3.8.5 Variability within congenital colour deficiency3.8.6 Effect of ambient illumination and stimulus size on colour sensitivity in normal trichromats and in congenital ...; 3.8.7 Effect of background luminance on colour thresholds in congenital colour deficiency; 3.9 Colour in occupational environments; 3.9.1 Current occupational colour vision requirements; 3.9.2 The need to quantify the severity of colour vision loss; 3.9.3 Setting minimum colour vision requirements; 3.10 Colour in healthcare; 3.10.1 Patterns of colour vision loss in retinal disease; 3.10.2 Impact in vision healthcare