The carrot thing was cover. It's true that lack of vitamin A can adversely affect your eyesight, and carrots have vitamin A, but taking lots more than the minimum doesn't make your eyesight *better*.
The British were shooting down a lot of attacking German planes during WWII, thanks to RADAR detecting and locating the bombers. So that the Germans didn't bomb the RADAR antenna sites, the British downplayed the importance of RADAR and made it seem like their fighter pilots had superior eyesight / night vision.
Vitamin A is accurate and yes we need more, but the carrots actually ARE healthy and can be used as a critical component still. I’m a certified pro in that exact field and study that exact thing: carrots have abundant beta-carotene and lutein which are two very strong vitamin components needed for our eye health. This was tested in a study done for the AREDS 1 and 2 formulas (primarily for macular health). At the ends of those periods of time on the vitamins (primarily containing lutein and zeaxanthine) patients had an increase in mass and more regular looking macula and fovea. “More regular” not “fixed” mind you. MacuHealth sells this formula and offers their study notes on their website. I take those OCT scans daily! It’s very interesting to look deep into the windows of someone’s soul. I look at the retina “film” of your brain’s eye “camera.”
The British were shooting down a lot of attacking German planes during WWII, thanks to RADAR detecting and locating the bombers. So that the Germans didn't bomb the RADAR antenna sites, the British downplayed the importance of RADAR and made it seem like their fighter pilots had superior eyesight / night vision.