What is pink eye?

Pink eye, or conjunctivitis, causes swelling and redness in the inside of your eyelid and the white part of your eye. Your eye may also feel itchy and painful.

What causes pink eye?

Most of the time, pink eye is caused by an infection — a virus or bacteria. Viral pink eye is the most common type. Pink eye that’s caused by an infection can spread very easily, so avoid passing it to others by washing your hands often and not sharing items like pillowcases, towels, or makeup.

You can also get pink eye from an allergy or eye irritation.

Take these steps to prevent pink eye:

  • Wash your hands often if you’re around someone who has pink eye
  • Don’t share personal items with someone who has pink eye
  • Change your contact lenses as often as your eye doctor recommends
  • Clean your glasses regularly
  • Throw out old makeup and makeup brushes

What germs cause pink eye infections?

Viral pink eye is most often caused by a common virus called adenovirus, but other viruses can also cause pink eye. If you have viral pink eye, you may also have a cold or sore throat.

Bacterial pink eye can be caused by many different types of bacteria. Some common types are Staphylococcus aureus, Streptococcus pneumoniae, or Haemophilus influenzae.

It’s also possible to get pink eye from a fungus or parasite, but it’s not common.

What allergens cause pink eye?

You can get pink eye if something you’re allergic to gets in your eye. Common allergens are:

  • Pollen
  • Dust mites
  • Molds
  • Animal dander (flakes of skin)

This kind of pink eye is not contagious, meaning you can’t pass it to someone else. You’re more likely to get this kind of pink eye if you have allergies to many different things. To help prevent allergic pink eye, ask your doctor about ways to treat your allergies.

What irritants cause pink eye?

You can get pink eye if something gets in your eye that irritates it. Some common irritants are:

  • Contact lenses
  • Contact lens solution
  • Chlorine in a swimming pool
  • Cosmetics (makeup)
  • Dust

This kind of pink eye is not contagious, meaning you can’t pass it to someone else. Pink eye from irritation is usually mild and goes away on its own.

Who is at risk for pink eye?

Anyone can get pink eye, but you may be more likely to get it if you:

  • Have had close contact with someone who has pink eye
  • Wear contact lenses
  • Are allergic to things like pollen, animal dander, or mold

Newborn babies are also at risk for pink eye. Newborns can get pink eye from bacteria or irritating chemicals that get into their eyes during or after birth.

Remember, pink eye infections can spread very easily, so avoid close contact with other people if you have it.

Last updated: July 8, 2019