Purkinje effect

As Purkinje effect ( afterJan Evangelista Purkinje ) the different perception of brightness for day and night colors is called. Is or V '( λ ) curve shown - It is based on the different spectral sensitivity of the photoreceptor cells ( photoreceptors ) in daylight and at night see how it in the V ( λ ). The day before all the pins are active at night, especially the rods.

Since the rods react particularly strongly to blue-green light with a wavelength of approximately 500 nm, the sensitivity of the human retina moves in the dark in this direction. Therefore, in older submarines are used for example red light for interior lighting, if night observations were provided. Because at the red light sticks are little stressed and the eye is better adapted for seeing in the dark ( dark adaptation ). So at night it was possible to look through the periscope of the submarine, without the eyes had to adjust to the darkness outside the boat a long time.