Bilberry is any of several species of low-growing shrubs in the genus Vaccinium (family Ericaceae), bearing edible berries. The species most often referred to is Vaccinium myrtillus L., but there are several other closely related species. Bilberries are distinct from blueberries but closely related to them.
Often associated with improvement of night vision, bilberries are mentioned in a popular story of World War II RAF pilots consuming bilberry jam to sharpen vision for night missions. A study in 2000 by the U.S. Navy found no such effect and origins of the RAF story cannot be found. After the introduction of radar, RAF bombing became more accurately targeted, but to confuse the enemy, the story was leaked that it "was something in the pilots' diet" that improved their targeting - that something was carrots, not bilberries, and the story was concocted merely to keep the Germans from knowing the real reason for improved accuracy.
Although the effect of bilberry on night vision is unfounded, laboratory studies in rats have provided preliminary evidence that bilberry consumption may inhibit or reverse eye disorders such as macular degeneration.