The famous story is that bilberry sharpened the night vision of wartime fighter pilots.
That was propaganda, and the real evidence for your eyes is far smaller and quieter.

The bilberry, Vaccinium myrtillus, is the small, dark, wild cousin of the blueberry, carpeting the forest floors of Sweden and the Nordic countries, where it is gathered by the bucketful every late summer. Smaller and far more intensely colored than any cultivated blueberry, it stains the fingers and the tongue a deep, staining blue-purple.

In Sweden it is everyday food, cooked into the soup blåbärssoppa, spooned over porridge, and long valued as a folk remedy for everything from an upset stomach to tired, sore eyes. That last use, for the eyes, is the one that made it globally famous, thanks to a single, famous wartime story.

During the Second World War, British airmen were said to eat bilberry jam to sharpen their night vision for dark missions, and one ace pilot became the smiling poster boy for it. The tale spread far and wide, and the idea that bilberry is good for your eyesight has never really left us since, right up to today.

There was, it turns out, a very particular reason that story was allowed to circulate so freely at the time. It was almost certainly a lie, and a deliberate, strategic one at that.

The night-vision story was pure wartime propaganda. The British spread it to explain how their pilots could suddenly find targets in the dark, hiding the real secret, a new airborne radar, behind a wholesome tale about berries, and the trials ever since have mostly failed to find any real effect of bilberry on night vision at all in healthy eyes.

What the berry does genuinely have is a heavy load of anthocyanins, the deep pigments that make it so dark, which are real antioxidants and seem to support the tiny blood vessels that feed the tissues, including those in the eye. On that footing, small studies hint at modest help for tired, strained eyes and for retinal circulation, though the evidence stays thin and falls far short of the old legend.

The night-vision tale was wartime cover for radar, not a fact about berries.

So the honest verdict is a nutritious antioxidant berry with a modest, real role for eye fatigue and small blood vessels, not the vision-sharpener of myth. It is a pleasant, low-risk thing to eat or take, but it will not fix failing eyesight, and any genuine change in your vision belongs with an eye doctor, not a supplement bottle on the shelf.

The how-to

Enjoy it as a nutritious berry with a modest eye benefit, and drop the night-vision expectation entirely.

Fresh or frozen wild bilberries are ideal where you can get them, deep purple all the way through, unlike a pale-fleshed cultivated blueberry, while a standardized bilberry extract stating its anthocyanin content is the form used in the eye-fatigue studies. Ordinary blueberries are a fine, if milder, substitute.
For a real dose of anthocyanins, the studies used standardized extracts, often a few hundred milligrams a day, rather than a token spoon of jam. Eating the berries regularly is pleasant and healthy, and the extract is what to reach for if you specifically want the eye-fatigue effect.
At most, expect a little less eye strain after long screen days and some support for small blood vessels, not sharper night vision and not a cure for any eye disease. Treat it as a nice addition, not a treatment.
Bilberry is very safe as a food. The concentrated extract may mildly thin the blood and nudge blood sugar, so mention it if you take a blood thinner or diabetes medication, and remember that any real change in your vision, new floaters, blurring, or loss of sight, needs an eye doctor promptly, not a berry.

Tomorrow: Italy and artichoke
the bitter leaf with real trials for digestion and cholesterol, hiding in a favorite vegetable.

See you then.