Bilberry is used for improving eyesight, including night vision. In fact, during World War II, British pilots in the Royal Air Force ate bilberry jam to improve their night vision, but later research showed it probably didn’t help. Bilberry is also used for treating eye conditions such as cataracts and disorders of the retina. There is some evidence that bilberry may help retinal disorders. Some people use bilberry for conditions of the heart and blood vessels including hardening of the arteries (atherosclerosis), varicose veins, decreased blood flow in the veins, and chest pain. Bilberry is also used for chronic fatigue syndrome (CFS), hemorrhoids, diabetes, osteoarthritis, gout, skin infections, gastrointestinal (GI) disorders, kidney disease, and urinary tract infections (UTIs).