comparison of color vision between patients with type ii diabetes mellitus and normal subjects

purpose: to evaluate color vision in patients with type ii diabetes mellitus without diabetic retinopathy and compare the results with those of age- and sex- matched normal individuals. methods: this descriptive, comparative study was conducted on 100 diabetic patients without any sign of retinopathy and 100 age- and sex-matched normal subjects. color vision was evaluated using ishihara and farnsworth d-15 color vision tests. results: farnsworth d-15 color test showed that 26% of diabetic patients and 3% of normal subjects had color vision defect. using ishihara test, 3% of the subjects in each group had color vision defect. conclusion: d15 color test revealed a color vision defect in spite of the normal retinal appearance in diabetic patients. it means that functional changes may be detected with proper color vision test before any structural changes in retina. we recommend farnsworth d-15 test for this purpose.