Age-related macular degeneration (AMD) and screen-related eye strain drive most eye supplement sales. The research is strongest for one specific use: slowing AMD that has already reached the intermediate stage.
The US National Eye Institute's AREDS2 formula contains vitamin C 500 mg, vitamin E 400 IU, zinc 80 mg, copper 2 mg, lutein 10 mg and zeaxanthin 2 mg a day. The NEI states that "nutritional supplements cannot prevent AMD", and that the AREDS and AREDS2 formulas helped people with intermediate or late AMD, with no benefit for people with early AMD or no AMD. They also did not prevent cataract.
The NEI found no significant change in effectiveness when zinc was lowered to 25 mg. In AREDS2, people who ate little lutein and zeaxanthin gained the most from adding them.
- Omega-3 (fish oil): in the DREAM trial, 3,000 mg a day of EPA and DHA for a year was no better than an olive-oil placebo for dry eye symptoms. Adding omega-3 to the AREDS formula also had no overall effect on advanced AMD.
- Bilberry: a systematic review found that the most rigorous placebo-controlled trials did not support bilberry for night vision.
- Vitamin A / beta-carotene: the original AREDS formula's beta-carotene is not recommended for current or former smokers; in AREDS2, former smokers taking it had more lung cancer.
- If you have been told you have intermediate AMD, ask your eye doctor whether an AREDS2 formula is right for you, and compare labels against the doses above.
- If your eyes are healthy, no supplement has been shown to prevent AMD. Leafy greens are a good food source of lutein and zeaxanthin.
- For screen strain or dry eyes, see an optometrist; the supplement evidence is weak.
- Claims to reverse cataracts, glaucoma or macular degeneration.
- Lutein and zeaxanthin below 10 mg and 2 mg in a product sold for AMD.
- Beta-carotene in a product aimed at smokers or former smokers.
Sources: NEI, AREDS/AREDS2 frequently asked questions · DREAM Study Group 2018, omega-3 for dry eye · Canter & Ernst 2004, bilberry for night vision