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Eye Health Knowledge Centre: Eye Health Supplements, Eye Checks and Surgeon-Written Guides
Eye health supplements help one proven group: people with intermediate age-related macular degeneration (AMD). For them, the AREDS2 formula cuts the risk of progressing to advanced AMD by about 25% (US National Eye Institute). For everyone else, a balanced diet, no smoking, UV-blocking sunglasses and an eye test every two years do more. Our retina surgeons, Doç. Dr. Muhammet Derda Özer and Op. Dr. Aysan Bayram, and Prof. Dr. Ahmet Satıcı review the guides in this knowledge centre.
Good eye health is mostly about catching problems early and protecting the eyes you have. This knowledge centre brings together everything we have written about eyes: plain-English explanations of eye conditions and symptoms, guides to each type of eye surgery, side-by-side comparisons, an A–Z glossary of eye terms, and practical advice for anyone thinking about treatment abroad.
Every guide is written for patients, not doctors, and checked by one of our three surgeons in Istanbul: Prof. Dr. Ahmet Satıcı (cataract, premium lenses, laser, ICL, eyelids, squint and glaucoma), Doç. Dr. Muhammet Derda Özer (Doç. means Associate Professor; cornea, keratoconus, retina, uveitis and cataract) and Op. Dr. Aysan Bayram (cataract, laser and retinal disease). Medical facts come from sources such as the NHS, the US National Eye Institute (NEI), the American Academy of Ophthalmology (AAO) and the World Health Organization, and each guide lists them.
Why it matters: according to the World Health Organization (fact sheet, February 2026), at least 2.2 billion people worldwide have a near or distance vision impairment, and for at least 1 billion of them it could have been prevented or has not yet been addressed. Many of the leading causes, including cataract, glaucoma, diabetic retinopathy and macular degeneration, are covered in the guides below.
Start with the most common question we are asked, about eye health supplements, or jump straight to the guide hubs.
Eye health supplements: what actually works?
The only eye health supplement with strong trial evidence is the AREDS2 formula, and it is for people who already have intermediate AMD (or late AMD in one eye). Two large US trials run by the National Eye Institute, AREDS (4,757 people aged 55–80) and AREDS2 (4,203 people aged 50–85), found that the formula reduces the risk of progressing from intermediate to advanced AMD by about 25%. It does not stop AMD from starting, and it does not bring back vision you have already lost.
What is in the AREDS2 formula?
| Ingredient | Daily dose in the AREDS2 formula (NEI) |
|---|---|
| Vitamin C | 500 mg |
| Vitamin E | 400 IU |
| Zinc | 80 mg |
| Copper (as cupric oxide) | 2 mg |
| Lutein | 10 mg |
| Zeaxanthin | 2 mg |
| Beta-carotene | none |
The NEI says you cannot get this mix of vitamins and minerals from food or from a regular multivitamin. That is why a general "eye vitamin" or a standard multivitamin is not the same as the formula that was tested.
What the research says does not work
| Claim you may see | What the evidence shows |
|---|---|
| "Supplements prevent macular degeneration" | AREDS2 supplements do not prevent AMD in people who don't have it (NEI). |
| "Eye vitamins prevent cataracts" | AREDS and AREDS2 supplements had no effect on cataract (NEI). |
| "Omega-3 capsules protect the macula" | In AREDS2, omega-3 supplements had no effect on AMD or cataract (NEI). |
| "Fish-oil capsules cure dry eyes" | In the DREAM trial (535 people, 3 g of omega-3 a day for 12 months, published in the New England Journal of Medicine in 2018), omega-3 did no better than an olive-oil placebo. |
| "Supplements can restore lost sight" | The AAO says vitamins and supplements are not a cure for eye disease and won't give back vision you have already lost. |
Are eye supplements safe?
Mostly, but high doses carry real risks, so take a high-dose formula only on your eye doctor's advice. The older AREDS formula contained beta-carotene, which increases the risk of lung cancer in people who smoke or used to smoke; the NEI advises current and former smokers to take the AREDS2 formula without it. Zinc is the other point to watch. The NHS says adults need about 9.5 mg (men) or 7 mg (women) a day, that high doses reduce copper absorption and can lead to anaemia and weaker bones, and that you should not take more than 25 mg of zinc supplements a day unless a doctor advises it. The AREDS2 dose of 80 mg is well above that, which is why copper is included and why it is a treatment for diagnosed AMD, not an everyday tonic.
Eye health supplements in the UK: how to choose
If you are in the UK and your optometrist or eye doctor has found intermediate AMD, ask them whether an AREDS2-type supplement suits you. Then check the label against the doses in the table above: a product with different amounts is not the formula that was tested. If you have no AMD, the NHS guidance is that most people can get the vitamins and minerals they need from a varied diet. Tell your GP or pharmacist about any supplement you take, especially if you take other medicines.
