Does Bilberry Extract Improve Night Vision in Pilots?

February 25, 2015

BLUF:  Bilberry is probably not effective in improving night vision visual acuity or contrast recognition.


It recently was brought to my attention that some pilots have added bilberry to their diets and others have been willing to shell out cold hard cash on bilberry extracts or leaves in pill form.  Why? For improved night vision.  The practice of ingesting bilberry to improve night vision dates back to its use by Royal Air Force (RAF) pilots in WWII.Is Bilberry effective in delivering on these claims the product often advertises?Well, like most things the research is not straightforward.  First, a look at the characteristics of Bilberry from the 'Natural Medicines Comprehensive Database':


Bilberry is a plant. The dried, ripe fruit and leaves are used to make medicine.Bilberry is used for improving eyesight, including night vision. In fact, during World War II, British pilots in the Royal Air Force ate bilberry jam to improve their night vision, but later research showed it probably didn’t help. Bilberry is also used for treating eye conditions such as cataracts and disorders of the retina. There is some evidence that bilberry may help retinal disorders.Some people use bilberry for conditions of the heart and blood vessels including hardening of the arteries (atherosclerosis), varicose veins, decreased blood flow in the veins, and chest pain.


A double-blinded, randomized placebo-controlled study from 2000 published in the Alternative Medicine Review found that there was no improvement in night vision in XX young males taking bilberry extract when compared to those taking placebo.

Possibly Effective for...

  • Circulation problems (chronic venous insufficiency). Early research suggests that taking bilberry extract that contains 173 mg of certain chemicals, called anthocyanins, daily for 30 days reduces symptoms associated with a circulation problem called chronic venous insufficiency (CVI). Other research suggests that taking 100-480 mg of bilberry anthocyanins daily for up to 6 months might improve swelling, pain, bruising, and burning associated with CVI.
  • Problems with the retina of the eye in people with diabetes or high blood pressure (retinopathy). Eating bilberry fruit containing a high amount of a certain chemical, called anthocyanoside, seems to improve retina problems associated with diabetes or high blood pressure.

Possibly Ineffective for...

  • Improving night vision. There is contradictory evidence about the effectiveness of bilberry for improving night vision. However, most evidence to date suggests that bilberry is not effective for improving night vision.


The dried, ripe fruit of bilberry is LIKELY SAFE for most people when eaten in typical food amounts.Bilberry fruit extracts are POSSIBLY SAFE when taken by mouth for medicinal uses for up to one year. Also, a specific combination product (Mirtogenol) containing bilberry and French maritime pine bark (Pycnogenol) has been used safely for up to 6 months.Bilberry leaf is POSSIBLY UNSAFE for most people when taken in high doses or for a long time.

Special Precautions & Warnings:

  • Pregnancy or breast-feeding: Not enough is known about the use of bilberry during pregnancy and breast-feeding. Stay on the safe side and avoid use.Diabetes. Bilberry leaf might lower blood sugar. Taking bilberry leaves along with diabetes medications might cause your blood sugar to go too low. Monitor your blood sugar closely.Surgery: Bilberry might affect blood glucose levels. This could interfere with blood sugar control during and after surgery. Stop taking bilberry at least two weeks before a scheduled surgery.


Bilberry Extract in Capsule
Bilberry Extract in Capsule

Although Bilberry has a fairly good safety track record, the best studies performed have not been able to find any true effect on improved night vision.  Therefore, it is unlikely to provide the desired result if used by aviators.  If you still want to use this supplement, I would recommend adding bilberry to your diet as a food source as the extract and leaves have a higher likelihood of causing interactions with medications, lowering your blood sugar or being combined with other unwanted ingredients by the manufacturer!


  1. Eric R. Muth, John M. Laurent.  The Effect of Bilberry Nutritional Supplementation on Night Visual Acuity and Contrast Sensitivity.  Alternative Medicine Review. Volume 5, Number 2.  2000.  
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