What Is Pink Eye (Conjunctivitis)? Symptoms, Causes, Diagnosis, Treatment, and Prevention

Medically Reviewed
Pink eye — also known as conjunctivitis — is an inflammation of the conjunctiva, the thin, transparent membrane that covers the white part of the eye (sclera) and the inner surface of your eyelids, according to Mayo Clinic.

Some forms of conjunctivitis are infectious and can spread very quickly, a fact that’s given pink eye a notorious reputation. Pink eye is most commonly associated with itching and burning in the eyes, discharge, and pink or red discoloration to the whites of the eyes. Pink eye often starts in one eye and then spreads to the other one, according to the National Eye Institute.

Pink eye is a very common eye problem, especially in children. But with proper management, it rarely causes long-term vision damage.

Common Questions & Answers

What causes pinkeye?
Pinkeye is most commonly caused by a bacterial or viral infection, but it can also be triggered by allergies or exposure to irritants such as air pollution, smoke, and cosmetics.
How is pinkeye spread?
Pinkeye is spread by hand-to-eye contact, or if the eye comes in contact with a contaminated object. Viral and bacterial conjunctivitis can be spread through the air by coughing and sneezing.
Are there different types of pinkeye?
There are several types, including infectious conjunctivitis, allergic conjunctivitis, irritant or chemical conjunctivitis, and ophthalmia neonatorum.
What are common symptoms of pinkeye?
Symptoms of pinkeye may include pink or red discoloration in the white of the eye, eye pain or itching, gritty or watery discharge, or sensitivity to bright light.
Is pinkeye related to other conditions?
Conjunctivitis has been associated with certain conditions, including psoriatic disease, the removal of enlarged adenoids, and sexually transmitted diseases.

Signs and Symptoms of Pink Eye

Symptoms of pink eye can vary from person to person and depending on the type of conjunctivitis involved. According to the Centers for Disease Control and Prevention (CDC), in general, symptoms may include:

  • Pink or red discoloration in the white of one or both eyes
  • Pain in one or both eyes that can include itching, burning, or a gritty feeling
  • Watery or gritty discharge from one or both eyes that may cause your eyelids to be stuck together when you wake up in the morning
  • Swollen eyelids
  • Excessive tearing
  • Sensitivity to bright light

Causes and Risk Factors of Pink Eye

The condition is commonly caused by viral or bacterial infections or an allergic reaction. Exposure to irritants such as air pollution, smoke, and cosmetics can also trigger it. And in babies, an incompletely open tear duct can cause pink eye.

Less commonly, conjunctivitis can be caused by sexually transmitted infections like gonorrhea and chlamydia, notes the Merck Manual.

Pink eye is spread by hand-to-eye contact or if the eye comes in contact with contaminated objects. Viral and bacterial conjunctivitis can also be spread through the air by coughing and sneezing, according to the CDC.

There are several types of conjunctivitis, each with a different cause. These include:

Infectious Conjunctivitis

This type is caused by a bacterial or, more commonly, viral infection. It spreads rapidly from person to person.

Viral conjunctivitis is most often caused by adenovirus, a virus associated with respiratory diseases and the common cold. It can be the result of exposure to the coughing or sneezing of someone with an upper-respiratory-tract infection, and it can develop as a virus spreads through a person’s body.

In addition to other viral infections (from the common cold to measles), COVID-19 has also been associated with conjunctivitis in children — though the data is still preliminary, according to the Cleveland Clinic.

Staphylococcal or streptococcal bacteria usually cause bacterial conjunctivitis. Infection can be spread through person-to-person contact, hand-to-eye contact, or eye contact with a contaminated object such as makeup or contact lenses.

Allergic Conjunctivitis

This type tends to happen in people who normally get allergies and occurs when the eyes are exposed to a trigger or allergen that causes an allergic reaction.

The most common form of allergic conjunctivitis is seasonal. It’s triggered by mold spores or pollen from flowering trees, grass, and weeds.

The year-round form of allergic conjunctivitis is usually caused by allergens such as animal hair or dander, feathers, and dust mites, according to the CDC.


