Pink eye is an eye infection that may occur due to a virus, bacteria, or allergen. Viral and bacterial pink eye are highly contagious. While the two conditions may look similar, their causes and how long they last will be different.

Pink eye is an infection that causes your eyes to become itchy and swollen. It’s also called conjunctivitis. Not all types of pink eye are contagious. When the condition occurs from a bacteria or a virus, you can spread it to someone else.

Bacterial and viral pink eye share similar symptoms, but there are some unique signs of each type. If your conjunctivitis is severe, you might need to speak with a doctor.

Pink eye has several potential causes, including allergens, irritants, chemicals, and foreign bodies in the eye. When pink eye results from one of these causes, the condition is not contagious, meaning it won’t spread from person to person. But bacteria and viruses can also lead to pink eye, and these types are both contagious.

Viral pink eye causes

If you have a cold or upper respiratory infection, you could also develop viral pink eye, but that isn’t always the case. Several viruses can lead to conjunctivitis, such as:

Adenoviruses cause up to 90% of viral conjunctivitis cases. You can get a virus that causes pink eye through airborne transmission, by coming into direct contact with the virus, or by swimming in pools or other bodies of water that contain the virus.

Bacterial pink eye causes

You can get bacterial pink eye through hand-to-eye contact or by spreading respiratory droplets from person to person. Some of the more common types of bacteria to cause pink eye are:

The most common bacterial causes are a bit different between adults and children. Most cases of bacterial conjunctivitis in adults are from the Staphylococcus family of bacteria, while for children it’s most commonly Haemophilus influenzae.

There are some common symptoms that both viral and bacterial pink eye share. There are also additional symptoms unique to each cause.

Common symptoms of viral and bacterial pink eye include:

  • the whites of the eyes appearing red or pink
  • swelling of the eyelids
  • crusty eyelids or eyelashes
  • tearing or watering of the eyes
  • discharge from the eye
  • itchiness or burning of the eye
  • eye irritation
  • feeling like something is in your eye
  • discomfort with contact lenses or ill-fitting lenses

Additional symptoms include the following:

  • Viral conjunctivitis usually causes watery discharge and starts in one eye and moves to the other eye.
  • Bacterial conjunctivitis usually causes a thick discharge of pus.

If you have a bacterial form of pink eye, your eyelids might stick together due to the discharge.

Bacterial pink eye sometimes develops when you get an ear infection. Viral pink eye can occur when you’re dealing with another illness caused by a virus, such as a cold, flu, or upper respiratory tract infection.

If you’ve been in close contact with a person who has conjunctivitis, you’re more likely to get it, whether their infection was viral or bacterial.

Most cases of bacterial pink eye are from bacteria that’s already on your skin or in your respiratory system. Some actions can increase the risk of bacterial conjunctivitis, such as:

  • not washing hands before touching the eyes
  • using contaminated eye makeup or face creams
  • sharing makeup
  • not cleaning contact lenses before wearing them

Risk factors for viral pink eye include:

  • being around someone who coughs or sneezes while having a respiratory infection

You don’t always have to consult a doctor for pink eye. Both viral and bacterial conjunctivitis should get better on their own. If pink eye is severe, you should consider speaking with a doctor.

According to the National Eye Institute, viral pink eye can take up to 3 weeks to completely clear up, but it usually resolves in a week or 2 without treatment. Bacterial pink eye usually gets better within 2 to 5 days, but it might take more than 2 weeks to go away without treatment.

A doctor might prescribe antibiotics to treat bacterial pink eye, but it isn’t always necessary. Antibiotics can make the infection clear up more quickly.

Home treatment

Artificial tears, which are eye drops you can buy over the counter, can help relieve dryness. Keeping the artificial tears cold in the refrigerator can also be soothing. A cold compress placed over your eyes several times per day can help relieve the discomfort of swelling and reduce redness.

When to see a doctor

You should consider speaking with a doctor if you have signs of a severe infection or if you have certain medical conditions.

Symptoms of severe infection include:

  • moderate to severe eye pain
  • vision changes such as blurriness
  • light sensitivity
  • intense redness in the eyes
  • excessive mucus during the day or upon waking
  • no symptom relief from artificial tears or cold compresses

Medical conditions include:

  • human immunodeficiency virus (HIV)
  • cancer (and its treatments)
  • any other condition that weakens the immune system

Although pink eye doesn’t have any serious complications, it can spread easily between people. This can cause symptoms among all family members, roommates, and others if a person doesn’t take preventive action.

An individual with pink eye should try to take steps to avoid spreading it. You can reduce transmission while you have the infection by:

  • frequently washing your hands
  • not sharing makeup, towels, or linens
  • throwing out eye cosmetics like mascara
  • discarding tissues after use on your face or eyes
  • practicing good contact lens hygiene

Which is worse, viral or bacterial pink eye?

Viral pink eye can last longer than bacterial pink eye. However, bacterial pink eye can cause thicker discharge from the eyes, which might make your eyelids stick together.

How long is pink eye contagious for?

Both types of pink eye are contagious as long as there is discharge from the eye or an excessive amount of tears.

Is it OK to leave pink eye untreated?

Pink eye usually resolves on its own without treatment within a week or 2. However, it’s a good idea to speak with a doctor if you have severe symptoms or live with a weakened immune system.

Bacterial and viral pink eye are highly contagious eye infections. You can limit the spread by washing your hands frequently and not sharing makeup, towels, or linens.

Conjunctivitis usually gets better on its own, but a doctor might prescribe antibiotics in some cases of bacterial pink eye. You can soothe symptoms with artificial tears and cool compresses.