Why is red light used on submarines?

Why is red light used on submarines?

Red light, night light.

Asked by: John Awbery, Reading

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The human eye is less sensitive to longer wavelengths, so red light is chosen to preserve the night vision of the crew while still allowing them to still see their instrument panels. Submarines switch to red light when it’s dark outside and crew members need to use the periscope or go on watch duty.


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