Skip to main content

Eye Conditions at a Glance

vitamin hand eye conditions

Vision problems affect many Americans. More than 3.4 million aged 40 and older are blind or visually impaired. However, some estimates suggest that as many as 21 million Americans have vision problems and that 80 million have potentially blinding eye diseases. Age-related macular degeneration, cataract, diabetic retinopathy, and glaucoma are the main causes of visual impairment and blindness in older Americans. Conventional treatments, such as surgery, are available for some eye conditions, but some people turn to dietary supplements to prevent them or to delay their progression.

What the Science Says


A cataract occurs when the lens of the eye becomes clouded, causing blurring or discoloration of vision. If vision loss from a cataract becomes severe enough to interfere with normal activities, surgery to remove the lens and replace it with an artificial one often helps.

  • Findings from a 2015 randomized controlled trial of 11,267 men from the Selenium and Vitamin E Cancer Prevention Trial (SELECT) Eye Endpoints Study indicate that long-term daily supplementation with selenium and/or vitamin E is unlikely to have a large beneficial effect on age-related cataract.
  • A 2014 Swedish epidemiologic study that included about 30,600 women looked at potential associations between antioxidant consumption and cataract formation. The study concluded that consuming antioxidants through diet may lower the risk of cataract formation.
  • However, a 2012 review article that included 9 clinical trials with almost 117,300 people determined that supplementing with the antioxidants vitamins C and E and beta-carotene does not prevent cataracts or slow their progression.
  • Results from AREDS2 showed that none of the modified formulations helped reduce the risk of progression to cataract surgery, although a subgroup of participants with low dietary lutein and zeaxanthin gained some protection.

Diabetic Retinopathy

In diabetic retinopathy, an eye disease that occurs as a complication of diabetes, the blood vessels of the retina become damaged. This can cause vision distortion or loss.

  • A 2011 literature review stated that no dietary supplements have been shown to be helpful for diabetic retinopathy.


Glaucoma can damage the optic nerve, resulting in a loss of vision, starting with peripheral (side) vision. Early detection and treatment of glaucoma are important. There is little evidence to support using megavitamins, special diets, acupuncture, relaxation techniques, or therapeutic touch for glaucoma.

Side Effects and Risks

  • It’s important to follow your eye care professional’s instructions for treating eye conditions. Don’t use unproven approaches to replace conventional medical treatments.
  • Supplements containing certain antioxidants and zinc are recommended only for some people with AMD. For example, they are not recommended for those with early-stage AMD. If you have AMD, ask your eye care professional whether taking supplements is advisable.
  • Beta-carotene (which is in AREDS but not AREDS2 formulations) may increase the risk of lung cancer in current and former smokers and those who have been exposed to asbestos. 
  • Keep in mind that dietary supplements can cause health problems if not used correctly or if used in large amounts, and some may interact with medications you take.

For more information on eye health, visit the National Eye Institute (NEI) website.

For More Information

NCCIH Clearinghouse

The NCCIH Clearinghouse provides information on NCCIH and complementary and integrative health approaches, including publications and searches of Federal databases of scientific and medical literature. The Clearinghouse does not provide medical advice, treatment recommendations, or referrals to practitioners.

Toll-free in the U.S.: 1-888-644-6226

Telecommunications relay service (TRS): 7-1-1


Email: (link sends email)

Know the Science

NCCIH and the National Institutes of Health (NIH) provide tools to help you understand the basics and terminology of scientific research so you can make well-informed decisions about your health. Know the Science features a variety of materials, including interactive modules, quizzes, and videos, as well as links to informative content from Federal resources designed to help consumers make sense of health information.

Explaining How Research Works (NIH)

Know the Science: How To Make Sense of a Scientific Journal Article

Understanding Clinical Studies (NIH)


A service of the National Library of Medicine, PubMed® contains publication information and (in most cases) brief summaries of articles from scientific and medical journals. For guidance from NCCIH on using PubMed, see How To Find Information About Complementary Health Approaches on PubMed.


This publication is not copyrighted and is in the public domain. Duplication is encouraged.

NCCIH has provided this material for your information. It is not intended to substitute for the medical expertise and advice of your health care provider(s). We encourage you to discuss any decisions about treatment or care with your health care provider. The mention of any product, service, or therapy is not an endorsement by NCCIH.

Last Updated: September 2017