During World War II, British posters claimed carrots improved night vision.

But the real reason behind getting people to eat more carrots was simpler: carrots were cheap and easy to grow during wartime food shortages. The “night vision” story also helped hide the fact that British pilots were using new radar technology during the Battle of Britain.

Carrots and leafy greens (like spinach and kale) contain beta-carotene, which your body turns into vitamin A. Vitamin A helps special cells (the rod and cone cells) in your retina to work properly so you can see colors, see in dim light, and notice things in your side (peripheral) vision.

Not getting enough vitamin A can harm your eyes or even cause blindness in extreme cases.

Most people in the United States already get enough vitamin A, so extra carrots won’t improve vision. Eating too many can even turn your skin orange - a harmless and reversible condition called carotenemia!