Bilberry, Vaccinium myrtillus, has been shown to improve night vision and help heal eye irritations. They contain anthocyanidins, which protect collagen structures in the eyes, thereby preventing and treating macular degeneration and retinopathy. Bilberries tone blood vessels and improve circulation. Studies suggest that the antioxidants in bilberries can protect against diseases of the circulatory system. Blueberry is a cousin of bilberry and can be used interchangeably. Blueberries and bilberries can improve atherosclerosis and varicose veins.
No known warnings for the fruit; long-term use of the leaves can potentially cause gastric irritation and kidney damage, but they have a history of safe use.