Most of us have heard it at some point: “Eat your carrots — they’ll help you see in the dark.”
It is one of those wonderfully persistent food facts that is not completely wrong, but is also nowhere near as magical as it sounds. Carrots can support normal vision as part of a healthy diet, but they will not give you night vision, turn you into a cat or help you read a book in a blackout.
So where did the carrot story come from?
The modern version of the myth became especially popular during the Second World War.
Britain was using increasingly effective radar systems to help detect enemy aircraft, including at night. At the same time, the public was encouraged to eat carrots, which were widely available and useful during wartime rationing.
Stories circulated suggesting that Royal Air Force pilots were so successful at spotting enemy aircraft in the dark because they ate plenty of carrots. The real explanation was rather more technological: radar was doing much of the hard work.
Whether the story was deliberately designed to fool the enemy, or simply became a convenient piece of wartime publicity, is still debated. What is clear is that the message stuck. Carrots became linked with extraordinary night vision in the public imagination — and they have been carrying that reputation ever since.
Why are carrots linked with eyesight at all?
Carrots are rich in beta-carotene, the orange pigment that gives them their colour.
Your body can convert beta-carotene into vitamin A. Vitamin A is important for several normal functions in the body, including the immune system, healthy skin and vision.
Within the eye, vitamin A is needed to help form rhodopsin, a light-sensitive protein in the retina. Rhodopsin plays an important part in helping the eyes respond to low levels of light.
So there is a genuine scientific link between vitamin A and seeing in dim conditions. That is the small kernel of truth inside the much larger carrot myth.
Can eating carrots improve night vision?
Only if poor night vision is related to vitamin A deficiency.
A shortage of vitamin A can affect the eye’s ability to adapt to darkness and may cause night blindness. In that situation, restoring an adequate vitamin A intake can help correct the deficiency.
However, if you already get enough vitamin A from a varied diet, eating extra carrots will not keep upgrading your eyesight. There is no hidden “night vision level” to unlock by finishing a second bag.
Think of vitamin A rather like an essential ingredient. Your eyes need enough of it to work normally, but more than enough does not turn normal vision into superhuman vision.
Do carrots help daytime vision?
Carrots can contribute to the nutrients needed for normal eye function, but they do not sharpen an existing spectacle prescription or remove the need for glasses.
If someone is short-sighted or long-sighted, or has astigmatism, eating more carrots will not alter the shape or focusing power of the eye. They may be good for dinner, but they are not a substitute for the correct lenses.
They also cannot prevent every age-related or medical eye condition. Good eye health depends on many things, including genetics, general health, smoking, sun protection, diet and regular eye examinations.
Carrots are not the only source of vitamin A
Carrots have excellent publicity, but they do not have a monopoly on vitamin A.
Beta-carotene is also found in foods such as sweet potatoes, spinach, red peppers, broccoli, mangoes and apricots. Preformed vitamin A is found in foods including eggs, dairy products, oily fish and liver.
For most people, a varied and balanced diet provides enough vitamin A without the need for supplements.
Should I take a vitamin A supplement for my eyes?
Not routinely. Vitamin A is fat-soluble, which means the body can store it, and too much preformed vitamin A can be harmful.
High-dose beta-carotene supplements are also not suitable for everyone. In particular, they have been linked with an increased risk of lung cancer in people who smoke or who have had heavy occupational exposure to asbestos.
Food is generally the sensible place to start. Anyone considering supplements because of a health concern should discuss it with an appropriate healthcare professional rather than assuming that more must be better.
What if I genuinely struggle to see at night?
Difficulty seeing in dim light can have many possible causes. These include an uncorrected prescription, cataracts, certain retinal conditions and other eye-health problems. Vitamin A deficiency is only one possibility and is uncommon in people eating a balanced diet in the UK.
If your night vision has noticeably worsened, driving after dark has become more difficult, or you are taking much longer to adjust when moving from a bright place into darkness, it is worth mentioning this at an eye examination.
The verdict
Carrots support normal vision because they contain beta-carotene, which the body can convert into vitamin A.
They may help if someone is genuinely deficient in vitamin A. But for most people, extra carrots will not improve night vision beyond normal, remove the need for glasses or provide the eyesight of an RAF night-fighter pilot.
So enjoy your carrots. They are nutritious, versatile and very good with a Sunday roast. Just do not expect them to replace headlights.
Carrots and eyesight: quick questions
Do carrots improve night vision?
Carrots can help support normal low-light vision because they contain beta-carotene, which the body can convert into vitamin A. But eating extra carrots will not improve night vision beyond normal if you already get enough vitamin A.
Can carrots improve your eyesight?
They contribute useful nutrients, but they cannot correct short-sightedness, long-sightedness or astigmatism, and they do not replace the need for appropriate glasses or contact lenses.
Which vitamin is important for seeing in dim light?
Vitamin A is needed to form rhodopsin, a light-sensitive protein used by the retina. A genuine vitamin A deficiency can affect dark adaptation and cause night blindness.
Why were RAF pilots associated with carrots?
During the Second World War, publicity linked British pilots’ night-time success with eating carrots. Radar technology was the more important explanation, but the carrot story proved much easier to remember.
Concerned about your night vision?
If you have noticed a change in your vision, are finding driving after dark more difficult or are due an eye examination, contact Actons Opticians for advice.
This article is for general information only and does not replace individual dietary, medical or eyecare advice.
Sources and further reading: NHS: Vitamin A; US National Institutes of Health: Vitamin A and carotenoids; Imperial War Museums: How radar changed the Second World War; Smithsonian Magazine: the wartime carrot myth.
