Is It Legit?
Partially Supported
“Blueberries improve sight”
Educational, not medical advice. Always consult a qualified healthcare provider before changing your diet, supplements, or routine. Full disclaimer.
What the science says
Blueberries do not sharpen general sight or improve night vision, but bilberry (a close relative) and blueberry compounds may modestly ease eye fatigue and help vision recover faster after a bright flash of light. Across 8 studies with a low evidence score of 2 out of 5, the strongest trials found no benefit for night vision, and the positive results are narrow, mostly involving bilberry or multi-ingredient extracts rather than blueberries alone. Eating blueberries as food is unlikely to meaningfully change your eyesight day to day.
Full analysis
The evidence is a mix of small placebo-controlled trials and systematic reviews, mostly testing bilberry extract (a close relative of blueberry) or blueberry anthocyanins - the purple-red plant pigments thought to be behind these effects - against a dummy pill.
Two small trials found narrow benefits: bilberry extract eased some eye-fatigue symptoms in computer workers, and blueberry anthocyanins helped vision recover faster after a bright flash of light, though neither improved night vision itself. A systematic review of bilberry and night vision found no benefit, and noted that the more rigorously a trial was designed, the weaker the results.
None of this applies to whole blueberries eaten as food rather than concentrated extracts, and most trials are small and short. With an evidence score of 2 out of 5 across 8 studies, this is thin, mixed evidence rather than a settled finding.
The practical takeaway: there is little reason to expect blueberries to meaningfully improve your eyesight, though concentrated bilberry extract may modestly ease digital eye fatigue.
Key studies
The 3 studies that carry the verdict, out of 8 reviewed.
[1]Blueberry effects on dark vision and recovery after photobleaching: placebo-controlled crossover studies.
Kalt W et al. · Journal of agricultural and food chemistry · 2014
In placebo-controlled trials, blueberry compounds did not help people see better in the dark or adjust faster to night vision, but they did help vision bounce back faster after a bright flash of light temporarily blinded participants.
View paper[2]Bilberry extract supplementation for preventing eye fatigue in video display terminal workers.
Ozawa Y et al. · The journal of nutrition, health & aging · 2015
In computer workers, taking bilberry extract, a close relative of blueberry, eased some measured and self-reported symptoms of eye fatigue from screen use.
View paper[3]Anthocyanosides of Vaccinium myrtillus (bilberry) for night vision--a systematic review of placebo-controlled trials.
Canter PH et al. · Survey of ophthalmology · 2004
This review of placebo-controlled trials found no support for bilberry compounds improving normal night vision, and the more carefully designed a trial was, the less likely it was to find any benefit.
View paper