BRIGHTNESS MATCHING AND COLOR DISCRIMINATION IN YOUNG DIABETICS WITHOUT RETINOPATHY

This study used the methods of the Farnsworth-Munsell 100-hue test (FM -100), heterochromatic brightness matching (HBM) and wavelength discri mination to test the sensitivity and colour vision of 20 juvenile diab etics with no (16) or very mild (4) retinopathy. Their results were co mpared to an age-matched control group. The FM-100 results showed a si gnificant increase in error scores throughout the spectrum in comparis on to the controls. This deterioration in colour vision was confirmed in the results for the wavelength discrimination task, tested between 440 and 640 nm, where the just noticeable difference in colour was, in general, larger for the diabetic group than the control group. Only a t 460 nm were the results of the diabetics similar to those of the con trols. The diabetic group were also less sensitive than the control gr oup in the HBM task between 480 and 600 nm. The results show that a de ficit in sensitivity and colour vision occurs in diabetics before the onset of a clinically visible retinopathy.