Best food for eye health: fruit, nuts and fish
No single "superfood" protects your eyes, but a diet rich in leafy greens, colourful fruit, nuts and oily fish supplies the nutrients the AREDS research focused on. The AAO reports that a Mediterranean-style diet can reduce AMD progression by 25% or more.
| Nutrient | Best fruit and vegetables | Best nuts and seeds | Other sources |
|---|---|---|---|
| Vitamin C | Oranges, grapefruit, kiwifruit, strawberries, tomatoes, peppers, broccoli | — | — |
| Vitamin E | Avocados | Almonds, sunflower seeds | Olive oil |
| Lutein and zeaxanthin | Kale, spinach, chard, broccoli, asparagus, raspberries, papaya, peaches, mangoes | — | — |
| Omega-3 and omega-6 | — | Walnuts | Salmon, trout, sardines, sunflower oil |
| Zinc | Legumes (beans, lentils) | Seeds | Meat, seafood, dairy, eggs |
Source: AAO, "Diet and Nutrition" (April 2025). The NEI also recommends dark leafy greens such as spinach, kale and collard greens, and fish high in omega-3 such as salmon, tuna and halibut.
So what is the best fruit for eye health? Variety beats any single fruit: citrus and kiwifruit for vitamin C, and orange-yellow fruit such as mangoes, papaya and peaches for lutein and zeaxanthin. The best nuts for eye health are almonds and sunflower seeds for vitamin E, and walnuts for omega fatty acids.
Eye health check: how often should you have one?
Most adults should have an eye test every two years, or more often if their optometrist advises it. That is the NHS recommendation, and Moorfields Eye Hospital NHS Foundation Trust describes a sight test as an important health check that can pick up early signs of eye conditions before you notice any symptoms. The NEI adds that a dilated eye exam is the only way to check for many eye diseases early, when they are easier to treat.
Who gets a free NHS eye test?
In England, the NHS lists these groups as eligible for a free NHS sight test, usually every two years:
Your optometrist can offer an earlier NHS test if they think it is clinically needed. Rules differ in Scotland, Wales and Northern Ireland, so check locally.
- children under 16, and young people aged 16–18 in full-time education
- adults aged 60 or over
- people diagnosed with diabetes or glaucoma, or registered as partially sighted or blind
- people aged 40 or over whose parent, brother, sister or child has glaucoma, or who an ophthalmologist has told they are at risk of glaucoma
- people who receive certain benefits or hold an NHS HC2 certificate
When not to wait for a routine check
The NHS says to go to A&E or call 999 if you suddenly cannot see from one or both eyes, or suddenly have severe eye pain. Get urgent advice (GP or NHS 111) for sudden changes in vision, flashing lights, a dark shadow moving across your vision, or a red and painful eye. These need care where you are now, not a trip abroad.
Everyday eye health: the habits that matter most
For most people, protecting eye health comes down to six habits (NEI, "Keep Your Eyes Healthy", September 2025):
Have regular eye checks
, and know your family's eye history: conditions such as glaucoma can run in families.
Eat well
plenty of dark leafy greens, and fish high in omega-3.
Don't smoke
Smoking increases the risk of macular degeneration and cataracts, and can harm the optic nerve.
Wear sunglasses that block 99 to 100% of both UVA and UVB radiation
Use protective eyewear
for sport, construction work and DIY.
Rest your eyes on screens with the 20-20-20 rule
every 20 minutes, look at something about 20 feet (6 metres) away for 20 seconds.
Keeping active and eating well also lowers the risk of diabetes and high blood pressure, two conditions that can lead to eye and vision problems.
Eye health guides, by topic
Eye health problems and the basics
Eye conditions and symptoms A–Z
Clear explanations of the most common eye health problems: astigmatism, dry eyes, lazy eye, squint, short-sightedness, sudden blurred vision and more, with the symptoms that mean you should see a doctor.
Reviewed by: all three surgeons, by specialty
Eye conditions and symptoms A–ZEye glossary A–Z
Short definitions of the words you will hear at an eye appointment, from cornea and macula to OCT and trifocal lens.
Reviewed by: all three surgeons
Eye glossary: eye terms explained A–ZComparisons
Side-by-side answers to "X or Y?" questions: laser vs LASIK, short-sightedness vs long-sightedness, cataract vs glaucoma, contact lenses vs laser over ten years, and how to choose between a large chain and a named surgeon.
Reviewed by: all three surgeons, by topic
Eye-care comparisons, side by sideTreatment guides
Laser eye surgery guides
LASIK vs SMILE vs PRK, what changed with SMILE Pro, no-touch laser, the day-by-day recovery timeline and when it is safe to fly.
