Bilberry has long been a remedy for poor vision and \"night blindness.\" Clinical tests confirm that given orally it improves visual accuracy in healthy people, and can help those with eye diseases such as pigmentosa, retinitis, glaucoma, and myopia. During World War II, British Royal Air Force pilots ate Bilberry preserves before night missions as an aid to night vision. Bilberry works by improving the microcirculation and regeneration of retinal purple, a substance required for good eyesight.