistent, fast interaction across questions. Our current image set uses single‑digit targets; fixed options avoid cognitive load from changing layouts and do not affect scoring integrity.
Why are answer buttons disabled until the image fully loads?
To prevent mis‑clicks and ensure the plate is clearly visible before you respond. The overlay spinner disappears once the image loads or if loading fails, then options become selectable.
How is the score calculated and how are results interpreted?
Score = correct answers ÷ total questions × 100. Interpretation: ≥90 Normal color vision; ≥70 Mild Color Blindness; ≥50 Moderate Color Blindness; otherwise Severe Color Blindness. These are indicative ranges for user guidance, not clinical grades.
What testing conditions do you recommend?
Increase screen brightness, avoid tinted lenses, view in neutral lighting, and answer promptly. These recommendations align with common Ishihara administration guidance to reduce lighting and display bias.
Does this test identify red–green subtypes (protan vs deutan)?
This simplified online test reports overall accuracy and a red–green score. It does not classify subtype. Dedicated diagnostic plates and clinical instruments are required for subtype and severity classification.
Can I retake the test and will questions repeat?
You can retake the test anytime. Each run randomly selects 10 images from the dataset, so question order varies and repetition is minimized.
Are there plates that show different figures to color‑deficient viewers?
Yes. Ishihara includes vanishing, transformation, hidden‑digit, and diagnostic plates. Some figures appear only to those with red–green deficiency, while others vanish for them (see Ishihara test references).
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