Can allergies cause red eyes?
Yes. Pink or red eyes are the most common eye allergy symptom, which occurs when the small blood vessels widen. Typical allergens affecting the eyes include pollen and mold spores, animal dander and dust mites.1
How allergies cause it
Redness is the most common eye allergy symptom: the small blood vessels widen and the eyes become pink or red.1 Symptoms usually appear quickly, soon after the eyes come in contact with the allergen.1
An allergic reaction in the eyes can occur when an allergen comes in contact with antibodies attached to the mast cells in your eyes.2 The cells respond by releasing histamine and other substances or chemicals that cause tiny blood vessels to leak and the eyes to become itchy, red and watery.2 Other symptoms include swollen eyelids, a burning sensation and sore or tender eyes.1
Eye allergy triggers include outdoor allergens, such as pollens from grass, trees and weeds; indoor allergens, such as pet dander, dust mites and mold; and irritants, such as cigarette smoke, perfume and diesel exhaust.2 Seasonal allergic conjunctivitis is by far the most common type of eye allergy, with symptoms in spring, summer or fall, depending on the type of plant pollens in the air.2 A year-round form, with symptoms that tend to be milder, is caused by reactions to dust mites, mold, pet dander or other household allergens.2
Most people with eye allergies have problems in both eyes.1
Allergies or something else?
A common sign of pink eye is pink or red color in the white of the eye from visible blood vessels.4 With allergic pink eye, both eyes are usually involved and intense itching can occur.4 Viral pink eye can occur with a cold, flu or respiratory infection, usually begins in one eye and spreads to the other within days, and its discharge is usually watery, not thick.4 Bacterial pink eye usually brings thick pus, which can make the eyelids stick together.4 Pink eye from an infection is easily passed from person to person; eye allergies are not contagious.3
When to see a doctor
Pink eye can also affect vision.4 CDC advises seeing a healthcare provider if you have eye pain, light sensitivity, blurred vision or intense eye redness.4
If eye allergy symptoms persist, ACAAI advises seeing an allergist.2
Related conditions
When to get help
See an allergist if
- Allergy symptoms last for several months of the year
- Allergies bring repeated sinus problems, a blocked nose or trouble breathing
- Over-the-counter remedies don’t control your symptoms
- Allergies or asthma get in the way of daily life
- You often wheeze, cough at night or after exercise, or feel short of breath
Based on ACAAI’s “When To See an Allergist”. General information, not medical advice.
Questions
Why do allergies make the whites of my eyes red?
Because small blood vessels widen. In an eye allergy, the most common symptom occurs when the small blood vessels widen and the eyes become pink or red.1
Is it pink eye from an infection or from allergies?
Allergic pink eye usually affects both eyes and can cause intense itching, and other allergy symptoms such as an itchy nose or sneezing may occur. Viral pink eye usually begins in one eye and spreads to the other within days, and bacterial pink eye usually brings thick pus that can make the eyelids stick together.4
Are red eyes from allergies contagious?
No. Eye allergies are not contagious. Pink eye from a viral or bacterial infection is different: it is easily passed from person to person, and it usually starts in one eye and can spread to the other within a day or two.3
When should red eyes from pink eye be checked by a doctor?
When they come with eye pain, light sensitivity, blurred vision or intense eye redness. CDC says pink eye can also affect vision and advises seeing a healthcare provider for any of these.4
Sources
- Common Eye Symptoms Could be an Allergy. American Academy of Allergy, Asthma & Immunology. Read on October 16, 2026.
- Eye Allergy. American College of Allergy, Asthma and Immunology. Read on October 16, 2026.
- Eye Allergy / Allergic Conjunctivitis. Asthma and Allergy Foundation of America. Read on October 16, 2026.
- Symptoms of Pink Eye. Centers for Disease Control and Prevention. Read on October 16, 2026.