Color Plates
Interactive colour-vision screening with automated scoring.
For educational purposes only. A teaching and screening aid, not a medical device; it does not replace a standard clinical examination.
How to use
- Test each eye separately, with the patient’s near correction, at a comfortable reading distance. Use full screen brightness, with no night-shift or blue-light filter, in good room light.
- Ask the patient to read the number on each plate, and allow a few seconds per plate.
- Swipe right (or press →, or Correct) when the answer is right, and swipe left (or press ←, or Incorrect) when it is wrong. Hold “Show answer” to see the expected answer privately.
- Plates 1–4 are controls and are not scored. Plates 1–3 differ in brightness as well as colour, so everyone with adequate acuity reads them; plate 4 has no number at all, so the right answer is “nothing”. Plates 5–14 are the ten test plates.
How it is scored
- The control plates are never counted, as with Ishihara’s demonstration plate and HRR’s four demonstration plates (three visible to everyone and one blank). Their job is to make the test valid: if any control is missed, the run is reported as not valid and the test plates are not interpreted. A number reported on the blank plate points to guessing or a memorised sequence.
- The score is the number of the ten test plates read correctly, out of 10, with the red–green (8 plates: 4 protan-axis, 4 deutan-axis) and blue–yellow (2 tritan-axis) counts shown separately — the same 4 : 2 balance as the HRR screening series.
- Screening outcome, as in the HRR screening series: all 10 test plates read is a pass (no colour deficiency detected on this screen); any test plate missed is a fail, to be confirmed with a standardised test. Type and severity are not graded: these plates are original and not validated for that.
Limitations
- These are OcuLearning’s own generated plates, not Ishihara or HRR plates, and are for education and screening only. Confirm any abnormal result with a standardised test (Ishihara, HRR) under proper illumination, or with an anomaloscope.
- The colours are calculated for an ideal sRGB display. Real screens differ, so the plates are only approximately invisible to dichromats and may be easier or harder than intended.
- The tritan plates are the least robust to display differences.
References
- Viénot F, Brettel H, Mollon JD. Digital video colourmaps for checking the legibility of displays by dichromats. Color Res Appl 1999;24:376-381.
- Regan BC, Reffin JP, Mollon JD. Luminance noise and the rapid determination of discrimination ellipses in colour deficiency. Vision Res 1994;34:1279-1299.
- Machado GM, Oliveira MM, Fernandes LAF. A physiologically-based model for simulation of color vision deficiency. IEEE Trans Vis Comput Graph 2009;15:1291-1298.
- Birch J. Efficiency of the Ishihara test for identifying red-green colour deficiency. Ophthalmic Physiol Opt 1997;17:403-408.
- Bailey JE, Neitz M, Tait DM, Neitz J. Evaluation of an updated HRR color vision test. Vis Neurosci 2004;21:431-436.
For educational purposes only. The Clinical Exam tools are part of an educational platform. They are screening and teaching aids, not certified medical devices: a result depends on the screen (letter sizes are estimated for the type of device), the lighting and the testing distance. They are not a diagnosis, and any abnormal or doubtful result should be confirmed with a standard clinical test.