Cold-water fish like salmon, sardines, herring, mackerel and albacore tuna are the best fish to eat for the health of the back of the eye. DHA (docosahexaenoic acid) is the primary omega-3 fatty acid found in these fish. It's a nutrient that concentrates in the retina and may prevent plaque — which causes macular degeneration — from forming there. Boosting your DHA by eating four 3.5- to 4-ounce servings of cold-water fish weekly is a wonderful way to help prevent eye disease, Pratt says.
Indeed, a Johns Hopkins study published in the journal Ophthalmology in December reported that eating fish and shellfish that are rich in omega-3 seems to protect against advanced-age-related macular degeneration, even in those who smoked or were overweight — both risk factors for the disease. Cold-water fish also may help prevent retinopathy — damage to the retina — including blindness caused by complications from diabetes.