Bacterial Conjunctivitis (Pink Eye)

What is bacterial conjunctivitis?

Bacterial (bak·tee·ree·uhl) conjunctivitis (kuhn·juhngk·tuh·vai·tuhs) is an infection of the eye caused by bacteria. Conjunctivitis, or pink eye, is inflammation of the conjunctiva. The conjunctiva is a thin, clear membrane that covers the white part of the eyeball (the sclera) and the inside of the eyelid. A virus, allergies, and chemical irritants can also cause conjunctivitis.

Anatomy of the human eye relevant to viral conjunctivitis (pink eye), emphasizing areas such as eyelid, sclera, cornea and conjunctiva.

Anatomy of the human eye, showing the conjunctiva

What causes bacterial conjunctivitis?

Bacterial conjunctivitis is usually caused by staphylococcus (sta·fuh·luh·kaa·kuhs), streptococcus (strep·tuh·kaa·kuhs ) , or other common bacteria that live on your skin and in your airway. It is highly contagious and can spread when you come into contact with someone who has an eye infection, and you touch your face or eyes without washing your hands. Conjunctivitis can also spread by respiratory droplets or by sharing cosmetics and linens with a person who has conjunctivitis.

What are the symptoms of bacterial conjunctivitis?

Bacterial conjunctivitis often starts in one eye and spreads to the other. It often develops quickly, over a few days.

Symptoms of bacterial conjunctivitis can include.

  • Red eyes
  • Thick, pus-like eye discharge, which is often yellow or green
  • Crusting or stickiness of the eyelids and eyelashes
  • Swollen eyelids

Bacterial pink eye symptoms can be mild or severe, depending on the type of bacteria involved and the health of the infected person. Most people with bacterial conjunctivitis do not have pain or vision changes. Discharge and watering may cause temporary blurry vision. Contact Lens wearers are at greater risk of bacterial conjunctivitis with potential for serious complications.

An illustration of an eye showing typical symptoms of bacterial conjunctivitis (bacterial pink eye) including redness.An illustration of an eye affected by bacterial conjunctivitis (bacterial pink eye), showing redness and watery eyes

Preventing the spread of bacterial conjunctivitis

If you have bacterial conjunctivitis and want to prevent spreading it to others, try to limit interactions with other people.

How is bacterial conjunctivitis diagnosed?

It is not necessary to visit your eye doctor at the first symptoms of eye irritation.

You should make an appointment with your eye doctor or primary care provider if you have any of the following:

  • Symptoms continue or worsen over 24 hours
  • Wear contact lenses and have a red eye for more than one day
  • Have a significant change in your vision
  • Experience any eye pain

Your doctor can diagnose bacterial conjunctivitis based on your symptoms and through an eye exam.

During the exam, the doctor will:

  • Take your health history
  • Check your visual acuity (test how well you can see through your central vision in each eye with an eye chart)
  • Examine the front of your eye (including your cornea)

The doctor will determine the best treatment for you.

How is bacterial conjunctivitis treated?

Bacterial conjunctivitis often goes away on its own, without treatment, in about ten days.

To help the symptoms, you can:

  • Use warm or cool compresses to relieve discomfort
  • Use artificial tear eye drops and over-the-counter anti-inflammatories (like ibuprofen) to help with discomfort
  • Avoid the use of eye drops that reduce redness (it can make redness worse afterwards)
  • Not wear contact lenses until the infection is gone

If you have bacterial pink eye, your doctor may prescribe antibiotic eye drops or ointment. This medicine can only treat conjunctivitis caused by bacteria. It will not help with viral or allergic conjunctivitis. Antibiotic eye drops may have side effects. They can cause discomfort or allergic reactions, and they often contain preservatives that can irritate your eye. Note, using the wrong over the counter medicine could cause more harm to your vision. Talk with your eye doctor about any medications before use.

How can you prevent bacterial conjunctivitis?

Bacterial conjunctivitis can spread easily. You can prevent spreading it to your other eye and other people.

The best way to prevent bacterial conjunctivitis is to practice good hygiene:

  • Do not touch or rub the infected eye
  • Wash your hands often with soap and water
  • Use paper towels or tissues instead of cloth towels
  • Do not share towels or pillows
  • Wipe any discharge from eyes
  • Wash any cloth towels, washcloths, and linens in a hot water laundry cycle
  • Do not use contact lenses or eye makeup until your eye is healed
  • Throw away old cosmetics, especially mascara
  • If you wear contacts, replace your lens case with a new one
  • If you wear contacts, throw away the current pair and use a new pair once your infection has healed

Questions to ask your doctor

  • What is causing my conjunctivitis?
  • What can I do to treat it?
  • How will I know if my condition is getting worse?
  • How long will it take for my eye to get better?
  • How can I prevent spreading it to others?
  • Do I need to stay home from work or school?
  • Will this condition cause any permanent damage to my eye?
  • Do I need to come back for a follow-up visit?

Resources

Tips and a how to video for taking eye drop medications

a woman taking eye drop medicine