Quote:
Originally Posted by JohnCarterOfMars
I don't know if it's historical or not, but astronomers knew for a long time that red lights reduce the effect of light on "night vision" that a white light would do. Red lights are used to read star maps and readings on instruments without causing the pupils to close. It keeps people dark adapted. Could this be why red lights were used in conning towers, so they wouldn't lose night vision when going onto the bridge?
|
U-boat watch crewmen usually wore rubber goggles fitted with red glass lenses (as seen in the 1981 Das Boot movie) to help adjust their eyes to low light levels at night. Hence there was no significant need for a red light as well - and not much evidence for it even in conning towers (possibly an early war thing that became obsolete).