Learn about Conjunctivitis symptoms from Consumer Reports Health.

Conjunctivitis

What are the symptoms of conjunctivitis?

Bacterial conjunctivitis usually affects only one eye. Conjunctivitis caused by a virus often affects both eyes, but will start in one eye.

If you have conjunctivitis, your eyes may:

Source:
American Family Physician. November 2002.
Conjunctivitis.
Available at http://www.aafp.org (accessed on 5 November 2008).

Water
Look red
Feel gritty or irritated
Feel as if they are burning or stinging
Feel sore.

If your eyes itch, or you have more than one attack of conjunctivitis in a short space of time, these are signs that your symptoms aren't caused by an infection with

bacteria
Bacteria are tiny organisms. There are lots of different types. Some are harmful and can cause disease. But some bacteria live in your body without causing any harm.

bacteria. You could have an

allergy
If you have an allergy to something, your body overreacts when you're around it. The thing you are allergic to is called an allergen. Most allergens are harmless to most people. But if you're allergic to something, your body's system for fighting infection (your immune system) is too sensitive to that allergen. It triggers changes that we call allergic reactions. For example, pollen is an allergen for many people. If you're allergic to pollen, you'll sneeze and have runny eyes when pollen is in the air.

allergy or an infection caused by a

viruses
Viruses are microbes (tiny organisms) that need the cells of humans or other animals to exist. They use the machinery of cells to reproduce. Then they spread to other cells in the body.

virus. If you get conjunctivitis every year at the same time, it's probably caused by an allergy.

If you also have white or yellow pus coming from your eyes that causes crusts on your eyelids while you sleep, you probably have a bacterial infection.

Source:
Rietveld RP, ter Riet G, Bindels PJ, et al.
Predicting bacterial cause in infectious conjunctivitis: cohort study on informativeness of combinations of signs and symptoms.
BMJ. 2004; 329: 206-210.

Source:
Friedlaender MH.
A review of the causes and treatment of bacterial and allergic conjunctivitis.
Clinical Therapeutics. 1995; 17: 800-810.

Source:
American Academy of Ophthalmology.
Conjunctivitis preferred practice pattern.
Available at http://www.aao.org (accessed on 5 November 2008).

⁴

Some of the symptoms of bacterial conjunctivitis can be similar to the symptoms of more serious eye problems. You should see a doctor right away if:

Source:
American Family Physician. November 2002.
Conjunctivitis.
Available at http://www.aafp.org (accessed on 5 November 2008).

⁵

You have pain inside your eye
There is any sudden change in your vision
Light makes your eyes hurt.

If you wear contact lenses and you get the symptoms of conjunctivitis:

Source:
American Family Physician. November 2002.
Conjunctivitis.
Available at http://www.aafp.org (accessed on 5 November 2008).

Stop wearing your contact lenses
See your doctor.

Conjunctivitis needs to be treated quickly if you wear contact lenses. This is because it can cause a more serious eye infection called keratitis. If you wear contact lenses, it's important to take care of them and clean them properly. This reduces your chance of getting an infection.

If you get conjunctivitis and you wear disposable contact lenses, you should throw away the set of lenses and the lens case you were using. If you keep them you might get the same infection again. If you wear permanent lenses, ask your optician about what to do with them.

You should see a doctor right away if your baby has the symptoms of conjunctivitis. This is because some bacteria that cause conjunctivitis can cause other serious infections in babies.

Sources for the information on this page:

American Family Physician. November 2002.Conjunctivitis.Available at http://www.aafp.org (accessed on 5 November 2008).

Rietveld RP, ter Riet G, Bindels PJ, et al.Predicting bacterial cause in infectious conjunctivitis: cohort study on informativeness of combinations of signs and symptoms.BMJ. 2004; 329: 206-210.

Friedlaender MH.A review of the causes and treatment of bacterial and allergic conjunctivitis.Clinical Therapeutics. 1995; 17: 800-810.

American Academy of Ophthalmology.Conjunctivitis preferred practice pattern.Available at http://www.aao.org (accessed on 5 November 2008).

American Family Physician. November 2002.Conjunctivitis.Available at http://www.aafp.org (accessed on 5 November 2008).

This information was last updated on Apr 24, 2009

This information is for educational use only, and is not a substitute for prompt professional medical advice. Readers should always consult a physician or other professional for advice and treatment.
© BMJ Publishing Group Limited 2009. All rights reserved.

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