By Karen L. Kier
Pharmacist on behalf of the Healthwise Team at Ohio Northern University

The idiom on target is best described as being on schedule or making good progress to achieve your goals or the results you wanted. During World War II, it was reported the British Royal Air Force pilots ate bilberry jam before engaging the enemy in dogfights at night. It has been folklore that bilberry improved their night vision and contributed to the success of their air to air combat with the Germans. 

Does science support the use of bilberry for improving vision?

Bilberry grows in northern Europe as well as northern Canada and the United States. It is a relative of the North American blueberry. They belong to the scientific family Ericaceae and the Vaccinium species. The bilberry is a perennial shrub with a dark purple-blue colored berry, which is coarsely wrinkled. 

Similar to the blueberry, the bilberry is rich in anthocyanins. The anthocyanins create the beautiful purple-blue color of these berries, which contributes to the strong antioxidant properties. When our body and cells are under stress, tissue can be damaged. The antioxidants can provide a means to help repair some of this damage. 

Due to the antioxidants in bilberry, the herbal product has been evaluated for managing diseases. Bilberry supplements have been researched for their potential to help with reducing cancer, inflammation, irritable bowel, and lower blood pressure. Based on the World War II stories, researchers have done studies looking at the effects of bilberry on the eyes. 

There are some questions on whether bilberry jam was actually consumed by the pilots and the story may have been created to distract the Germans from the work the British were doing on testing radar equipment on their planes. Other stories indicate the pilot success was based on carrots instead. Carrots also contain antioxidants, but different compounds. 

Besides the World War II stories, research has shown the anthocyanins found in bilberry and blueberries has a direct effect on the retina of the eye with properties to help with damaged cells. 

So, what does the research indicate?

The Naval Aerospace Research Laboratory located in Florida and the Tel Aviv University both did a research study giving young men either bilberry supplements or placebo to see if it helped with their vision. The amount of bilberry was similar to the amount one would consume in their diet. The results of the research showed no improvement in visual acuity or night vision. 

A study evaluating bilberry in open-angle glaucoma found improvements in contrast sensitivity and visual function. Glaucoma is an eye disease where the pressure builds up and leads to changes in vision and if uncontrolled can result in blindness. Glaucoma is easily detected with an eye exam and can be successfully treated with medications. However, in a survey of patients with glaucoma, over 50% took an eye supplement containing bilberry. 

Numerous studies have not shown a benefit of using bilberry alone to treat eye disorders. In the studies, the usual dose of bilberry is 160 to 240mg daily taken for at least six months to determine if there is a benefit. It is very important to work with your healthcare provider to find the best treatment options to prevent eye damage and blindness.

On the market, many eye supplements contain bilberry combined with other ingredients promoted for eye health. Most of these products contain various vitamins, minerals and natural products. Other ingredients can include maritime pine extract (pycnogenol), docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA), lutein, and other antioxidants. 

The combination products can have some benefits but should never be used alone to control an eye disease. Ask your pharmacist or eye health professional if they recommend these products.

Even though these supplements are natural products including bilberry, they can have some side effects including gastrointestinal problems such as bloating and gas. Deaths have been reported when bilberry fruit is combined with bilberry leaves at very high doses for prolonged periods of time. Doses exceeding 2 grams per day can be dangerous. 

The quality of eye supplements can vary by company and are not regulated by the Food and Drug Administration. A study of 11 bilberry extract supplements found 55% to be of good quality, while 45% were poor quality. Caution is advised when selecting supplements. 

Talk to your pharmacist about supplements to stay on target with your eye health!