If you notice you or your child have a red, irritated eye, you’ll probably question whether it’s pink eye or allergies. Knowing how to tell if red eyes are allergies or an infection is key to getting relief.
“Both conditions can make the eyes look red and watery but they have different causes,” said Linda Stanek, MD, a family medicine specialist with Banner Health.
Here are some ways you can tell whether you’re dealing with pink eye or allergies, what causes these conditions and how to treat them.
What is pink eye?
Infectious pink eye (conjunctivitis) happens when the conjunctiva (the thin tissue that covers the white part of the eye and inside of the eyelid) becomes irritated or inflamed. Viruses and bacteria can cause pink eye. It’s contagious and spreads easily from person to person at home, school or daycare.
What is allergic conjunctivitis?
Allergic conjunctivitis is one of the most common eye allergies. It can happen when your immune system reacts to an allergen like pollen, dust, pet dander or mold. It often occurs with other allergy symptoms, such as sneezing and an itchy or runny nose. It’s sometimes called allergic pink eye but it’s not contagious.
Allergic conjunctivitis vs. pink eye: Key differences
- One vs. two eyes: Infectious pink eye may start in one eye and then spread to the other. Allergies often affect both eyes at the same time.
- Causes: Allergies often happen after you’re exposed to pollen, pets, dust or mold. Viral pink eye may happen with or after a cold.
- Type of discharge: Allergies and viral pink eye usually cause clear, watery tears. Bacterial pink eye symptoms may include thicker yellow or green discharge, crusting or sticky lashes, especially when you wake up.
- Itching vs. irritation: “The biggest clue is itching. People with allergic conjunctivitis often say their eyes are extremely itchy,” Dr. Stanek said.
With infectious pink eye, your eye may feel burning, gritty, irritated or uncomfortable.
Signs it is more likely allergies
- Both eyes are itchy
- Tears are clear and watery, not thick, yellow or green
- Symptoms happen during allergy season or after exposure to dust, pets, pollen or mold
- You also have sneezing and/or a runny or itchy nose
- You have a history of seasonal allergies, asthma or eczema
- Symptoms get better when you treat allergies or avoid triggers
- You don’t have severe pain
Signs it is more likely infectious pink eye
- Symptoms start in one eye
- You have thick yellow or green discharge
- Your eyelids are stuck shut in the morning
- Your eye feels gritty, burning or irritated
- Symptoms start after a cold
- Someone close to you recently had contagious pink eye
How treatment differs
It’s important to get the right diagnosis, because treatment depends on the cause:
- Allergic conjunctivitis: Avoiding triggers and using artificial tears, cool compresses and antihistamine or allergy drops may help.
- Viral conjunctivitis: Artificial tears and cool compresses can reduce symptoms while you heal. If the diagnosis isn’t clear or you’re at higher risk for a bacterial infection, your provider may prescribe antibiotic eye drops or ointment.
- Bacterial conjunctivitis: Prescription antibiotic drops may help in some cases. Do not use leftover antibiotic drops.
“No single symptom can reliably tell viral from bacterial conjunctivitis, so health care providers consider the history, symptoms and exam findings,” Dr. Stanek said. Most cases of pink eye in adults are viral.
Another eye condition could also be causing your symptoms, including glaucoma, corneal ulcers, iritis and herpes eye infections.
What to avoid when your eyes are red or itchy
- Do not rub your eyes.
- Do not share towels, washcloths, pillowcases, eye makeup, eye drops or contact lenses.
- Do not use leftover antibiotic drops.
- Avoid “redness relief” drops as the main treatment, unless a provider recommends them.
- Avoid home remedies such as tea bags, essential oils or breast milk in the eye.
- Do not wear contact lenses until an eye care provider says it’s safe to use them again. You may need to replace your lenses and case.
- Ask your provider if you need to replace your eye makeup.
Wash your hands often and clean commonly touched surfaces if you suspect infectious pink eye. Good hygiene can help keep it from spreading to other people.
When to see a health care provider
Get care for:
- Thick yellow or green discharge
- Moderate to severe eye pain
- Sensitivity to light
- Blurry vision or vision changes
- Symptoms that last more than a few days or get worse
- Symptoms in infants or newborns
- Eye injury or chemical exposure
- A weakened immune system
- Redness around the eye or swelling that is worsening
- Fever or feeling very ill
If you wear contact lenses, you’re at higher risk for a more serious infection of the cornea. Get care right away if you have pain, light sensitivity or vision changes.
Bottom line
Red, itchy or watery eyes can come from allergies, infection or irritation. Allergies often cause intense itching, clear tears and symptoms in both eyes. Infectious pink eye may start in one eye and cause grittiness, discomfort, crusting or thicker discharge.
Treatment depends on the cause. Get checked if symptoms are painful, getting worse, affecting your vision or happening in an infant or contact lens user.
If you are not sure what’s causing red, itchy or watery eyes, a Banner Health provider can review your symptoms and recommend the right next steps.
FAQs about pink eye and allergies
How can I tell if it is pink eye or allergies?
Allergies usually cause intense itching, clear tears and symptoms in both eyes. Infectious pink eye may start in one eye and cause burning, gritty feeling, crusting or thick discharge.
Is allergic pink eye contagious?
No. Allergic conjunctivitis is caused by an allergy trigger and is not contagious.
Is pink eye always contagious?
No. Viral and bacterial pink eye can be contagious but allergic pink eye and irritation-related conjunctivitis are not contagious.
What color is pink eye discharge?
Allergies and viral pink eye often cause watery discharge. Bacterial pink eye may cause thicker yellow or green discharge.
Can I use leftover antibiotic eye drops?
No. Do not use leftover antibiotic drops. The wrong treatment may not help and could cause irritation or other problems.
When should I worry about red eyes?
Get care for eye pain, light sensitivity, vision changes, thick discharge, worsening symptoms, contact lens use or symptoms in infants.
