Omega-3 against childhood myopia: what a new study has shown

The British Journal of Ophthalmology published a study from Hong Kong that assessed the association between the usual diet of 6-8 year old children and the risk of myopia. The participants were 1005 schoolchildren from the population-based Hong Kong Children Eye Study. The children underwent a full ophthalmological examination (including cycloplegic refraction) and measured axial length of the eye - an objective marker that increases as myopia progresses. In parallel, parents filled out a validated questionnaire on the frequency of consumption of ~280 products grouped into 10 categories (cereals/noodles/rice, vegetables/legumes, fruits, meat, fish, eggs, dairy, drinks, dim sum/snacks/fats/oils, soups). The model took into account age, gender, BMI, the amount of "near" work, time outdoors and family predisposition (myopia in parents).

Background of the study

Myopia in children is growing everywhere and especially rapidly in East Asia: classical estimates predict that by 2050 about half of the world's population will be nearsighted, and high myopia will be ~10%, which dramatically increases the risk of retinal detachment, glaucoma and maculopathy. The risk level is influenced not only by heredity, but also by lifestyle: less time outdoors and more continuous "near" work. A large randomized trial in Guangzhou showed that an additional 40 minutes of time outdoors each school day significantly reduced the incidence of myopia over three years of observation.

In parallel, ophthalmology is increasingly looking to nutrition as an additional lever of prevention. The retina is extremely rich in docosahexaenoic acid (DHA), a key omega-3 fatty acid that affects the fluidity of photoreceptor membranes, signal transmission, and the resistance of ocular tissue to damage; in animals and in early human studies, omega-3 supplements have been associated with improvements in a range of visual functions and neuroprotection. Biologically plausible mechanisms include improved choroidal blood flow, an anti-inflammatory effect, and a possible reduction in scleral hypoxia, which experimentally accelerates axial elongation of the eye - the “driver” of myopia progression. But until recently, we have had little “human” data specifically on the relationship between normal diet and myopia markers.

Against this background, new observations are emerging: independent groups have reported associations between higher omega-3 intake (especially EPA/DHA) and a lower risk of severe myopia in adolescents, as well as inverse associations between saturated fats and myopia metrics. Experimental models in humans and animals have also suggested that omega-3 may moderate myopic shift and axial elongation. But these signals require verification in a well-characterized pediatric population with objective ophthalmologic measurements, controls for time outdoors, “near” work, and family history.

A recent paper in the British Journal of Ophthalmology fills this gap: in a population-based cohort of 1,005 children aged 6–8 years from the Hong Kong Children Eye Study, the authors compared a dietary questionnaire (≈280 products) with cycloplegic refraction and axial length – an objective marker of myopia progression – and accounted for key confounders. The result was an inverse relationship between omega-3 intake and both myopia risk and axial length; for saturated fats, the picture was reversed. These are observational data and causality has not been proven, but they fit into a growing body of work and provide a logical vector for prospects and interventions.

Key Results

The baseline prevalence of myopia was 27.5% (276 children). The higher the rational intake of omega-3 polyunsaturated fatty acids (ω-3 PUFA), the lower the risk of myopia and the shorter the axial length; in parallel, the refraction was less "minus" (shift to less myopia). The mirror picture was observed in children from the upper quartile of saturated fats: they had a longer axial length and a more pronounced myopic refraction. None of the other nutritional factors in the analysis showed consistent links with myopia. The authors emphasize: this is an observational study - it speaks of links, but does not prove causality, but this is the first large "human" confirmation of a protective association between ω-3 and myopia markers.

Why is this important in practice?

The global epidemic of myopia is accelerating, especially in East Asia; by 2050, myopia is predicted to affect half the world’s population. Today, we know the “big three” modifiable factors: more time outdoors, less continuous near work, and screen control. The new work adds a potential nutritional lever: a diet rich in ω-3 PUFAs (primarily fish and seafood) is associated with shorter axial length and a smaller shift in myopia already in early school age. Conversely, excess saturated fats (butter, palm oil, fatty red meat, ultra-processed snacks) are associated with longer eyes and a greater risk of myopia. This fits into the ophthalmological context: ω-3 has long been studied in dry eye and age-related macular degeneration, and now a possible role in myopia in children.

How it might work (authors' hypotheses)

The key idea is choroidal blood flow. Omega-3s can improve microcirculation and oxygen delivery across the choroid, thereby reducing scleral hypoxia, a factor that in experimental models accelerates eyeball elongation and myopia progression. In real-world data, this was reflected by a shorter eye axis in children with higher omega-3 intake. In contrast, a diet rich in saturated fats may worsen the vascular and metabolic environment, indirectly supporting scleral stretch and axial length growth. These are currently biologically plausible explanations that require direct mechanistic confirmation in humans.

Important limitations

This is a cross-sectional observation: dietary questionnaires reflect a “snapshot” of habits and depend on memory, while refractive shifts develop over years. The study did not include objective biomarkers (e.g., omega-3 in the blood), so there may be errors in diet classification. Finally, Hong Kong is a region with one of the highest myopia rates; the transferability of the results to other ethnic and behavioral contexts (less screens, more outdoors) remains to be tested. The authors explicitly call for prospective cohorts and randomized nutritional studies, where the endpoints are not only axial length, but also the risk of myopia and the rate of its progression.

What This Means for Parents - Careful Steps to Take Today

• Put together a “fish week”. 1-2 servings of fatty fish (salmon, mackerel, sardines) + white fish/seafood for variety; for vegetarians - proven sources of ALA (flax seeds/oil, chia, walnuts), if necessary - DHA/EPA supplements in agreement with the pediatrician.
• Keep saturated fats and ultra-processed snacks in check: It's good for your heart and possibly your eyes.
• Don't forget about the "outdoor dose of light." 1.5-2 hours a day outdoors is one of the most reliable factors in preventing myopia, confirmed in RCTs and real practice. (Nutrition is a supplement, not a replacement.)
• Hygiene of visual loads. "20-20-2": every 20 minutes of close work - 20 seconds of looking into the distance; and - up to 2 hours in the fresh air daily.

What will science do next?

The priorities are clear: (1) prospective studies with objective ω-3 markers (DHA/EPA levels) and axial length growth tracking; (2) interventions - dietary and/or ω-3 supplements with detailed monitoring of outdoor time and screen time; (3) mechanisms - choroidal blood flow imaging, scleral and retinal metabolomics; (4) stratification by familial risk and baseline biomarkers to understand who may benefit most. Only then can we move from associations to confident recommendations.

Source: Zhang XJ et al. Dietary omega-3 polyunsaturated fatty acids as a protective factor of myopia: the Hong Kong Children Eye Study. British Journal of Ophthalmology, 2025. DOI: 10.1136/bjo-2024-326872.