Millions of children have been encouraged to crunch carrots for the sake of their eyesight. But those promises of better vision, including the ability to see in the dark, exist mainly thanks to a wartime propaganda campaign.
During World War II, the British government attributed the ability of its night-flying pilots to shoot down Nazi bombers to their carrot intake. In reality, the pilots were employing a new type of radar. Although it was a ruse to throw Germans off track, the idea caught on. Even British civilians began eating more carrots in order to better find their way around during blackouts, and also planted them in "victory gardens" [source: Smith].
The myth of vision-improving carrots leapt continents and decades, and remains powerful today. While it's true that carrots are good for maintaining vision, they don't offer visual superpowers, like seeing in the dark. However, carrots are high in beta carotene, a component in vitamin A, which is essential for vision. In fact, if a person has a vitamin A deficiency, correcting it can improve poor night vision [source: O'Connor].