World War II

During World War II, German bombers were conducting nighttime raids on British cities. To help meet the threat, British scientists invented an airborne radar system that allowed British fighter planes to find German bombers in the dark. With the help of this highly effective radar system, British fighters began shooting down the German bombers and turning the tide in the Battle of Britain. The radar system was top-secret, and it was important to the British that the Germans not discover they had it. How then to explain the sudden success in nighttime aerial combat? As a ruse, the British government began to claim that their pilots were able to see better at night after eating lots of carrots. They even produced posters such as these, to bolster the claim that carrots were giving their soldiers, pilots, and civilians better night vision.

Even though it was intended only as a fake-out, the British population didn’t know that. Eating your veggies is good for eye health generally and a vitamin A deficiency can cause a diminution of night vision. But eating lots of carrots does not enable a person to see in the dark and will not improve the vision of someone with already healthy eyesight. Nevertheless, the idea that carrots improve vision went into popular culture, where it remains to this day.