[The pathogenesis of diabetic dyschromatopsia]

Essential data about the physiology of colour vision are reminded, with a stress layed on the possible contribution of the rodes in perception of blue and green colours. The main features of the diabetic dyschromatopsia are reviewed, together with their pathomorphological support and the two existing theories regarding its pathogenesis: vascular origin versus neuronal origin of the defect. The contribution of the photocoagulation to these alterations is also discussed.