Irritant or Chemical Conjunctivitis

This type of pink eye is brought on by environmental factors that irritate the eyes. These can include smoke, car exhaust, air pollution, soap, cleaning products, hair spray, makeup, and the chlorine found in swimming pool water, notes the Cleveland Clinic.

Ophthalmia Neonatorum

This severe form of bacterial conjunctivitis occurs in newborn babies. It’s caused by exposure to gonorrhea and chlamydia in the birth canal.

How Is Pink Eye Diagnosed?

A doctor or eye care professional can usually diagnose conjunctivitis — and which type you have — through an eye exam.

During an exam, your doctor may ask if you have experienced symptoms such as:

  • Itching
  • Pain
  • Discharge from the eye
  • Blurred vision
  • Runny nose
  • Fever
  • Sore throat
Bacterial conjunctivitis is more commonly associated with a thick, sticky, yellow-green discharge — from the eyelids and corners of the eyes — that lasts all day, according to the American Optometric Association (AOA).

Viral conjunctivitis may also produce discharge but it’s usually watery.

And viral conjunctivitis is often accompanied by other symptoms such as a cold, flu, or sore throat, notes the AOA.

Pink eye is not typically serious and usually clears up on its own, but the CDC recommends seeing a healthcare provider if you have signs of conjunctivitis along with any of the following:

  • Moderate to severe eye pain
  • Intense redness in the eye
  • Sensitivity to light or blurred vision, even once any discharge is wiped away
  • A weakened immune system, such as from HIV or cancer treatment

Is It Conjunctivitis or Something Else?

Many of the symptoms associated with pink eye overlap with other eye conditions.

A pink or red discoloration of the white of the eye, for instance, can be the sign of a serious inflammatory condition, such as scleritis or uveitis. Scleritis is an inflammation of the outer protective barrier around the eye. Uveitis is an inflammation and swelling of the middle coating of the eyeball, according to an article published in April 2017 in The Western Journal of Emergency Medicine.

Discharge from conjunctivitis can temporarily affect your eyesight, but blurred vision may also signal other eye problems such as glaucoma, a torn retina, or age-related macular degeneration, according to the Merck Manual.

Getting your eyes checked and being properly diagnosed is the key to getting the treatment that you need as soon as possible.

Duration of Pink Eye

If it’s due to a viral infection, the pink eye will usually get better on its own within two weeks. Pink eye caused by a bacterial infection will usually get better within a week, though it can take over two weeks to go away completely, notes the NEI.

?Antibiotics are generally not needed says the AOA,

and should be reserved for situations where it’s necessary for an adult or child to return to work or school imminently. Allergic conjunctivitis usually improves quickly after removing the offending allergen from the person’s environment.
If conjunctivitis lasts for more than four weeks, it’s considered chronic, notes the Johns Hopkins Medicine Wilmer Eye Institute.

Treatment and Medication Options for Pink Eye

The treatment you need for conjunctivitis depends on what caused it.

Treatment for Bacterial Conjunctivitis

Bacterial conjunctivitis often goes away on its own and antibiotics are not necessary. But for those with severe symptoms, a weakened immune system, or a persistent infection that doesn’t resolve in a week, this type of infection is treated using antibiotic eye drops or ointments.

You should see improvement within a week.

Treatment for Viral Conjunctivitis

No treatment exists for the viral infection. It will have to run its course, which can take about two to three weeks.

Cool or warm compresses can help your eyes feel better. Artificial tears and antihistamine eye drops also can help ease symptoms.

In more severe cases, a doctor may prescribe steroid drops for the inflammation, though this won’t shorten the duration of the virus.

Treatment for Allergic Conjunctivitis

As with any allergic reaction, removal and avoidance of allergens is the first step in treatment.

This type of inflammation can be treated using anti-allergy medications and nonsteroidal anti-inflammatory drugs (NSAIDs) such as aspirin and Advil or Motrin (ibuprofen). Topical steroid drops may also be prescribed.

