Bilberry extract concentrates anthocyanins from Vaccinium myrtillus. Each dose supplies a steady amount of these compounds, unlike whole fruit. The anthocyanins promote dark adaptation and blood flow in the retina.
People take it for visual function, night vision, and microvascular health. Some use it to ease eye strain from screens, though the historical evidence is modest.
A typical dose is 80-160 mg twice daily when using an extract standardized to 25% anthocyanins. Taking it with a meal can improve tolerance and absorption.
Bilberry may thin the blood mildly and lower blood sugar. Use caution with anticoagulant or diabetes medications. Pregnant or nursing women should consult a healthcare provider. Mild digestive upset is possible.