Cod Liver Oil for Eye Health

Research suggests that cod liver oil and its key nutrients — particularly vitamin A and omega-3 fatty acids like DHA — have been studied in connection with several aspects of eye health, including vitamin A deficiency-related conditions, age-related lens changes, and retinal protection in neurodegenerative disease. The available evidence comes from a mix of historical reviews, population-based observational studies, animal studies, and public health literature rather than rigorous clinical trials in humans, which limits the strength of conclusions that can be drawn. Studies indicate that vitamin A, historically delivered in part through cod liver oil, plays a well-established role in the visual cycle and in preventing conditions like xerophthalmia and night blindness, particularly in populations with nutritional deficiencies, while a 1997 population-based study found that nutritional supplement use was associated with reduced likelihood of age-related lens opacities, though the specific contribution of cod liver oil could not be isolated. A 2025 mouse study found some retinal protective effects from DHA-rich oils, including cod liver oil, in an Alzheimer's disease model, though results were mixed depending on the specific outcome measured, and findings in animal models do not necessarily translate to humans.