Lead surgeons: Prof. Dr. Ahmet Satıcı and Op. Dr. Aysan Bayram
Laser eye surgery guidesLens and cataract guides
Lens replacement vs laser after 50, trifocal vs EDOF vs monofocal lenses, honest pros and cons of lens surgery, and NHS cataract waiting times.
Lead surgeons: Prof. Dr. Ahmet Satıcı for premium lenses; all three surgeons for cataract
Lens replacement and cataract guidesKeratoconus and cornea guides
Keratoconus symptoms and stages, cross-linking vs corneal rings vs transplant, whether laser or ICL is possible with keratoconus, and why early treatment matters in teenagers.
Lead surgeon: Doç. Dr. Muhammet Derda Özer
Keratoconus and cornea guidesRetina and glaucoma guides
Warning signs of retinal detachment, floaters and when vitrectomy helps, glaucoma symptoms and surgery options (SLT, MIGS, trabeculectomy), and macular degeneration, including the supplement question above.
Lead surgeons: Doç. Dr. Muhammet Derda Özer and Op. Dr. Aysan Bayram (retina); Prof. Dr. Ahmet Satıcı (glaucoma)
Retina and glaucoma guidesEyelid and cosmetic guides
Hooded eyelids, blepharoplasty recovery week by week, dark circles and puffy under-eyes, combining lens surgery and an eyelid lift in one trip, and which "trend" procedures carry real risk.
Lead surgeon: Prof. Dr. Ahmet Satıcı
Eyelid and cosmetic eye guidesPlanning treatment
Treatment abroad guides
What to check before booking eye surgery abroad, how to choose an eye surgeon in Istanbul, why surgery in Turkey costs less, and where to stay while you recover.
Reviewed by: {{reviewer for travel guides}}
Where to go next
| If you want to… | Go to |
|---|---|
| see every treatment we offer and which surgeon leads it | All eye treatments |
| compare costs | Price list: all eye treatments in GBP, EUR, USD and SAR — prices include your examination and scans, surgery, medication, follow-up checks in Istanbul, an interpreter and a coordinator; hotel and airport transfers are extra |
| read about the three surgeons | Our eye surgeons |
| hear from past patients | Patient reviews and video stories |
| check safety before you book | Is eye surgery in Turkey safe? What to check before you book |
| meet the team and interpreters | About us: our surgeons, team and interpreters |
Questions about eye health and eye health supplements
Only for a specific group. The AREDS2 formula reduces the risk of intermediate AMD progressing to advanced AMD by about 25%, according to the US National Eye Institute. It does not prevent AMD, has no effect on cataract, and won't restore lost vision. For people without AMD, there is no good evidence that eye supplements protect your sight.
People whose eye doctor has found intermediate AMD in one or both eyes, or late AMD in one eye. Current and former smokers should use the AREDS2 version without beta-carotene. Because the zinc dose (80 mg) is high, take it only on an eye doctor's advice.
The best trial says probably not on its own. In the DREAM study, 3 g of omega-3 a day for a year was no better than an olive-oil placebo for dry-eye symptoms or signs. Oily fish is still a healthy part of an eye-friendly diet, and a doctor can suggest dry-eye treatments that do work for your type.
Low-dose products are generally safe, but read the label. The NHS advises not to take more than 25 mg of zinc supplements a day unless a doctor advises it, and beta-carotene raises lung-cancer risk in smokers and former smokers. Check with your GP or pharmacist if you take other medicines.
The NHS recommends an eye test every two years for most adults, more often if your optometrist advises it. People with diabetes, glaucoma or a family history of glaucoma may need more frequent checks. An eye test can pick up early signs of eye conditions before you notice symptoms.
For some people. In England, NHS sight tests are free for children under 16, 16–18-year-olds in full-time education, adults aged 60 or over, people with diabetes or glaucoma, people aged 40 or over with a close relative who has glaucoma, and people on certain benefits. Everyone else pays the optician's fee.
There is no single best fruit. Citrus fruit, kiwifruit and strawberries provide vitamin C, and raspberries, mangoes, papaya and peaches provide lutein and zeaxanthin, the pigments concentrated in the macula. Eat a variety, alongside dark leafy greens.
World Sight Day, the global eye health day coordinated by the International Agency for the Prevention of Blindness (IAPB), is held on the second Thursday of October every year. In 2026 it fell on 8 October, with the theme "Love Your Eyes".
Worldwide, the World Health Organization lists refractive errors, cataract, diabetic retinopathy, glaucoma and age-related macular degeneration among the leading causes of vision impairment. Our conditions A–Z hub explains each one and the symptoms to watch for.
