Pink eye, or conjunctivitis, is a frequent and unwelcome eye infection. The symptoms, which include swollen and red eyes, crusty discharge, and a sticky feel, often lead those affected to want to hide from public view.

Annually, around six million people in the U.S. deal with this condition, and they typically wish to avoid other unpleasant symptoms like extreme sensitivity to light, a burning sensation, and itchiness so intense it can cause some to unintentionally pull out eyelashes.

Aside from personal discomfort or feelings of shame, most individuals are concerned about unintentionally transmitting the infection to family, friends, or even strangers. Gaining a better understanding of how various types of pink eye spread is essential to prevent this.

What exactly is pink eye?

Pink eye, also referred to as conjunctivitis, occurs when the conjunctiva—the thin outer layer of the eye—becomes infected and inflamed. “It’s the most commonly diagnosed eye condition in emergency care settings across the United States,” explains Dr. Daniel Shapiro, a pediatric emergency physician at UCSF Benioff Children’s Hospital in San Francisco. “Most individuals will experience conjunctivitis at some point in their lives, especially during early childhood and early adulthood.”

There are several causes of pink eye, including viral infections, bacterial infections, chemical irritants, or allergies. “Viral conjunctivitis tends to be more prevalent in fall and winter,” notes Dr. John Epling, a family physician and professor of population health at the Virginia Tech Carilion School of Medicine. This is often due to an uptick in respiratory illnesses caused by similar viruses, as seen with the rapid spread of the COVID variant Arcturus in fall 2023. On the flip side, “allergic conjunctivitis can occur in spring, summer, or fall, depending on a person’s specific allergies,” he adds.

Can pink eye be contagious?

The timing of symptoms is significant because the type of pink eye dictates whether a person is contagious and the typical duration of symptoms. “Viral conjunctivitis usually lasts from a few days to a week,” explains Epling. In contrast, bacterial pink eye continues until treated with drops or ointments, “but should clear up shortly after treatment.” Allergic conjunctivitis “will persist as long as allergens like pollen are present but can be managed with medications and by avoiding those allergens.” For toxic or chemical conjunctivitis, “it’s crucial to get medical attention quickly since treatment depends on what caused the exposure,” advises Epling.

Among the various forms of pink eye, only infectious conjunctivitis (caused by viruses or bacteria) is contagious, states Shapiro. This type can spread through direct contact with infected individuals or via contaminated surfaces. “Some viral conjunctivitis can coincide with a broader viral illness, where an infected person may also show symptoms like fever, cough, or fatigue,” he explains. In these situations, “the virus can spread through contact or droplets, potentially causing conjunctivitis alongside other viral symptoms.”

Epling cautions that both virus- and bacteria-related conjunctivitis “is highly contagious” and can quickly spread in settings like schools and daycare centers.

Ways to prevent pink eye

Given its contagious nature, Shapiro emphasizes that the best preventive measure against bacterial or viral pink eye is to avoid close contact with anyone exhibiting symptoms and refrain from sharing items like eyeglasses, makeup, eye drops, towels, or bedding.

For pink eye resulting from seasonal allergies, steering clear of allergens (when possible) or utilizing appropriate antihistamine or anti-inflammatory eye drops can be beneficial, according to Epling.

If you have infectious pink eye and want to minimize the risk of spreading it, it’s advisable to limit close contact with others while symptoms are present, avoid touching your eyes, maintain proper hygiene by frequently washing hands, and refrain from sharing personal items or swimming in public pools, in line with recommendations from the U.S. Centers for Disease Control and Prevention.

To ease symptoms, Epling suggests using a warm compress, obtaining antibiotic drops or ointment for bacterial conjunctivitis (“antibiotics typically are ineffective for viral conjunctivitis,” he notes), rinsing the eyes gently with cool or lukewarm water, or applying artificial tears to alleviate dryness and soothe inflammation.

“If symptoms persist for more than a few days, it’s best to consult a doctor as there may be complications,” Epling advises. “Most primary care professionals can treat conjunctivitis, though sometimes, an eye specialist may be necessary.”