Do carrots or fish oil improve eyesight?

Almost every week a grandmother tells a fussy child, with total conviction, that they will never need glasses if they simply finish their carrots. It is one of the most affectionately delivered pieces of advice I hear in clinic, and the child usually needs glasses anyway, right on schedule, because short-sightedness is about the shape of the eye and carrots were never going to change that. I would not tell any grandmother her belief is foolish, because it is not. It has a true story hiding inside it. The trouble is what the story got turned into by the time it reached the dinner table.

Why does everyone say carrots are good for your eyes?

Because vitamin A really is essential for sight, and its absence really does cause blindness. Severe vitamin A deficiency, what doctors call xerophthalmia, starts with night blindness, difficulty seeing in dim light, and in its worst form progresses to permanent damage to the front of the eye. It remains, right now, the world's leading preventable cause of childhood blindness, and it is estimated that a quarter to half a million vitamin A deficient children go blind every year, with roughly half of them dying within the following year from the infections that deficiency also makes more dangerous. That is not folklore. That is a real disease, driven by genuinely inadequate diets, and it is why the carrot myth was never entirely invented from nothing.

What happened next is the part that goes wrong. A true fact about a deficiency disease became a general belief that more of the vitamin is always better, for any child, in any amount. That is not how vitamin A works, and it is not how a well fed child's eyesight works either. Even mild, subclinical deficiency matters, in the settings where it occurs, because it can raise a child's risk of infections and slow growth as well as affect the eyes. That is a further reason the underlying disease deserves to be taken seriously. It is not a reason to treat every child's dinner plate as a battleground against a disease that, in a well nourished household, was never actually present.

If a little vitamin A prevents blindness, does more sharpen eyesight?

No, and this is the part I most want a tired parent to actually absorb, because it is genuinely reassuring rather than a disappointment. The body needs only a relatively small amount of vitamin A for healthy vision. Once that need is met, which an ordinary varied diet does easily, eating more of it will not improve your child's eyesight or keep them out of glasses. The arithmetic that runs one way, severe deficiency causes real blindness, simply does not run backwards into extra vitamin A producing extra sharpness.

A child who needs glasses needs them because of the shape of their eye, how it focuses light, not because of what was on their plate that week. If your child has just been told they need glasses, this is what happens next, and it has nothing to do with the vegetables you did or did not manage to get into them.

Should I give my child fish oil for their eyes?

I would not, on the current evidence. The most careful trial evidence available looked at adding long chain fish oil fats, the kind marketed for brain and eye development, to the formula given to healthy full-term babies. Across the studies that measured visual acuity, roughly as many found a benefit as found none, and the review's own conclusion was that routine supplementation cannot be recommended on this evidence. A separate, more recent review of the wider literature on fish oil and vision reached a similarly unsatisfying place: it describes the studies as genuinely contradictory, with about as many showing an effect as showing nothing at all.

I say this carefully because I do not want it heard as fish oil being dangerous. It is not that. It is that the honest answer, for a healthy child eating reasonably, is that the evidence simply does not show a fish oil supplement sharpening a child's sight, and I am not going to tell a parent to spend money on something the trials cannot back up.

I understand why the bottle on the pharmacy shelf is tempting. It is a concrete action, something to do rather than something to wait on, and it comes with a picture of a bright eyed child on the label. But a concrete action is only worth taking if it actually does something, and on the trials we have, this one does not reliably move the number that matters, how sharply a child sees.

He is a fussy eater. Will his eyes suffer for it?

Ordinary fussiness, the kind almost every parent of a preschooler describes to me, is not the same thing as the deficiency that causes eye damage. That deficiency is a state of genuinely inadequate nutrition sustained over time, the kind seen where diets are chronically short on more than one food group, not a child who refuses broccoli but eats everything else. If your child's diet worries you generally, that is a conversation worth having with your paediatrician about growth and nutrition as a whole. It is not, on its own, a reason to buy an eye vitamin from the pharmacy shelf.

What actually protects a fussy eater's eyesight is the same thing that protects any child's eyesight: being checked when something specific is wrong, not a bottle of capsules standing in for the check.

I would rather a worried parent brought me the actual concern, a squint, a lazy looking eye, a habit of sitting close to the television, than went to a pharmacy first. A supplement cannot rule anything in or out. An eye check can, and it takes about the same amount of effort to arrange.

What foods actually help a child's eyes, then?

Vitamin A is not a carrot exclusive. Dark leafy greens, brightly coloured vegetables, dairy and fish all carry it, which is one more reason a single vegetable was never going to be the decisive factor either way. A varied diet is worth having for a child's health for a long list of reasons that have nothing to do with eyesight specifically, growth, immunity, energy, and I encourage it for all of those reasons. I simply will not tell a parent it will sharpen vision beyond what their child's eyes were already built to do, because that particular promise is not one the evidence keeps.

Can diet slow down my child's short-sightedness?

Not through carrots or fish oil, no. Short-sightedness in children is a subject I take seriously with every family in front of me, and I understand exactly why a parent goes looking for something to feed a child rather than something to change about their routine. But the tools that actually have evidence behind them are not on the dinner table. Time spent outdoors has real, repeatedly shown protective value, and I have written separately about why two hours outside is worth building into an ordinary week and about why short-sightedness is becoming so common in children in the first place. For some children, a specialist may discuss specific medical treatments directly with you. None of that runs through a supplement, and I would rather point a worried parent towards the two hours outdoors than towards a vitamin bottle, because one of those is backed by evidence and the other is backed by hope.

Carrots and dim light are two very different corners of the same family of eye myths parents carry from their own childhoods, and I have gathered the fuller list, including the one myth that genuinely does cost children their sight, in one place. This is the gentle one. Eat the carrots for dinner and for the rest of your child's health. Just do not expect them to do the one job the myth promises.

Common questions

References

1. World Health Organization · Vitamin A deficiency · www.who.int
2. Long chain polyunsaturated fatty acid supplementation in infants born at term, Cochrane Database of Systematic Reviews, 2017 · pubmed.ncbi.nlm.nih.gov
3. Impact of n-3 polyunsaturated fatty acid supplementation on visual health throughout the life cycle: a systematic review, Prostaglandins, Leukotrienes and Essential Fatty Acids, 2025 · pubmed.ncbi.nlm.nih.gov
4. American Academy of Ophthalmology · Common eye and vision myths and facts · www.aao.org

By Dr Chan Li Yen. General information only. It does not replace a consultation. If you are worried about your child's eyes or vision, please see an eye doctor.