Correlation between parameters estimated by the colour assessment and diagnosis and the Cambridge colour test in
Joycianne Rodrigues Parente1, Eliza Maria da Costa Brito Lacerda2, Dora Fix Ventura3
1Núcleo de Teoria e Pesquisa do Comportamento, Universidade Federal do Pará, Belém, Brazil.
Abstract:
The Colour Assessment and Diagnosis (CAD) and the Cambridge Colour Test (CCT) are computerized psychophysical tests widely used in the diagnosis of color vision deficiencies due to their high specificity and sensitivity. However, these tests differ substantially in the type of visual task, stimulus configuration, vectors, luminance, background composition, and presentation time. This study aimed to compare the evaluation parameters estimated by these tests in trichromatic and dichromatic individuals. A total of sixty-six participants (40 trichromats and 38 dichromat individuals -16 protans and 22 deutans; mean age: 26.3 ± 8.9 years) were evaluated. Color discrimination thresholds were fitted to elliptical functions, and parameters such as ellipse area, rotation angle, and the size of protan, deutan, and tritan vectors were analyzed. Results showed equivalence between the tests for: the deutan and tritan vector areas and sizes in the trichromat subgroup; tritan vector area and size in the protan subgroup; and protan and tritan vector sizes in the deutan subgroup. Differences in the central coordinates of the CAD and CCT tests and the spatial arrangement of vectors in the CIE 1976 color space (specific to the CCT test) may have influenced the results. Nonetheless, agreement was observed in the measures of ellipse area, rotation angle, and sizes of the protan and tritan vectors between the two tests. These findings suggest that, despite methodological differences, the CAD and CCT tests produce largely comparable results and can be considered complementary tools in the assessment of color discrimination in clinical and research settings.
