Bilberry contains anthocyanosides which are potent antioxidants which strengthen blood vessels and capillary walls, improve red blood cells, stabilize collagen tissues such as tendons, ligaments and cartilage and has cholesterol lowering effects. They also increase retinal pigments that allow the eye to tolerate light. In addition, it helps to maintain the flexibility of red blood cells, allowing them to pass through the capillaries and supply oxygen. The herb has been shown to be a vasodilator that opens blood vessels and lowers blood pressure. Since the eyes have a high concentration of capillaries, bilberry may be particularly helpful in improving eyesight. The herb has been shown to improve night vision, slow macular degeneration, prevent cataracts and diabetic retinopathy. Scientific studies have shown improvement in the eyesight, circulation, angina, stroke and atherosclerosis. It is also used to improve varicose veins and has anti-aging effects on collagen structures.