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Dark adaptation

The adjustment of the eye occurring under reduced illumination in which the sensitivity to light is greatly increased or the light threshold is greatly reduced.

dark adaptation is slower than light adaptation. During dark adaptation rhodopsin is built up in the retinal rods. The process of adjusting the eyes to low levels of illumination; cones adapt first; rods continue to adapt for up to four hours.Due to dark prevailing as an external factor preventing normal vision, the eyes become more sensitive to light and therefore visualise the external environment more clearly, an adaptation to combat the blindness caused by the dark.