Ever heard of the saying: Eating carrots will improve your vision? Well, if you subscribe to that mantra, then here's some bad news: It's a LIE.

The good news? It helped the Allies defeat the Nazis. Say what?

Carrots have a lot of Vitamin A, and eating lots does promote good eye health. But pumping yourself with Vitamin A isn't going to give you 20/20 vision.

Smithsonian Magazine reports the theory of John Stolarczyk, a curate of the World Carrot Museum. According to him, the myth began during World War II, when Nazies were bombing London. Then later, out of no where, the British Royal Air Force started shooting down more Nazi planes. They had the help of a new radar that the RAF did not want anyone to know about. So they had to advertise something else.
The Royal Air Force were able to repel the German fighters in part because of the development of a new, secret radar technology. The on-board Airborne Interception Radar (AI), first used by the RAF in 1939, had the ability to pinpoint enemy bombers before they reached the English Channel. But to keep that under wraps, according to Stolarczyk’s research pulled from the files of the Imperial War Museum, the Mass Observation Archive, and the UK National Archives, the Ministry provided another reason for their success: carrots.
Yup, carrots. [Smithsonian]