What Is Pink Eye, or Conjunctivitis?

Pink eye, also known as conjunctivitis, can affect everyone globally—from children to adults. The condition gets its name from causing a bloodshot red hue in the eye, and it can affect one or both eyes. Additionally, pink eye tends to be a common reason for medical and ophthalmological office visits.

Below is more about pink eye, including information such as symptoms, causes, treatment, and more.

What Causes Pink Eye—And How Contagious Is It?

There are a few causes of pink eye. The most common causes of conjunctivitis are:

• Infections (viral or bacterial)
• Allergens
• Other irritants (e.g., smoke, chemicals, dust)

Also, pink eye can result from changes in bacteria that live on the conjunctiva (the clear film covering the inner eyelid and the white part of the eye).

But although all cases of pink eye are not contagious, you should treat any cases as being contagious until you determine the type of infection you have.

Viral and Bacterial Conjunctivitis

Viruses are the leading cause of infectious pink eye. Viral pink eye may be diagnosed based on medical history and symptoms. Pink eye that appears with a cold or upper respiratory infection increases the likelihood that a person's pink eye symptoms are due to a virus.

Bacterial pink eye is more common in children due to close contact with others in school and daycare. Newborns are also at risk of getting pink eye from mothers with sexually transmitted infections (STIs) such as chlamydia and gonorrhea.

Pink eye can spread in different ways. People can end up with viral or bacterial pink eye by way of:

• Hand contact with contaminated objects or hands (e.g., shaking hands), then touching your eyes before handwashing
• Eye contact with contaminated objects
• Air (e.g., through respiratory droplets from breathing, talking, coughing, or sneezing)
• Sexual activity with eye-to-genital contact or from a mother to a baby, in the case of bacterial pink eye

Of note, viral pink eye is highly contagious and most commonly spreads through hand-to-eye contact. Your hands can get contaminated by touching tears or discharge from infected eyes, fecal matter, and respiratory droplets on surfaces.

Allergen or Irritant Conjunctivitis

Allergic pink eye occurs when the body mounts a response to an allergen, such as pollen, mold, animal dander, or dust. Some cases of allergic pink eye are due to other environmental irritants, such as:

• Chemicals
• Air pollution due to vapors, fumes, or smoke
• Other irritants (e.g., cosmetics or contact lenses)

Allergic pink eye can also be seasonal. It may occur along with other allergy symptoms, like sneezing and an itchy nose, and often affects people in families with a history of hay fever (also known as allergic rhinitis), asthma, or eczema.

There's no risk of transmission if the cause of conjunctivitis is an allergen or irritant. Allergic pink eye occurs when the body unleashes a response to pollen, dust mites, animal dander, or another allergen. Irritants, such as cosmetics or chlorine in pool water, can cause pink eye, but in this case, the condition cannot be passed along to someone else.

Pink Eye Signs and Symptoms

The inflamed conjunctiva makes blood vessels appear more prominent than usual. The eye appears pink or red, and the inner eyelid can get puffy and pink, too. Symptoms of pink eye can include:

• Redness
• Itching
• Excess tearing
• Eye pain
• Blurred vision
• Sensitivity to light

Eye discharge may vary depending on the type of pink eye. After a night of sleep, their eyelids may crust over and even be dried shut. People with pink eye may also find that their eyelashes get stuck together.

What the Condition May Look Like: Pictures of Pink Eye

The conjunctiva swells up, making blood vessels appear larger than usual. Eyelids become pink and puffy.

When allergens—or other irritants—are the culprit, pink eye is very itchy and produces a watery discharge.

In newborns, pink eye causes red, puffy eyelids. Children may also have discharge, swelling of the conjunctiva, and swollen eyelids.

How Does Pink Eye Affect Children?

Bacteria and viruses that cause pink eye are easily transmitted from hand to eye, which is why toddlers and school-aged children are especially at risk. A child can get pink eye while in preschool or when playing on playgrounds.

With neonatal conjunctivitis (sometimes also known as ophthalmia neonatorum), newborn babies' eyes may be infected during vaginal delivery. This infection can happen if, as noted, the mother has an untreated sexually transmitted infection (STI) (such as chlamydia or gonorrhea) as well as from other non-sexually transmitted bacteria and viruses.

How Is Pink Eye Diagnosed?

Healthcare providers diagnose pink eye based on a patient's medical history, eye exam, and other physical signs and symptoms.

Redness and swelling are common pink eye symptoms, but other symptoms of pink eye may depend on the underlying cause. Often, the consistency and color of eye discharge provide important diagnostic clues.

A healthcare provider may collect a sample of eye secretions for laboratory testing to determine the type of pink eye infection you have in order to find out the best treatment.

