Our eyes may be small, but they are among the most metabolically active organs in the body. Every second they are converting light into signals, sending those signals to the brain, adjusting focus, and maintaining appropriate moisture levels. This constant work requires a high and continuous supply of nutrients.

The way we live today places greater demands on our vision. Long hours in front of screens, increased exposure to artificial lighting, and longer lifespans all add stress to the delicate tissues of the eye. This makes nutritional support for vision an increasingly important topic, not only in the context of ageing, but also for maintaining optimal function throughout life.

Antioxidants such as vitamin C and plant pigments like lutein are often associated with eye health, but fewer people realise that fats, specifically omega fatty acids, are just as essential. These unique fats are incorporated directly into the structure of the eye and play roles in everything from visual signalling to maintaining a stable eye moisture.  

For vision, the omega-3s of greatest importance are DHA (docosahexaenoic acid) and EPA (eicosapentaenoic acid).

DHA is a fundamental building block of the retina, especially concentrated in the photoreceptor outer segments, the light-sensing part of the eye. These outer segments are renewed roughly every ten days, which means the eye has a constant demand for DHA to rebuild them. DHA’s structure, with multiple double bonds, makes cell membranes more fluid. This fluidity is critical for phototransduction, the process by which light is turned into an electrical signal. Without enough DHA, the membranes of photoreceptor cells become less flexible, and signalling can become less efficient.

EPA, though less concentrated in the retina than DHA, serves an equally important role. It is a precursor to signalling molecules known as resolvins and protectins, which help regulate inflammatory responses in the eye. Since ocular tissues are highly sensitive to oxidative stress and inflammation, EPA helps create a more balanced environment, complementing DHA’s structural role.

Together, DHA and EPA form a partnership: DHA supports the architecture of vision, while EPA helps maintain the conditions in which that architecture can thrive.

Clear, comfortable vision depends on the eye’s ability to stay moist and protected. The surface of the eye is covered by a very thin layer of fluid that keeps it smooth, nourished, and free from irritation. When this layer breaks down too quickly, light scatters instead of entering the eye cleanly, which can lead to blurred or uncomfortable vision.

This protective coating is made up of three parts:

• Water, which keeps the eye hydrated.

• Mucus, which helps spread the water evenly across the surface.

• The lipid layer, which sits on top and slows down evaporation.

Omega-3 fatty acids are particularly important for the lipid layer. DHA and EPA appear to improve the quality of these secretions, making them less likely to become thick or blocked. A healthier lipid layer means moisture lasts longer, the eye surface stays comfortable, and vision remains clear.

This is especially relevant in everyday life, where long periods of screen use often mean fewer blinks and more strain on the eye’s protective coating. By supporting the lipid layer, omega-3s may help the eyes stay hydrated and comfortable even under demanding conditions. 

Food remains the most natural and effective way to supply the eye with omega fatty acids.

• Marine sources: Oily fish such as salmon, sardines, anchovies, herring, and mackerel are the richest sources of DHA and EPA. These should ideally be eaten two to three times per week.

• Shellfish: Prawns and mussels contain smaller amounts of omega-3s but can still contribute.

• Plant sources: Flaxseeds, chia seeds, hemp seeds, and walnuts provide alpha-linolenic acid (ALA), which the body can convert into DHA and EPA. However, conversion rates are low, often less than 10%.

• Algal oil: For vegetarians and vegans, algal oil is a direct source of DHA (and sometimes EPA), bypassing the inefficiency of ALA conversion.

When including more omega-rich foods, it is also important to consider overall dietary balance. Reducing excessive intake of processed seed oils can help ensure that  omega-3s are not outcompeted by omega-6s in metabolic pathways. 

For many people, eating enough oily fish can be challenging due to preference, availability, or sustainability concerns. In such cases, supplementation can provide a reliable way to ensure adequate omega-3 intake.

What matters most is the quality of the supplement. Choosing products that have been purified to remove contaminants such as mercury and PCBs is essential. Independent testing and sustainability certification can also provide reassurance that the supplement is both safe and responsibly sourced. 

Our eyes are not passive cameras but dynamic, nutrient-hungry organs that depend on a delicate balance of inputs to function well. Omega-3 fatty acids are at the heart of this balance. DHA provides the very architecture of vision by shaping retinal membranes, while EPA creates a favourable biochemical environment that helps protect against inflammation and oxidative stress. Together, they influence not only the inner workings of the retina but also the protective layer on the eye’s surface that keeps vision smooth and comfortable.

Supporting vision health is not about waiting for problems to arise. It is about recognising that our eyes are in constant use, from the moment we wake up to the moment we fall asleep and giving them the raw materials they need to perform. With visual demands continually increasing, ensuring a steady intake of omega fatty acids is one of the most practical steps we can take for lifelong eye health.