What Is the Difference Between Dry Eye and Allergic Conjunctivitis?

People with allergies may be used to symptoms that affect their eyes. But there is more than one condition that can cause these symptoms.

Dry eye and allergic conjunctivitis are 2 separate conditions that may have similar symptoms. Both conditions can also be connected to allergies.^1,2

What is dry eye?

Dry eye is a condition that happens if your eyes do not have enough tears. Our tears work to lubricate our eyes so our eyes function well and feel comfortable. Dry eye can be caused by decreased tear production or increased tear evaporation.³

Symptoms of dry eye include:³

• Burning feeling on eyes
• Eyes feeling gritty or sandy
• Other eye pain
• Blurry vision
• Red eyes

Causes of dry eye include age, side effects from medicine, or conditions such as certain autoimmune diseases.³

There is also a link between allergies and dry eye. Antihistamines, which are a common treatment for allergies, can cause dry eye. Additionally, irritants in the air, including allergens, can cause dry eye. It is possible that people with allergies are more likely to experience dry eye from irritants in the air.^1,3

What is allergic conjunctivitis?

For people with allergies, the body overreacts to allergens and produces histamines. Histamines cause inflammation. Allergic conjunctivitis happens when this inflammation caused by histamines affects the eyes. Allergies may also cause a runny or itchy nose and sneezing.^2,4

Symptoms of allergic conjunctivitis include:²

• Intensely itchy eyes
• Red or swollen eyes
• Watery eyes or a mucus-like discharge from the eyes

Allergic conjunctivitis can be seasonal or perennial. This relates to which allergens cause it.²

If your allergies are seasonal, they are triggered by allergens at certain times of the year, such as pollen. This means your allergic conjunctivitis would be worse at these times. Perennial allergies happen year-round. They may be caused by animals, dust, or mold.²

How can I tell whether I have dry eye or allergic conjunctivitis?

The causes of dry eye and allergic conjunctivitis are different, but the symptoms are similar. So it can be difficult to determine which condition is impacting your eyes. The easiest way to tell the difference between the conditions is itching. Intense itching is more likely to be caused by allergic conjunctivitis. But dry eye can cause mild itching.^3,4

Some people may experience dry eye and allergic conjunctivitis at the same time. If you are unsure which condition you have, contact your doctor. They may be able to provide a diagnosis. If you have a diagnosis, it may be easier to find a successful treatment.^3,4

Treatment for dry eye and allergic conjunctivitis

Some treatments for dry eye and allergic conjunctivitis overlap. For example, using eye drops, avoiding allergens or irritants, and maintaining clean contact lenses can help both conditions. However, some treatments can be specific to the condition.^3,4

Treatment for dry eye might include:³

• Using a humidifier
• Wearing protective eyewear
• Certain medicated eye drops
• Drugs to reduce eye inflammation or promote tear production

Treatment for allergic conjunctivitis is often similar to other treatment for allergies, such as anti-allergy oral drugs. But avoiding antihistamines may help prevent dry eye. Treatment can also include:^2,4

• Cold compresses
• Eye drops that contain anti-allergy ingredients
• Washing your face after allergen exposure