Background & objectives: Colour vision defects associated with ocular disease have been reported since the 17th century. Objectives were to study prevalence of colour vision abnormalities associated with diabetic retinopathy & to study the type of colour vision defect associ–ated with diabetic retinopathy. Methods: A longitudinal descriptive study was conducted.70 patients diagnosed with Diabetic Retinopathy were selected. Colour vision was tested by using Ishihara & HRR Pseudoisochromatic charts. Results: When Evaluated using HRR plates 29 (41.42%) patients were found to have colour vision impairment. Among them 20 (68.96%) patients had colour vision impairment of the blue–yellow axis purely & 3(10.34%) patients of red–green axis purely & 6(20.70%) patients of both axis. Interpretation & conclusions: Colour vision especially of the blue–Yellow axis was found to be affected in this study. Colour vision and visual testing can be used as cheap, quick, non–invasive, portable tool for screening of diabetic retinopathy.