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).
It is sometimes applied directly to the inside of the mouth for mild mouth and throat soreness.
Bilberry contains chemicals called tannins that can help improve diarrhea, as well as mouth and throat irritation, by reducing swelling (inflammation). There is some evidence that the chemicals found in bilberry leaves can help lower blood sugar and cholesterol levels. Some researchers think that chemicals called flavonoids in bilberry leaf might also improve circulation in people with diabetes. Circulation problems can harm the retina of the eye