Purpose: To determine the importance of the Ishihara test for the diagnosis of congenital dyschromatopsias and evaluate their incidence in a population of drivers, to assess the most common mistakes in the Color Box test and to study the relationship between dyschromatopsia, driving and traffic accidents. Methods: 523 drivers were examinated, in conformity with Contran resolution 734/89. The drivers were submitted to the color test with Ishihara plates, and those who had dyschromatopsia were submitted to the Color Box test (red, yellow and green), with LEDs as used in a traffic light. Results: An incidence of 5.5% (29 patients) of dyschromatopsias was observed. Of these patients, 3 were excluded from the study, 16 had severe disease and 10 had mild disease. In the latter group, 7 presented deuteranomaly and 3 protanomaly. Of those with deuteranomaly, 3 presented alterations in the Color Box test and 4 did not. Of those with protanomaly, 1 patient had abnormal results and 2 were normal. Of the patients with severe disease, 14 presented deuteranopia and 2 protanopia. All of them had an abnormal Color Box test. Conclusion: All patients with severe disease and half of those with moderate disease, made mistakes in the Color Box test. This study concludes that the Color Box test does not need to be performed in those patients who had the Ishihara Plate test done to diagnose congenital dyschromatopsias.
Color perception; Color vision defects; Color vision defects; Color perception tests; Automobile driving
