Conjunctivitis, commonly known as “pink eye,” is an infection or swelling in your conjunctiva, which is a thin, transparent membrane that lies over the inner surface of the eyelid and covers the white part of your eye.

When you have pink eye, blood vessels in your conjunctiva become inflamed. This gives your eye the red or pink color that’s commonly associated with conjunctivitis.

There are a few different types of pink eye that come with varying symptoms and treatments.

Different types of pink eye can come with slightly different symptoms, but in general, it’s important to talk with a doctor if you start to experience:

  • pink or red-toned eyes
  • a gritty feeling in your eyes
  • watery or thick discharge that builds up on your eyes at night
  • itchiness in your eyes
  • abnormal amount of tears

In general, there are three main categories of pink eye:

  • infectious
  • allergic
  • chemical

Infectious conjunctivitis

Infectious pink eye comes in a few different types, including:

  • bacterial
  • viral

Bacterial pink eye is caused by staphylococcal or streptococcal bacteria. It typically occurs due to things like touching your eyes with unclean hands, sharing makeup, or having physical contact with someone who may also have conjunctivitis.

Viral pink eye is usually caused by common cold viruses. It can occur if someone with an upper respiratory infection coughs or sneezes close to you. It can also occur when you have a cold virus yourself and blow your nose too hard. This can push the infection from your respiratory system to your eyes.

Allergic conjunctivitis

Most people with allergic pink eye have seasonal allergies. They can get pink eye if they come in contact with a substance they’re allergic to, like pollen.

It’s also possible to develop an allergic type of pink eye called giant papillary conjunctivitis if you wear hard contact lenses, or soft contact lenses that aren’t replaced frequently enough.

Chemical conjunctivitis

You can get pink eye from irritants such as:

  • chlorine in pools
  • air pollution
  • exposure to other chemicals

Bacterial and viral pink eye are very contagious.

Pink eye is very easily spread from person to person. For instance, if someone with viral pink eye touches their eye and then touches your hand, and you touch your eyes, there’s a chance you could get pink eye as well.

Pink eye is typically contagious for as long as the person is having symptoms.

It’s typically not difficult for a healthcare professional to diagnose pink eye. They will usually be able to tell if you have pink eye simply by asking you a few questions and looking at your eyes.

For example, a healthcare professional might ask you if your eyes are itchy and whether you have watery or thick discharge. They might also ask if you’re experiencing symptoms of a common cold, hay fever, or asthma.

They may also perform a few tests, including:

  • a vision test to see whether your vision has been affected
  • external eye tissue examination, including the conjunctiva, using bright light and magnification
  • examination of the inner eye to make sure no other tissues have been affected
  • conjunctival tissue smear, which is typically done when a person is dealing with chronic pink eye, or the condition is not improving with treatment

Treatment of conjunctivitis depends on what’s causing it.

Chemical conjunctivitis

Rinsing your eye with saline is one way to help ease symptoms if you’re dealing with chemical pink eye. Topical steroids may also be prescribed if the case is severe enough.

Bacterial conjunctivitis

For a bacterial infection, antibiotics are the most common method of treatment. Adults usually prefer eye drops. For children, ointment might be a better choice because it’s easier to apply.

With the use of antibiotic medication, your symptoms will probably start to disappear in just a few days — but it’s important to finish your entire prescription to lessen the risk of pink eye coming back.

Viral conjunctivitis

Most of the time, viral conjunctivitis is caused by the same viruses that cause the common cold. These cold viruses don’t currently have any treatments, but symptoms are usually mild and resolve on their own in 7 to 10 days.

In rare cases, other viruses like the herpes simplex or varicella-zoster virus can be involved, which can cause more serious infections. These viruses do have antiviral treatments, but these treatments can only be used for these specific types of viral infections.

In the meantime, using a warm compress, or a cloth moistened with warm water, can help soothe your symptoms.

Allergic conjunctivitis

To treat pink eye caused by an allergen, your healthcare professional will probably prescribe an antihistamine to stop the inflammation.

Loratadine (Claritin) and diphenhydramine (Benadryl) are antihistamines that are available as over-the-counter medications. They may help clear your allergic symptoms, including allergic pink eye.

Other treatments include antihistamine eye drops or anti-inflammatory eye drops.

Home remedies

In addition to using a warm compress, you can also purchase eye drops at your local drugstore that mimic your own tears. These may help relieve your pink eye symptoms.

It’s also a good idea to stop wearing contact lenses until your pink eye completely clears up.

Practicing good hygiene is one of the best ways to avoid and stop the transmission of conjunctivitis:

  • Avoid touching your eyes with unwashed hands whenever possible.
  • Wash your hands often and thoroughly with soap and water.
  • Only use clean tissues and towels to wipe your face and eyes.
  • Try not to share cosmetics, especially eyeliner or mascara, with others.
  • Wash pillowcases frequently.

If your healthcare professional thinks your contact lenses are contributing to your pink eye, they may recommend switching to another type of contact lens or disinfectant solution.

They may also suggest cleaning or replacing your contact lenses more frequently, or that you stop wearing contact lenses indefinitely (or at least until your eye heals).

Avoiding poorly fitted contact lenses and decorative contact lenses may also decrease your risk for pink eye.

Preventing the transmission of pink eye

If you already have pink eye, you can help keep your friends and family safe by doing the following:

  • Wash your hands regularly.
  • Avoid sharing towels or washcloths.
  • Change your towel and washcloth daily.
  • Replace eye cosmetics after your infection clears.
  • Follow your healthcare professional’s advice on contact lens care.
  • Take any medication your doctor has given you as prescribed.

If your child has pink eye, it’s a good idea to keep them out of school for at least 24 hours after they start treatment to keep them from transmitting pink eye to others.