Sources for the facts on this page
- US National Eye Institute, "AREDS 2 supplements for age-related macular degeneration" (updated 22 Jun 2021): AREDS2 doses (vitamin C 500 mg, vitamin E 400 IU, zinc 80 mg, copper 2 mg, lutein 10 mg, zeaxanthin 2 mg, no beta-carotene); for intermediate AMD in one or both eyes, or late AMD in one eye; can't prevent early AMD becoming intermediate; can't get this mix from food or regular multivitamins; beta-carotene and lung cancer in smokers/former smokers. https://www.nei.nih.gov/eye-health-information/eye-conditions-and-diseases/age-related-macular-degeneration/nutritional-supplements-age-related-macular-degeneration
- US National Eye Institute, "About AREDS and AREDS2": about 25% lower risk of progression from intermediate to advanced AMD; no effect on cataract; omega-3 no effect on AMD or cataract; AREDS 4,757 participants aged 55–80, AREDS2 4,203 aged 50–85; smokers should avoid beta-carotene. https://www.nei.nih.gov/research/clinical-trials/age-related-eye-disease-studies-aredsareds2/about-areds-and-areds2
- DREAM study (Dry Eye Assessment and Management), University of Pennsylvania study centre: 535 participants, 27 US centres, 3 g omega-3 daily for 12 months, no benefit over olive-oil placebo; published in the New England Journal of Medicine, April 2018 (Asbell PA et al., "n−3 Fatty Acid Supplementation for the Treatment of Dry Eye Disease", NEJM 2018;378:1681–1690). https://www.med.upenn.edu/cpob/dream/ · https://www.nejm.org/doi/full/10.1056/NEJMoa1709691
- American Academy of Ophthalmology, "Diet and Nutrition" (8 Apr 2025): supplements are not a cure and won't restore lost vision; foods for vitamin C, vitamin E, zinc, lutein/zeaxanthin and omega-3/omega-6 (including almonds, sunflower seeds, walnuts, raspberries, papaya, peaches, mangoes); Mediterranean diet reduces AMD progression by 25% or more. https://www.aao.org/eye-health/tips-prevention/diet-nutrition
- NHS, "Vitamins and minerals: Others" (zinc): adults need about 9.5 mg (men) / 7 mg (women) a day; high doses reduce copper absorption, leading to anaemia and weaker bones; no more than 25 mg zinc supplements a day unless advised by a doctor; you should get all the zinc you need from diet. https://www.nhs.uk/conditions/vitamins-and-minerals/others/
- NHS, "Visiting an optician" (reviewed 4 May 2023): eyes tested every 2 years, more often if advised; optometrists detect glaucoma, macular degeneration and cataracts. https://www.nhs.uk/nhs-services/opticians/visiting-an-optician/
- NHS, "How often can I have a free NHS sight test?" (reviewed 19 Apr 2023): every 2 years, earlier if clinically necessary. https://www.nhs.uk/nhs-services/opticians/how-often-can-i-have-a-free-nhs-eye-test/
- NHS, "Free NHS eye tests and optical vouchers" (reviewed 19 Jul 2023): eligibility list (under 16; 16–18 in full-time education; 60+; diabetes or glaucoma; registered partially sighted/blind; 40+ with parent, sibling or child with glaucoma; at risk of glaucoma; certain benefits; HC2). https://www.nhs.uk/nhs-services/opticians/free-nhs-eye-tests-and-optical-vouchers/
- Moorfields Eye Hospital NHS Foundation Trust, "Eye tests": most people should have a sight test every two years; a sight test can pick up early signs of eye conditions before symptoms appear. https://www.moorfields.nhs.uk/for-patients/your-eye-health/eye-tests
- NHS, "Vision loss" (reviewed 28 Aug 2025): A&E or 999 for sudden loss of sight or sudden severe eye pain; urgent GP/111 for vision changes, flashing lights, a dark shadow, a red and painful eye. https://www.nhs.uk/conditions/vision-loss/
- US National Eye Institute, "Keep Your Eyes Healthy" (11 Sep 2025): dilated eye exam; family history; dark leafy greens and omega-3 fish (salmon, tuna, halibut); smoking and AMD, cataract, optic nerve; sunglasses blocking 99–100% of UVA and UVB; protective eyewear; 20-20-20 rule; diabetes and high blood pressure. https://www.nei.nih.gov/learn-about-eye-health/healthy-vision/keep-your-eyes-healthy
- World Health Organization fact sheet, "Blindness and vision impairment" (10 Feb 2026): at least 2.2 billion people with near or distance vision impairment, at least 1 billion preventable or not yet addressed; leading causes. https://www.who.int/news-room/fact-sheets/detail/blindness-and-visual-impairment
- International Agency for the Prevention of Blindness, "World Sight Day": second Thursday of October; 8 October 2026; theme #LoveYourEyes. https://www.iapb.world/world_sight_day
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