Dry eye occurs when your eyes do not produce enough tears to keep them well lubricated and healthy. Aging, hormonal changes, allergies, the environment, excessive screen time, and certain medical conditions are all common causes of dry eye.

Eye drops and ointments are commonly used to treat dry eye syndrome. Many people also turn to alternative remedies for relief. Fish oil—derived from the tissues of oily fish, such as salmon and mackerel—is rich in omega-3 fatty acids that have proven benefits for eye health.

Read on to learn more about how fish oil may help reduce symptoms of dry eye syndrome. 

Health Benefits 

Omega-3s in fish oil offer a number of health benefits thanks to their antioxidant and anti-inflammatory properties.

There are three primary omega-3s that are beneficial for body and brain health: 

α-linolenic acid (ALA)eicosapentaenoic acid (EPA)docosahexaenoic acid (DHA)

These potent nutrients have been extensively studied and have been found to lower the risk of chronic diseases, including arthritis, cancer, and heart disease.

There is ongoing research exploring the benefits of omega-3 fatty acids for eye health. DHA plays a particularly important role in eye function. Some research suggests that omega-3s may help prevent vision impairment and blindness caused by macular degeneration.

A 2019 review of 34 different studies found that omega-3 supplementation may help manage dry eye disease, but the evidence is inconsistent.

Researchers continue to explore the effects of DHA and other omega-3 fatty acids on preventing and treating eye-related conditions.

Possible Side Effects 

Fish oil is generally considered to be safe for most adults. Mild side effects include bad breath, foul-smelling sweat, headache, and gastrointestinal symptoms such as diarrhea, heartburn, and nausea.

Omega-3 supplements (including fish oil) may interact with medications for blood clotting, so speak with your healthcare provider before trying fish oil if you are taking any prescription medications. 

Dosage and Preparation 

There is currently no recommended dosage for daily intake of fish oil. However, there are guidelines to recommend 1.6 grams of alpha-linolenic acid (a type of omega-3 fatty acid) per day for men and 1.1 grams per day for women.

There is currently no recommended daily allowance for other types of omega-3s, such as EPA and DHA. However, a 250–500 milligram (mg) daily intake of EPA and DHA combined is enough for most adults.

Talk to your healthcare provider about the appropriate dosage for you.

If you’d rather not use fish oil dietary supplements, you can try adding more omega-3 fatty acids to your diet. Consuming omega-3 fatty acids through natural sources (e.g., salmon, mackerel, sardines) may help stimulate tear production and lubricate the eyes.

Taking flaxseed oil or other omega-3 supplements may also be effective. 

It’s best to take fish oil supplements with a meal that contains fat, as fat increases the body’s absorption of omega-3s.

What to Look For

Fish oil is available in capsule and liquid forms at health food stores, grocery stores, and some drugstores. With so many options available, it’s important to remember that not all fish oils are created equal. Always read the label carefully when shopping for fish oil/omega-3 supplements.

Check for the following: 

Type of omega-3: Ensure that the supplement you purchase contains EPA and DHA, the most important types of omega-3s for eye health.   Amount of omega-3s: Many supplements contain marginal amounts of omega-3s, so be sure to check the label for the amounts of omega-3s in each dose. A typical fish oil supplement provides approximately 1,000 mg/fish oil containing 180 mg EPA and 120 mg DHA, but doses vary. Absorption: Also known as “bioavailability,” this indicates how easily your body can use the nutrients in the fish oil. The less processed, the better. Natural fish oils are more easily absorbed than purified fish oils.   Product purity: Look for products that have either the GOED standard for purity or a third-party seal that indicates they’ve been tested by an independent lab and the contents are safe and contain what the label says. Freshness: When fish oil goes bad, it tends to have a rancid smell. Check the expiration date on any supplements you purchase and smell them every once in a while before consumption to ensure they are still fresh.  Be sure to refrigerate your fish oil once opened in order to prevent it from spoiling.

Important Considerations

If you increase your consumption of foods rich in omega-3s (e.g., salmon, mackerel), buying fish oil supplements for dry eyes may not be necessary. You should be able to get the recommended daily intake by consuming foods that are rich in omega-3s. 

If you are pregnant or breastfeeding, speak with your healthcare provider before using fish oil. Some types of fish contain heavy metals such as mercury, which is potentially dangerous for pregnant people.

A Word From Verywell

Dry eye syndrome can be a painful condition that impacts your quality of life. Fish oil may help improve eye health, but research results are inconsistent on just how beneficial it is for dry eye syndrome. It is possible to get enough omega-3s from food sources, such as sardines, salmon, and mackerel. Be sure to follow any treatments your healthcare provider has recommended.