Small studies have suggested bilberry may be helpful in preventing macular degeneration occurrence or progression. It has not, however, been the focus of a randomized, controlled trial (the type of trial that is most helpful and objective in determining a new treatment’s efficacy).
A theory exists regarding bilberry’s positive effect on night vision, as allegedly proven when it was used by Britain’s Royal Air Force pilots during World War II. This finding has not been corroborated in sub-sequent studies.
Blueberries are also believed to have antioxidant properties and may also be of benefit in preventing or slowing macular degeneration. However, blueberries, like bilberries, have not been evaluated in randomized clinical trials. This lack of study does not mean that either blueberries or bilberries are not beneficial, but simply that they have not been subjected to the same scrutiny as AREDS supplements; therefore we cannot make definitive recommendations.
Without such evidence, it seems reasonable to suggest that one’s diet be rich in such foods, but the administration of supplements without more data carries potential risks.