How To Prevent Pink Eye

Good hygiene can go a long way toward preventing the transmission of pink eye. To protect yourself from reinfection, and others from acquiring pink eye, follow these tips from the CDC:

• Wash your hands frequently with soap and water.
• Try not to touch or rub your eyes, especially if you have pink eye in one eye—you might infect the other eye.
• Use a clean cloth or fresh cotton ball to clear mucus and pus from your eye. Throw away used cotton balls immediately after use, and launder washcloths in hot water and detergent.
• Wash your hands after applying eye drops or ointment for pink eye and after close contact with someone with pink eye.
• Do not share personal items that may have touched your eyes (e.g., towels, bedding, cosmetics), sheets, pillowcases, and cosmetics.
• Wash the bath and bed items used by a person with pink eye in hot water and detergent.

Additionally, avoid reinfection by throwing out or cleaning items such as eyeglass cases, eye and face makeup, and contact lenses.

Treatments for Pink Eye

Pink eye remedies vary depending on the cause and the individual affected. Many cases improve on their own without medication within days.

In some cases of bacterial conjunctivitis, topical antibiotics may be used. And in some serious cases of viral conjunctivitis, antivirals may be part of treatment.

Home remedies may also be helpful. For example, you can apply a warm, moist compress to the eye several times a day to relieve swelling and irritation due to viral or bacterial infection.

Specific Treatments by Type of Pink Eye

Viral pink eye usually clears in a week or two without treatment. The CDC says it can take longer—around two to three weeks—if complications occur. Antiviral medicines may be prescribed for more serious cases (such as pink eye caused by the herpes simplex virus or the varicella-zoster virus).

Mild cases of bacterial conjunctivitis often improve in days without treatment but can last up to two weeks. Antibiotic eyedrops or ointments can speed recovery, reduce complications, and lower the risk of transmission. Antibiotic treatment is generally recommended for:

• Serious symptoms
• People with weak immune systems
• People whose symptoms do not improve

Allergic pink eye usually clears up after exposure to the allergen is reduced or eliminated or when treatment is given. Allergy medicines and certain eye drops may provide symptom relief. Pink eye caused by irritants typically improves after the irritant is removed.

People who get pink eye from wearing contact lenses may need to switch to a new pair of lenses, a new disinfection solution, or even take a break from wearing contacts.

Pink Eye Treatment for Children

Depending on the type of conjunctivitis a newborn develops, they may need oral or intravenous antibiotics, eye drops, or ointments to ward off potentially serious complications.

Compresses may ease swelling and irritation. Allergy medicines may help kids with allergic pink eye. Antibiotic drops are only prescribed for bacterial forms of pink eye.

Sometimes babies develop pink eye after receiving routine eye drops given after birth to prevent eye infection. The irritation usually clears up within a few days. Newborns can also develop red, irritated eyes due to a clogged tear duct. Parents can treat it at home by using a clean hand to gently massage the area between the baby's eye and nose.

See a healthcare provider to help determine the cause of your child's symptoms and appropriate treatment.

When To See a Healthcare Provider for Pink Eye

For some cases of pink eye, it may be important to see a healthcare provider. A primary care physician (PCP) can treat most pink eye cases.

However, you may be referred to an ophthalmologist or allergist for evaluation based on symptoms, severity, and response to treatment. A pediatrician should evaluate children to determine the cause of symptoms and appropriate treatment.

Per the CDC, seek medical attention for:

• Intense eye redness
• Eye pain
• Symptoms that do not improve with treatment
• Sensitivity to light
• Blurred vision that persists after cleaning eye secretions
  

Other situations that may warrant immediate medical attention are:

• Symptoms that last more than three to four days or an extended period of time
• Swelling of the eyelids or area surrounding the eye
• The presence of a headache or other co-occurring symptoms

Certain individuals with bacterial conjunctivitis will need to see an ophthalmologist (a medical eye healthcare professional). Those include people with contact lens wearers with bacterial conjunctivitis, hyperacute bacterial conjunctivitis, and chronic bacterial conjunctivitis.

Newborns with pink eye require immediate medical care. Babies exposed to bacteria during vaginal birth need antibiotics to clear the infection. Without treatment, conjunctivitis caused by gonorrhea can lead to vision complications.

Further, anyone with a weakened immune system due to HIV, cancer treatment, or other medical conditions or treatments should seek treatment for pink eye.

A Quick Review

Pink eye, or conjunctivitis, is an eye infection that can be contagious, depending on the type of pink eye a person has. Some of the ways it can be spread include hand-to-eye contact, through the air, or close contact (e.g., shaking hands).

Pink eye can be prevented with methods such as washing your hands and not sharing contaminated items. But the condition is still treatable, and treatment will vary depending the kind of pink eye you've been diagnosed with.