TL;DR
Cataracts are one of the most common causes of vision loss worldwide, and they affect the majority of people over 65 to some degree. Surgery is effective, but it’s natural to wonder whether there’s anything you can do earlier on to slow things down.
Antioxidants are often mentioned in that conversation, and for good reason. There’s a growing body of research exploring whether nutrients like vitamins C and E, lutein and zeaxanthin can protect the lens of the eye from the damage that leads to cataracts. The short answer is that the evidence is promising but mixed.
How cataracts form and why oxidative stress matters
A cataract develops when proteins in the lens of your eye start to break down and clump together. This creates cloudy patches that block or scatter light, making your vision blurry, hazy or washed out. The process usually happens gradually over years.
One of the main drivers of this protein damage is oxidative stress. Your lens is constantly exposed to light, oxygen and UV radiation, all of which generate molecules called free radicals. In small amounts, your body handles these through its own antioxidant defences, including glutathione, vitamin C and various enzymes. But as you age, those defences weaken. Free radicals start to accumulate, damaging the proteins and lipids in the lens.
A 2024 review published in Biomolecules confirmed that oxidative stress plays a central role in cataract formation, and that dietary antioxidants like vitamins C and E, along with lutein and zeaxanthin, can help neutralise free radicals in the lens. The question is how well that translates into real-world prevention.
What the observational studies show
When researchers look at large groups of people over time, the results tend to be encouraging. Multiple cohort studies have found that people who consume more antioxidant-rich foods have a lower risk of developing cataracts.
One of the most widely cited pieces of evidence comes from a study at King’s College London, which tracked over 1,000 pairs of female twins. Researchers found that women who consumed more vitamin C from food had a 33% lower risk of cataract progression over a 10-year period. Their lenses were also clearer overall.
Data from the Nurses’ Health Study in the US found a similar pattern. Women under 60 who consumed at least 363mg of vitamin C daily had a 57% lower risk of cortical cataracts compared to those with lower intakes.
Lutein and zeaxanthin, two carotenoids found in leafy greens and eggs, have also been linked to lower cataract risk in observational research. These pigments are present in the human lens and are thought to filter harmful blue light while acting as localised antioxidants.
The evidence gets more complicated
Observational studies are useful, but they have limits. People who eat more fruit and vegetables also tend to exercise more, smoke less and generally live healthier lives. It’s difficult to separate the effect of one nutrient from the broader pattern.
That’s why randomised controlled trials matter, and here the results are less clear-cut. The original AREDS trial and its successor, AREDS2, both run by the US National Eye Institute, tested specific antioxidant formulations in thousands of participants. While the supplements significantly reduced the risk of advanced age-related macular degeneration, they did not show a meaningful effect on cataract development.
A separate trial in India gave participants a combination of vitamin C, beta-carotene and vitamin E three times a week for five years. Again, there was no significant difference in cataract formation between the supplement and placebo groups.
A 2024 review in Biomolecules concluded that further clinical studies are needed before evidence-based recommendations can be made for antioxidant supplementation specifically aimed at cataract prevention.
Which antioxidants have the strongest evidence?
Despite the mixed results from supplement trials, certain nutrients consistently appear in the research as relevant to lens health.
- Vitamin C has some of the strongest associations. The lens of the eye contains one of the highest concentrations of vitamin C anywhere in the body, and levels decline with age and cataract severity. Good dietary sources include peppers, citrus fruits, strawberries, broccoli and potatoes.
- Vitamin E protects cell membranes from oxidative damage and has been linked to lower cataract risk in several studies. Nuts, seeds and vegetable oils are the best sources.
- Lutein and zeaxanthin are concentrated in the lens and macula, where they filter blue light and reduce oxidative stress. You’ll find them in spinach, kale, eggs and sweetcorn.
Related read: 10 High Antioxidant Foods
Food vs. supplements for cataracts
One consistent thread across the research is that antioxidants from food tend to show stronger protective effects than those from supplements. Whole foods contain a complex mix of nutrients that work together, and the body absorbs them differently from isolated compounds in capsule form.
That said, supplements are still very useful for people who struggle to get enough nutrients through diet alone. If you’re considering one for eye health, look for a supplement formula based on the AREDS2 study, which includes lutein, zeaxanthin, vitamins C and E, zinc and copper.
Other ways to reduce your cataract risk
Antioxidants are one piece of the puzzle. Other well-supported strategies include:
- Stopping smoking (which directly increases oxidative stress in the lens)
- Managing blood sugar if you have diabetes
- Having regular eye tests so changes can be spotted early
What this means for you
The research suggests that a diet rich in antioxidants, particularly from whole foods, is likely to support lens health and may help delay cataract development.
What you can do is simple: eat plenty of colourful fruit and vegetables, include foods rich in vitamins C and E, get regular eye tests and protect your eyes from UV damage. These are small, consistent steps with a strong foundation behind them.
