Marty Ottenheimer pointed out to me the other day that Carrots do not actually help vision. Rather, the story we often hear is a result of a rumor from WWII. ABC Science explains:
…if you don’t get enough carotenes or Vitamin A in your diet, eventually you will suffer problems in your vision. This was the basis of the myth started by the Royal Air Force, the RAF.
In the Battle of Britain, in 1940, the British fighter pilot, John Cunningham, became the first person to shoot down an enemy plane with the help of radar. In fact, in WW II, he was the RAF’s top-scoring night fighter pilot, with a total of 20 kills. Some pilots were better flying in daylight, while others, like Cunningham, were better at night. His nickname was “Cats’ Eyes”. The RAF put out the story in the British newspapers that he, and his fellow night pilots, owed their exceptional night vision to carrots. People believed this to the extent that they started growing and eating more carrots, so that they could better navigate at night during the blackouts that were compulsory during WW II.
But this story was a myth invented by the RAF to hide their use of radar, which was what really located the Luftwaffe bombers at night – not human carrot-assisted super-vision.
The punch-line is that German folklore already held that carrots would make eyes better. Susceptibility to fraud is usually rooted in pre-existing beliefs and prejudice.