Treatment for Irritant Conjunctivitis

Treatment may involve a series of careful eyewashes and flushing of the eyes with saline. Steroid eye drops may be prescribed. Chemical injuries, such as alkali burns, can cause eye damage and require immediate medical attention.

Are There Home Remedies for Pink Eye?

There’s no substitute for having a doctor examine your eyes regularly, especially if you’re experiencing any persistent or serious symptoms. But there are things you can do at home do to ease the discomfort associated with pink eye (depending on the type of infection you have).

These include:

Eyedrops?Over-the-counter lubricant drops known as artificial tears are often used to soothe eye irritation and redness. They can also help with the dryness that can be caused by chronic conjunctivitis. If your conjunctivitis is related to allergies, antihistamine eye drops can reduce itching or redness and relieve watery eyes.

Hot or Cold Compresses?According to the AOA, applying compresses to the affected eye or eyes can help relieve discomfort from viral or bacterial conjunctivitis. Warm compresses can help loosen and remove discharge and make the eye feel better. Cool compresses can relieve itch and calm inflammation. For allergic conjunctivitis, the AOA recommends cool compresses. If only one eye is infected, make sure not to touch the other eye with the same compress.

Prevention of Pink Eye

To prevent allergic or irritant pink eye, you'll need to figure out what is triggering the conjunctivitis, and either remove it or avoid it.

When it comes to infectious pink eye, prevention may not always be possible but you can reduce your risk of catching conjunctivitis by following these steps:

  • Wash your hands regularly and thoroughly.
  • Avoid hand-to-eye contact.
  • Change your pillowcases often.
  • Wash linens and towels in hot water and detergent.
  • Never share eye cosmetics or personal eye-care items.
  • Never use the same eye-drop dispenser for an infected and a noninfected eye.
  • Keep eyeglasses clean.
If you have conjunctivitis, you can prevent spreading it by taking these steps the CDC recommends:

  • Wash your hands often with soap and warm water and wash them especially after cleaning, or applying eye drops or ointment to, your infected eye.
  • Avoid touching your eyes.
  • Wash discharge from around your eyes a few times a day using a clean, wet washcloth or fresh cotton ball. Dispose of the cotton balls and wash used washcloths with hot water and detergent. Make sure to then wash your hands again with soap and warm water.
  • Don’t use the same eye drop dispenser or bottle for your infected and noninfected eyes.
  • Wash linens and towels often in hot water and detergent.
  • Don’t wear contacts lenses until your eye doctor gives you the okay.
  • Clean your glasses.
  • Don’t share pillows, washcloths, towels, eye drops, eye or face makeup, makeup brushes, contact lenses, or glasses.
  • Don’t use swimming pools.
If you’ve recovered from conjunctivitis, avoid becoming reinfected by doing the following:

  • Dispose of any makeup used while your eyes were infected.
  • Get rid of disposable contact lenses and lens solutions that you used when you had pink eye.
  • Clean extended-wear contact lenses and eyeglasses that you used while you were infected.

Complications of Pink Eye

Long-term complications from pink eye are uncommon, but on rare occasions, the cornea can become infected, leading to permanent vision damage, according to Johns Hopkins Medicine.

Newborns have a higher risk of complications. For babies with neonatal infective conjunctivitis, complications may include meningitis and infection of the bloodstream, notes the CDC.

But with treatment, the outcomes for newborns with pink eye are good, according to StatPearls.

Research and Statistics: Who Gets Pink Eye?

Anyone can get pink eye. In previous research, estimates have put the number of acute conjunctivitis cases in this country as high as six million annually.

Viral conjunctivitis accounts for up to 80 percent of all acute infectious cases of pink eye. Bacterial conjunctivitis, however, is the most common cause in children.

Allergic conjunctivitis affects up to 40 percent of the population, most frequently occurring in spring and summer months.

According to one study, the cost of treating bacterial conjunctivitis alone has been estimated at between $377 million and $857 million per year.

Related Conditions and Causes of Pink Eye

Conjunctivitis has been associated with certain conditions, including psoriatic disease, the removal of enlarged adenoids, and sexually transmitted diseases (STDs).

