According to an article published  in Smithsonian Magazine written by  

K. Annabelle Smith, the widely believed  notion that eating carrots enhances night  

vision is largely a myth popularized by a  British World War II propaganda campaign.

Although carrots are rich in Vitamin A, which  is essential for eye health, and a study from  

Johns Hopkins in 1998 indicated that vitamin  A supplements could reverse poor vision in  

those with a deficiency, the vegetable's  abilities have been notably exaggerated.

During WWII, the British government  spread the belief that carrots could  

help people see in the dark  as a misdirection tactic.

The Royal Air Force (RAF) had developed a new  radar technology, the Airborne Interception  

Radar (AI), which allowed them to locate enemy  bombers before they reached the English Channel.

To keep this technology secret and perhaps  mislead German forces, the Ministry of Information  

promulgated the idea that RAF pilots, like John  Cunningham who was known for his exceptional  

night-flying abilities, were consuming large  amounts of carrots to enhance their night vision.

This idea was so widely publicized that  not only did it infiltrate public belief  

during the wartime period, but  it also lingered long afterward,  

developing into the common belief that  carrots are a sort of superfood for eyesight.

While it's true that a lack of Vitamin A (which  carrots are rich in) can lead to impaired night  

vision, the narrative that excess consumption  could provide almost superhuman abilities to see  

in the dark was a clever exaggeration utilized  for strategic misdirection during the war.

During this time, with resources like  sugar and other food items becoming  

scarce due to German blockades,  the British government encouraged  

citizens to be self-sustaining and to  consume surplus vegetables like carrots.

Campaigns and characters like "Dr.  Carrot" and "Potato Pete" were introduced,  

advocating for the consumption of these  vegetables and spreading alternative  

recipes utilizing them as sugar  substitutes in a variety of dishes.

Although this myth of carrots improving night  vision is still widely believed today, it is  

essential to recognize its origin as a tool of  wartime propaganda and not as a scientific fact.

While carrots do play a role in maintaining  eye health due to their Vitamin A content,  

their supposed night-vision superpowers were an  exaggeration meant to protect a military secret.