Purkinje effect

Tendency for sight to shift toward blue colors at low light levels

The Purkinje effect or Purkinje phenomenon, sometimes called the Purkinje shift (often pronounced), is the tendency for the peak luminance sensitivity of the eye to shift toward the blue end of the color spectrum at low illumination levels as part of dark adaptation. In consequence, reds will appear darker relative to other colors as light levels decrease. The effect is named after the Czech anatomist Jan Evangelista Purkyně (Czech: [ˈpurkɪɲɛ]).

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