Colour vision and dark adaptation in high myopia without central retinal degeneration.

Colour vision and dark adaptation of 36 high myopes (68 eyes) without degenerative fundus changes were studied with the standard pseudoisochromatic plates part 2, Farnsworth-Munsell 100 hue (FM 100) test, Nagel anomaloscope, colour vision meter 712-anomaloscope, and Goldmann-Weekers adaptometer. The ages of the myopes ranged from 20 to 49 years, the visual acuity from 6/12 to 6/6, and the refractions from -6.0 to -20.0 D. All the colour vision tests and dark adaptation examination gave normal results. However, the error scores of the myopes in (blue) box III of the FM 100 test were significantly higher than those of the controls matched for age. In dark adaptation, the rod thresholds of the myopes were significantly higher than in the controls. The stretching of the posterior pole of the eye might explain this minimal impairment of the photoreceptor layer of the retina without any visible degenerative changes in the fundus.