However, they complained that poor night vision hampered their missions. Fortunately, so the story goes, an herbalist suggested using bilberry preserve to enhance night vision. The pilots started eating bilberry jam every morning, and their night vision improved. From that point on, researchers turned their attention to bilberry, attempting to find out why bilberry improved night vision. Components Chemical analysis of bilberry shows the presence of tannins and flavonoids.
Tannins are probably responsible for bilberry's effect on diarrhea and wound healing.
These compounds are believed to be the key to bilberry's antioxidant effect. In a normal living cell, they are formed when a chemical reaction is not completed. Antioxidants capture the free radicals, thereby stopping the chain reaction and preventing further damage to living cells. Improving vision Bilberry has been shown to improve night vision by stimulating the production of rhodopsin, also called eye purple, in the retina. Some people's night vision improved dramatically just 20 minutes after they took bilberry.