If any two ingredients anchor the modern eye-supplement category, it's lutein and zeaxanthin. Both are carotenoids that accumulate specifically in the macula, the part of the retina responsible for sharp, central vision, where they're believed to filter high-energy blue light and provide localized antioxidant protection.
The National Eye Institute's AREDS2 trial remains the single most credible large-scale study in this space: 4,203 participants aged 50–85 at risk of advanced age-related macular degeneration (AMD) were randomized to test adding lutein/zeaxanthin and omega-3 fatty acids to the original AREDS formula [1]. A follow-up analysis found that replacing beta-carotene with lutein/zeaxanthin reduced progression to advanced AMD by about 18–20%, with the added benefit of not increasing lung cancer risk in smokers the way beta-carotene did [2][3].
The AREDS2 formulation used 10mg lutein and 2mg zeaxanthin daily. Many general multivitamins include far smaller amounts — sometimes negligible — which is a common criticism of basic eye vitamins compared to purpose-built formulas. See our guide to reading supplement labels for how to check this yourself.