Tea made from blueberry leaf (Vaccinium) has been used for diabetes when insulin is not being used because it can reduce blood sugar. It also cleanses the urinary tract, and has general astringent properties. It has been used for diarrhea as well.

This tea nutritionally provides oleanolic acid, ursolic acid, beta-amyrin, fatty acids, sugars, and tannins.

Bilberry (Vaccinium myrtillus) is most well-known for its use in improving vision. Bilberry can be helpful for both night vision and helping with retinal deterioration.

Nutritionally, bilberry provides manganese and tannins. It has a slight diuretic effect, and a slight antiseptic effect. Besides improving sight, it also helps to improve circulation and strengthen blood vessels.