Conjunctivitis (Pink Eye)

Commonly known as “pink eye,” conjunctivitis is an irritation or infection of the membrane that covers the white of the eye and the inside lining of the eyelid.


What is conjunctivitis (pink eye)?

Conjunctivitis, also known as pink eye, is an inflammation of the thin, clear tissue that lies over the white part of the eye and lines the inside of the eyelid. It can be highly contagious, often spreading rapidly in schools and daycares, but is rarely serious.

What are the different types of conjunctivitis?

There are four different forms of conjunctivitis — viral conjunctivitis, bacterial conjunctivitis, allergic conjunctivitis, and conjunctivitis resulting from irritation. The most common forms of conjunctivitis are caused by either a viral or bacterial infection. Both types are highly contagious and can spread through direct and indirect contact.

Viral conjunctivitis

  • Viral Conjunctivitis, often characterized by eye redness and a watery discharge, is often accompanied by symptoms such as a cold, sore throat or fever.

Bacterial conjunctivitis

  • Bacterial conjunctivitis, often caused by a staph or strep bacteria, presents itself in the form of eye redness and often a mucus-like discharge.

Allergic conjunctivitis

    Allergic conjunctivitis affects both eyes and is a response to an allergy-causing substance such as pollen.

  • Intense itching, tearing and inflammation of the eyes — as well as sneezing and watery nasal discharge, are all common side-effects of allergic conjunctivitis. However, most cases can be controlled with allergy eye drops.

Conjunctivitis resulting from irritation

    Irritants such as a chemical splash, environmental irritant/foreign body or contact lens are responsible for this form of conjunctivitis.

  • Symptoms vary depending on the cause

When to call the doctor

Conjunctivitis with serious symptoms such as vision loss, pain, suspected foreign body or chemical burn should be seen immediately. If conjunctivitis symptoms are mild but persist for more than 24 hours, make an appointment with your doctor. Contact users should stop wearing lenses as soon as symptoms begin, and carefully monitor their condition to avoid a more serious issue.

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Other conditions that cause eye redness can often be serious and may present a feeling that something is in your eye, blurry vision or light sensitivity. If you’re experiencing any of these issues, seek urgent care immediately.


What causes conjunctivitis (pink eye)?

Conjunctivitis is commonly caused by a viral or bacterial infection, an allergic reaction, or other outside factors. Even though this condition is irritating, the good news is that it rarely affects your vision.

Viral Conjunctivitis

One of the most common forms of pink eye, viral conjunctivitis, is caused by a number of different viruses including the adenovirus—which can present itself in the form of the common cold.

Bacterial Conjunctivitis

A highly contagious form of pink eye, bacterial conjunctivitis is caused by certain bacterias such as staph and strep infections.

Allergic Conjunctivitis

Allergic conjunctivitis is a result of your body’s reaction to allergens such as pollen. It is not contagious and can occur seasonally when pollen counts are high.

Conjunctivitis from Irritation

Conjunctivitis from irritation can occur when a foreign body enters your eye, such as smoke, dust or chemicals. Contact users are more susceptible to this form if lenses are worn longer than recommended or not cleaned properly.


What are the symptoms of conjunctivitis (pink eye)?

Pink eye affects roughly six million people in the U.S. each year, and is one of the most common infections in adults and children. So what are the symptoms?


This is common for pink eye brought on by chemicals or allergens.


Usually appears in one or both eyes and is often caused by allergens.


Is seen in one or both eyes in the white of the eye or corner of the eyelid.

Blurred Vision

Frequently occurs in one or both eyes and is usually a result of allergens or a foreign body.


Excess tear production is a common sign, and may be accompanied by watery eyes or inflammation.


How is conjunctivitis (pink eye) diagnosed?

In most cases, pink eye can be straightforward and diagnosed by history and doctor exam.

In rare cases, your doctor may request lab tests or a culture for high-risk patients and patients who suspect their condition is caused by a foreign body in the eye, a serious bacterial infection, or a sexually transmitted disease.

An eye doctor uses a small tool to examine a young girl's eye.

Treatment & Prevention

How is conjunctivitis (pink eye) treated?

Although pink eye can be a highly contagious and common infection, the good news is it’s totally treatable! Treatment depends on the cause of the conjunctivitis – your doctor may recommend artificial tears, lid hygiene, OTC or Rx eye drops.

How can conjunctivitis be prevented?

Since viral and bacterial pink eye is highly contagious and can easily spread from person to person, it’s important to follow these simple steps to reduce your chances of infection.

Wash your hands

Good hygiene is essential to avoid pink eye, which is why you should wash your hands often with warm water and soap for 20 seconds.

Avoid eye touching

Avoid touching or rubbing your eyes, as bacteria can easily jump from one eye to the other.

Do not share products

Do not share personal products such as makeup, eyedrops, towels and eyeglasses. This reduces your risk of getting pink eye from a person who may be infected.

Clean contact lenses

Clean, store, and replace your contact lenses as instructed by your eye doctor to avoid pink eye and other serious infections.

Think you may have conjunctivitis?