Psoriatic Disease

Psoriasis and psoriatic arthritis are autoimmune disorders in which the body’s immune system attacks healthy cells and tissues. Though they are most commonly associated with skin and joint pain, these conditions can affect other parts of the body.

When a psoriasis flare-up occurs around the eyes, the eyelids and eyelashes become red and crusty and covered in scales. Further irritation can occur when the rims of the eyelids turn down and the lashes rub against the eyeballs.

According to a report published in January 2020 the journal Journal of Family Medicine and Primary Care, conjunctivitis prevalence rates in psoriasis patients may exceed 64 percent.

Learn More About Eye Problems and Psoriatic Arthritis

Adenoid Removal (Adenoidectomy)

Research suggests that tonsil (tonsillectomy) and adenoid removal (known as adenoidectomy) are associated with certain allergic and infectious diseases.

Adenoid glands at the back of the nasal passage help prevent bacteria and viruses from entering the body through the nose. If they become too large, they can cause sinus or breathing problems and may require removal.

According to a study published in July 2018 in JAMA Otolaryngology, removal of the adenoids has been linked with a nearly doubled relative risk of conjunctivitis.

Learn More About an Adenoidectomy

Sexually Transmitted Infections

Gonococcal conjunctivitis is a type of conjunctivitis that is caused by Neisseria gonorrhoeae, the bacteria that causes the sexually transmitted disease gonorrhea. Though considered rare in adults, the disease can spread to the eye through contact, according to StatPearls.

Chlamydia trachomatis infection, or chlamydia, can cause certain types of conjunctivitis such as inclusion conjunctivitis and trachoma, notes the CDC.

Gonococcal and chlamydial conjunctivitis can also occur in newborns because a mother can pass on infectious conjunctivitis during childbirth.

Learn More About Sexually Transmitted Diseases (STDs)

Resources We Love

Favorite Organizations for Essential Pink Eye Info

American Academy of Ophthalmology (AAO)

Learn the fundamentals of pink eye from the professional medical association of ophthalmologists (medical doctors who specialize in eye care). The site displays some visual examples of conjunctivitis, as well as quick home remedies.

American Optometric Association (AOA)

The AOA looks at the essential aspects of pink eye, including causes, diagnosis, and treatment. Because good hygiene is one of the best ways to control conjunctivitis, the association instructs readers on best practices to prevent this inflammation.

The College of Optometrists

The College of Optometrists highlights guidelines on the diagnosis and management on a type of conjunctivitis that occurs in newborns within the first month of life. The cause is a sexually transmitted disease in a parent. The site discusses diagnosis, prevention, and treatment.

Centers for Disease Control and Prevention (CDC)

The CDC gives in-depth information about causes, treatments, and the different types of pink eye, including viral, bacterial, and allergic conjunctivitis. The site features a podcast by a pediatrician who specializes in the condition.

HealthyChildren.org

A digital extension from the American Academy of Pediatrics, this group answers parents’ health questions regarding kids of all ages, including inquiries concerning conjunctivitis. For example: “Do I need to keep my son home if he has pink eye?”

National Eye Institute (NEI)

Part of the National Institutes of Health, the NEI lays out the facts about pink eye, telling you how to recognize it, take care of it, and avoid getting it altogether. You can also search for news, events, and latest research on the topic.

Favorite Organizations for Related Pink Eye Info

American Board of Internal Medicine Foundation (ABIMF)

ABIMF supports the Choosing Wisely initiative to promote conversations between clinicians and patients. The site addresses several eye-heath subjects, such as conjunctivitis. The website explains when antibiotics are and aren’t needed for pink eye.

Measles and Rubella Initiative

Because measles has been making a comeback recently among unvaccinated children and pink eye can be a symptom of measles, it’s helpful to know other symptoms of measles and how to identify the potentially life-threatening disease. The Measles and Rubella Initiative describes the serious health consequences from measles and why vaccination is so important.

Additional reporting by Shira Feder.

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