Farnsworth D-15 Color Arrangement Test
Put 15 colours in order, starting from the fixed cap. People with a colour vision deficiency mix up caps from opposite sides of the colour circle, and the pattern of mistakes points to the type.
Tap the loose cap that is closest in colour to the last cap in your sequence. Keep going until all 15 are placed. You can also drag caps into place, or back to the loose caps.
Your sequence
Loose caps
How to do the test
- Look at the fixed cap at the start of your sequence.
- From the loose caps, tap the one closest in colour to the last cap in your sequence.
- Repeat until all 15 are placed. Tap a placed cap to take it back.
- Tap “See my result”.
How the result is worked out
A perfect order follows the colour circle. We score your order with the method of Vingrys and King-Smith. The confusion index compares your errors with a perfect arrangement: 1.0 is perfect and 1.6 or more counts as a fail. The confusion angle shows the direction of your mistakes, which differs for protan, deutan and tritan deficiencies.
The D-15 is designed to pass people with mild deficiencies and catch moderate to strong ones. A pass here does not rule out a mild deficiency.
Questions about the D-15 test
Is this the same as the clinical D-15?
It uses the same task and the same scoring, but the clinical test uses physical caps under a standard daylight lamp. Screen colours vary, so treat this as a screening aid.
What does a failed D-15 mean?
It suggests a moderate or strong colour vision deficiency. Occupational exams often use the D-15 after a failed plate test, so see an optometrist for a clinical test if the result matters for work.
Sources
- Vingrys AJ, King-Smith PE. A quantitative scoring technique for panel tests of color vision. Investigative Ophthalmology & Visual Science. 1988;29(1):50-63. pubmed.ncbi.nlm.nih.gov
- National Eye Institute. Color Blindness. nei.nih.gov
Want to know your type and severity? Take the 20-plate test.
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