... Bilberry grows in North America, Europe, and northern Asia. What It Is Used For:Historically, bilberry fruit was used to treat diarrhea ... , scurvy, and other conditions.Today, the fruit is used to treat diarrhea, menstrual cramps, eye problems, varicose ... to the heart), and other circulatory problems.·Bilberry leaf is used for entirely different conditions, including diabetes. How It ...