Vitamin B2 (Riboflavin) for Eye Health

Research suggests that riboflavin (vitamin B2) plays several distinct roles in eye health, with the strongest and most consistent evidence coming from its use in corneal cross-linking (CXL), a clinical procedure in which riboflavin drops are activated by ultraviolet-A light to chemically stiffen corneal tissue and halt the progression of keratoconus and related conditions. Multiple reviews spanning 2022 to 2026 consistently support CXL's effectiveness for this purpose, and a 2024 randomized controlled trial found that real-time monitoring of riboflavin concentration during the procedure could predict treatment outcomes with high accuracy, pointing toward more personalized approaches. Beyond CXL, a large population-based study of nearly 3,000 adults found that long-term riboflavin supplementation was associated with lower prevalence of certain types of age-related cataract, though as a cross-sectional study it cannot confirm a direct cause-and-effect relationship, and experimental mouse research suggests that riboflavin deficiency during early development may cause cone photoreceptor loss in the retina that is only partially reversible with supplementation. The evidence base is encouraging but uneven — dominated by reviews and experimental studies rather than large human clinical trials focused specifically on riboflavin supplementation — and one 2012 review raises the nuance that riboflavin can itself act as a photosensitizer when activated by light, meaning that protective nutrients in the diet may also play a role in managing riboflavin-related oxidative activity in eye tissue.