Research Sources
Where our health facts, trial context, and product details come from.
Reviewed October 2, 2026
Primary health sources we prioritize
For medical and nutrition context, we favor U.S. government health agencies and peer-reviewed research. We use manufacturer pages for current product facts such as ingredient lists, directions, pricing and certification claims, not as independent proof of effectiveness.
- National Eye Institute — AREDS/AREDS2 FAQ
- National Eye Institute — Nutritional Supplements for AMD
- NIH Office of Dietary Supplements — Vitamin A
- NIH Office of Dietary Supplements — Zinc
- PubMed — Bilberry extract trial in visual-display workers
- PubMed — Astaxanthin/lutein/zeaxanthin visual-display trial
- PubMed — Lutein/zeaxanthin visual-performance trial
Product sources checked for comparison pages
VisiVra seller pages, Bausch + Lomb PreserVision and Ocuvite pages, MacuHealth’s Triple Carotenoid Formula page, and EyePromise Restore’s product page were reviewed in October 2026. Competitor manufacturer pages are used only to describe their own published labels, positioning, directions or certification claims.
How we handle conflicts
If a seller claim conflicts with a higher-quality independent source, we describe the claim as a seller claim and rely on the stronger source for the health conclusion. If a dose is not disclosed, we say it is not disclosed rather than estimating it.
