Bilberry extracts have been extensively tested in the sixties on different conditions of impairment of visual functions.
The extracts alone or in association with b-carotene and vitamin E, administered to healthy subjects or to patients with visual disorders, induced in a high number of subjects a significant improvement in night vision, a quicker adaptation to darkness and faster restoration of visual acuity following exposure to a flash of bright light^(1-5).
Trials performed on air-traffic controllers, air pilots, car and truck drivers showed that anthocyanins-containing extract was able to improve the night vision and the adjustment to darkness^(6-8).
Later on, Forte et al.⁽⁹⁾ confirmed the results obtained in the above reported studies.

Recently Canter and Ernst⁽¹⁰⁾ published a critical review of the clinical studies (1964-2001) concerning the activity of the V. myrtillus extracts on human vision under reduced light condition.
Thirty trials have been retrieved, of these 12 were placebo-controlled. Of these 5 were randomized controlled trials and 7 were placebo-controlled non randomized trials. The 4 most recent trials were all randomized controlled trials (RCTs) with a negative outcome. A fifth and 7 non randomized controlled studies reported positive effects on outcome measures relevant to night vision. Nevertheless the fifth RCT and 7 placebo-controlled, but non randomized trials, all report positive effects on at least one outcome measure relating to vision in reduced light.
The negative results however are confounded by several factors: different products, i.e. different phytochemical composition have been used in the trials; the anthocyanins amount administered varies between trials and the trials with a negative outcome corresponds to the lowest doses utilized (36, 40, 48 and 120 mg anthocyanosides); the enrollment criteria.
As for the effects of bilberry extract on night vision the available data has not allowed to draw a definite conclusion.

1. Jayle G.-E, Aubert L., Thérapie 19, 171 (1964).
2. Jayle G.E., Aubry M., Gavini H., Braccini G., de la Baume C., Ann. Ocul. 198, 556 (1965).
3. Fiorini G., Biancacci A., Graziano F.M., Ann. Ottal. Clin. Ocul. 6, 371 (1965).
4. Urso G., Ann. Ottal. Clin. Ocul. 93, 931 (1967).
5. Zavarise G., Ann. Ottal. Clin. Ocul. 94, 209 (1968).
6. Belleoud L., Leluan D., Boyer Y., Rev. Méd. Aéro. Spat. 5, 45 (1966).
7. Belleoud L., Leluan D., Boyer Y., Rev. Méd. Aéro. Spat. 6, 5 (1967).
8. Rouher F., Sole P., Ann. Med. Accidents Traffic, 3-4 (1965). 
9. Forte R., Gazzaniga D., Iacobelli L., Tassone R., Rispoli M., Ann. Ottal. Clin. Ocul. 122, 325 (1996). 
10. Canter P.H., Ernst E., "Anthocyanosides of Vaccinium myrtillus (bilberry) for night vision--a systematic review of placebo-controlled trials.", Surv. Ophthalmol. 49, 38 (2004).

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