We and others have demonstrated that provision of n-3 long chain polyunsaturated fatty acids (n-3 LCPs) in preterm and term babies is associated with retinal electrical responses to light stimuli, and to brain cortex related visual acuity maturation, that are similar to those observed in human milk fed infants. Our follow up results in young children suggest that neurodevelopment and cognitive abilities are also enhanced by early provision of n-3 LCPs through breast milk or DHA-fortified foods. Breast fed infants also require n-3 LCPs after weaning to achieve optimal visual acuity at 12 months of age. Good quality evidence supporting a role for n-3 LCP consumption to enhance learning and/or behaviour in school-age children is currently lacking. Evidence supporting the potential importance of n-3 LCP consumption for good cognitive health in older age is now beginning to emerge. Recent cross-sectional surveys have reported that higher fatty fish/n-3 LCP consumption and or higher n-3 LCP blood concentrations are associated with reduced risk of impaired cognitive function. Similarly, prospective cohort studies have shown that increased fish consumption and higher n-3 LCPs in blood lipid sub-fractions are associated with decreased risk of dementia in older people. We are presently conducting a large randomised controlled trial in a group of adults aged 70-79 years to assess whether an n-3 LCP supplement will preserve retinal function and prevent age related cognitive decline.