Conjunctivitis in Adults and Children: Causes, Contagion, and Care

Conjunctivitis, often called pink eye, is a common condition that causes redness and irritation of the clear membrane covering the white part of the eye and inner eyelids. In adults and children, the cause may be viral, bacterial, allergic, or irritant-related, and treatment depends on the underlying reason.

Overview

Conjunctivitis is inflammation of the conjunctiva, the thin, clear tissue that lines the inside of the eyelids and covers the white part of the eye. When this tissue becomes irritated or infected, the eye may look red or pink, feel gritty, and produce watery or sticky discharge. Because the condition is so common, many people refer to it simply as pink eye.

Conjunctivitis can affect both adults and children. It may involve one eye at first and then spread to the other, especially when the cause is infectious. While it is often mild and self-limited, symptoms can be uncomfortable and may interfere with work, school, reading, or screen use.

There are several main types of conjunctivitis. Viral conjunctivitis is commonly linked to colds and other upper respiratory infections. Bacterial conjunctivitis is caused by bacteria and may lead to thicker discharge. Allergic conjunctivitis happens when the eyes react to allergens such as pollen or pet dander. Irritant conjunctivitis can occur after exposure to smoke, chlorine, cosmetics, or other substances.

Most cases improve with simple care and time, but it is important to identify the cause correctly. A red eye is not always conjunctivitis, and other eye problems can look similar. If symptoms are severe or unusual, an ophthalmologist can help rule out more serious conditions.

Symptoms

The symptoms of conjunctivitis can vary depending on the cause, but redness of the white part of the eye is one of the most typical signs. Many people also notice tearing, burning, itching, mild swelling of the eyelids, or a feeling that something is in the eye. The eyes may be more uncomfortable in bright light, although true severe light sensitivity is less typical and should be assessed by a doctor.

Viral conjunctivitis often causes watery discharge and may begin in one eye before affecting the other. It may occur along with a sore throat, runny nose, cough, or swollen lymph nodes near the ear. Bacterial conjunctivitis is more likely to cause thicker yellow, white, or green discharge that can make the eyelids stick together, especially after sleep.

Allergic conjunctivitis commonly affects both eyes at the same time and causes intense itching, watering, and puffiness. It may happen seasonally or continue throughout the year, depending on the trigger. Sneezing and nasal allergy symptoms are also common.

Young children may not always describe symptoms clearly. Instead, parents may notice frequent eye rubbing, crusting on the lashes, watery eyes, or reluctance to open the eyes in bright light. Although many cases are minor, persistent redness or discharge in a child should still be discussed with a healthcare professional.

• Red or pink appearance of the eye
• Watery or sticky discharge
• Itching, burning, or grittiness
• Eyelid swelling or crusting
• Mild blurred vision that clears with blinking or wiping discharge

Causes and Risk Factors

Viral conjunctivitis is one of the most common forms and is often caused by adenoviruses, the same group of viruses that can cause colds and sore throats. It spreads easily in homes, schools, offices, and daycare settings. Bacterial conjunctivitis can be caused by several different bacteria and is more common when there is close contact, poor hand hygiene, or contamination from shared items.

Allergic conjunctivitis is not an infection. Instead, it happens when the immune system reacts to allergens such as pollen, dust mites, mold, or animal dander. Irritant conjunctivitis may develop after exposure to smoke, air pollution, chlorinated water, shampoo, make-up, or contact lens solutions. Contact lenses themselves can also irritate the eye or raise the risk of infection if they are worn too long or cleaned improperly.

Certain factors make conjunctivitis more likely. These include having close contact with someone who has an eye infection, touching the eyes with unwashed hands, having seasonal allergies, and wearing contact lenses. Children may be at higher risk because infections spread easily in group settings and because hand-to-eye contact is frequent.

Although most conjunctivitis is straightforward, red eyes can also occur with more serious eye problems such as keratitis, uveitis, glaucoma, or eye injury. That is one reason persistent or severe symptoms should not be assumed to be simple pink eye. Conditions such as glaucoma can also cause a painful red eye, but they require very different treatment.

Is Conjunctivitis Contagious?

Whether conjunctivitis is contagious depends on the cause. Viral and bacterial conjunctivitis can spread from person to person, while allergic and irritant conjunctivitis do not. Viral conjunctivitis is often especially contagious, particularly in the first several days when tearing and discharge are present.

Infectious conjunctivitis spreads mainly through hand contact with eye secretions or contaminated surfaces. It can also spread through shared towels, pillowcases, cosmetics, eye drops, and contact lens cases. Children may pass it on through close play, shared toys, and classroom contact.

To reduce spread, people with infectious conjunctivitis should wash their hands often, avoid rubbing their eyes, and use a clean tissue or cotton pad each time they wipe discharge. Personal items such as towels, washcloths, make-up, and pillowcases should not be shared. Contact lenses should be removed and not worn again until a clinician says it is safe.

