Objective: To examine the associations between near and distant visual acuity and biomarkers of Hg, Pb, n-3 fatty acids and Se from the local diet of fish-eating communities of the Tapajós River in the Brazilian Amazon. Design: Visuo-ocular health and biomarkers of Hg (hair, whole blood, plasma), Pb (whole blood), Se (whole blood and plasma) and n-3 fatty acids (plasma total phospholipids) were assessed in a cross-sectional study. Setting: Lower Tapajós River Basin (State of Pará, Brazil), May to July 2006. Subjects: Two hundred and forty-three adults ($15 years) without diagnosed agerelated cataracts or ocular pathologies. Results: Near visual acuity was negatively associated with hair Hg and positively associated with %DHA, with a highly significant Log Hg 3 age interaction term. Stratifying for age showed that while young people presented good acuity, for those aged $40 years, clinical presbyopia was associated with hair Hg $ 15 mg/g (OR 5 3?93, 95 % CI 1?25, 14?18) and %DHA (OR 5 0?37, 95 % CI