Return to school or work depends on the cause, symptom severity, and local guidance. Some people improve quickly, while others remain contagious for longer. When there is uncertainty, especially for children in school or daycare, a healthcare professional can advise on when it is reasonable to return.

Diagnosis

Diagnosis usually begins with a medical history and an eye examination. A doctor asks about the timing of symptoms, whether one or both eyes are involved, the type of discharge, recent colds, contact with someone who has pink eye, allergy history, and contact lens use. These details often help distinguish viral, bacterial, allergic, and irritant causes.

During the exam, the doctor looks at the surface of the eye, the conjunctiva, the eyelids, and the pattern of redness. They may also check vision and ask about pain or light sensitivity. In many uncomplicated cases, no special testing is needed.

Sometimes conjunctivitis resembles another condition, and further assessment may be necessary. This is especially true if there is significant pain, reduced vision, severe swelling, corneal involvement, or symptoms that do not improve as expected. Contact lens users may need a more careful evaluation because they have a higher risk of corneal infection.

In selected situations, a sample of discharge may be tested, particularly when infection is severe, recurrent, unusual, or seen in newborns. If the diagnosis is uncertain or another eye disease is suspected, a person may be referred for a detailed eye examination by an eye specialist.

Treatment Options

Treatment depends on the underlying cause. Viral conjunctivitis usually improves on its own with supportive care such as artificial tears, cool compresses, and gentle cleaning of discharge from the eyelids. Antibiotics do not treat viral infections, so they are not helpful in most viral cases.

Bacterial conjunctivitis may also improve without complication, but some cases are treated with antibiotic eye drops or ointment to shorten symptoms or reduce spread. A doctor will decide whether this is appropriate based on age, severity, discharge, and other factors. It is important to use medicines only as prescribed and to avoid using someone else’s eye drops.

Allergic conjunctivitis is usually managed by avoiding triggers where possible and using treatments that reduce the allergic reaction, such as lubricating drops or anti-allergy eye drops recommended by a clinician. People who have ongoing allergic eye symptoms may also benefit from an assessment for related allergy conditions. If a different eye problem is suspected, doctors may recommend further care such as corneal treatment when the cornea is involved, though this is not typical for simple conjunctivitis.

Contact lenses should be stopped until the eye is fully better and medical advice has been followed. Any lenses, storage cases, or eye make-up used during the infection may need to be replaced to avoid reinfection. In more complex cases, an ophthalmologist may assess for other problems and recommend specialized eye testing if symptoms do not fit routine conjunctivitis.

Prevention and Self-care

Good hygiene is the most important step in preventing infectious conjunctivitis. Hands should be washed frequently with soap and water, especially after touching the eyes, face, or respiratory secretions. Alcohol-based hand gel may help when soap and water are not available, but visible eye discharge should be cleaned away gently first.

At home, it helps to use separate towels and washcloths, change pillowcases regularly, and avoid sharing cosmetics or eye products. People should avoid rubbing their eyes because this can worsen irritation and spread infection to the other eye or to other people. Make-up used during an episode of conjunctivitis is best discarded.

For comfort, cool compresses can soothe viral or allergic conjunctivitis, while lubricating eye drops may reduce dryness and grittiness. Contact lenses should not be worn while the eyes are red or discharging. For people with allergies, reducing exposure to pollen, dust, and pet dander may lower the chance of flare-ups.

If symptoms are frequent, recurrent, or linked to another eye condition, a full ophthalmic review can be helpful. Acıbadem Health Point’s multidisciplinary specialists in JCI-accredited hospitals diagnose and treat eye conditions for international patients, including causes of persistent red eye that may need specialist eye care beyond routine home management.

When to See a Doctor

Most cases of conjunctivitis are mild, but some symptoms should prompt medical attention. A doctor should assess severe eye pain, sensitivity to light, reduced or blurred vision that does not clear with blinking, marked swelling, or redness that is getting worse rather than better. These features may point to a problem other than simple conjunctivitis.

Contact lens wearers should seek advice promptly if they develop a red eye, discharge, or pain, because contact lens-related infections can affect the cornea and need timely treatment. Babies with eye redness or discharge should also be evaluated quickly, as newborn eye infections require special care.

Medical review is also sensible if symptoms last longer than expected, keep coming back, or do not improve with simple measures. People with weakened immune systems or recent eye surgery should be especially cautious. A clinician can make sure the diagnosis is correct and that treatment is safe.

In general, conjunctivitis is manageable and often settles well with the right care. The key is to recognize the likely cause, prevent spread when it is infectious, and seek help when warning signs appear. Eye specialists can also evaluate similar problems such as other eye conditions if redness or visual changes seem unusual.

Frequently asked questions