Conjunctivitis (Pink Eye): Symptoms, Causes & Treatment

What Is Conjunctivitis (Pink Eye)?

Conjunctivitis is an inflammation of the conjunctiva, the thin, clear tissue that lines the white part of the eye and the inside of the eyelids. It causes redness, itching, discharge, and a gritty feeling in the eyes. Also called pink eye, it is one of the most common and treatable eye conditions in both children and adults.

The conjunctiva is a thin, transparent membrane that serves as a protective barrier for your eye. It covers the sclera (the white part of your eye) and lines the inner surface of your eyelids. When this membrane becomes inflamed due to infection, allergies, or irritants, the tiny blood vessels within it become more prominent, giving the eye its characteristic pink or reddish appearance.

Conjunctivitis affects approximately 6 million people in the United States each year, making it one of the leading causes of doctor visits for eye complaints. The condition is particularly common in children and spreads easily in daycare centers, schools, and other environments where people are in close contact. However, people of all ages can develop conjunctivitis, and most cases resolve without complications when properly managed.

The condition can affect one or both eyes and typically begins in one eye before spreading to the other within a day or two. While conjunctivitis can be uncomfortable and concerning due to its visible symptoms, it rarely causes long-term damage to vision when treated appropriately. Understanding the different types of conjunctivitis and their causes is essential for proper management and prevention of spread to others.

Types of Conjunctivitis

Understanding the type of conjunctivitis you have is crucial because it determines the appropriate treatment approach. Each type has distinct characteristics, causes, and treatment requirements. Healthcare providers typically classify conjunctivitis into three main categories based on the underlying cause.

Viral conjunctivitis is the most common form and is typically caused by adenoviruses, the same viruses responsible for the common cold. This type often accompanies upper respiratory infections and produces a watery discharge. Viral conjunctivitis is highly contagious and typically affects both eyes, though symptoms may start in one eye and spread to the other. It generally resolves on its own within 7-14 days without specific treatment.

Bacterial conjunctivitis is caused by various bacteria, including Staphylococcus aureus, Streptococcus pneumoniae, and Haemophilus influenzae. This type typically produces a thicker, yellow-green discharge that may cause the eyelids to stick together, especially upon waking. Bacterial conjunctivitis can affect one or both eyes and may require antibiotic eye drops or ointment for faster resolution, though mild cases often improve without treatment.

Allergic conjunctivitis occurs when your eyes react to allergens such as pollen, dust mites, pet dander, or mold. Unlike infectious forms, allergic conjunctivitis is not contagious. It typically affects both eyes simultaneously and causes intense itching, redness, and watery discharge. Symptoms often occur seasonally (hay fever) or year-round depending on the allergen exposure.

What Are the Symptoms of Conjunctivitis?

Common symptoms of conjunctivitis include pink or red color in the white of the eye, increased tearing, thick discharge that crusts over eyelashes (especially in bacterial cases), itching and burning sensation, gritty feeling as if something is in the eye, and mild sensitivity to light. Symptoms vary depending on whether the cause is viral, bacterial, or allergic.

The symptoms of conjunctivitis can range from mild discomfort to more noticeable changes in the appearance and function of your eyes. Most people first notice redness in the white part of one or both eyes, which occurs because the tiny blood vessels in the conjunctiva become inflamed and more visible. This redness gives the condition its common name, "pink eye."

Alongside the characteristic redness, you may experience increased tearing or discharge from the affected eye. The nature of this discharge provides important clues about the underlying cause: viral conjunctivitis typically produces a watery, clear discharge, while bacterial conjunctivitis often causes a thicker, yellow-green pus-like discharge that can cause the eyelids to stick together after sleep.

Many people with conjunctivitis describe a gritty or sandy sensation, as if there is something in their eye. This uncomfortable feeling is caused by the inflammation of the conjunctiva and can make blinking uncomfortable. You may also experience itching, which is particularly prominent in allergic conjunctivitis but can occur with all types. Some degree of light sensitivity (photophobia) is common, though severe sensitivity may indicate a more serious condition requiring medical attention.

Swelling of the eyelids and the conjunctiva itself can occur, making the eyes appear puffy. In some cases, you may notice small bumps (follicles) on the inside of your eyelids if you gently pull down the lower lid and look in a mirror. These symptoms typically develop gradually over a day or two after exposure to the causative agent.

Symptoms in Newborns and Infants

Newborn babies may have slightly sticky eyes without having conjunctivitis, which occurs because their tear ducts are narrower than those of older children and adults. This normal stickiness appears as a clear or slightly white discharge and does not cause redness or swelling. However, if a newborn develops red, swollen eyes or significant discharge with pus, this may indicate a serious infection acquired during birth, such as from chlamydia or gonorrhea, and requires immediate medical attention.

Conjunctivitis in newborns (ophthalmia neonatorum) is a medical emergency because the bacteria can quickly damage the delicate eye tissues. Any newborn under one month of age with symptoms of conjunctivitis should be evaluated by a healthcare provider immediately. The infection may have been transmitted during passage through the birth canal and can cause serious complications if not treated promptly.

What Causes Conjunctivitis?

Conjunctivitis is caused by viral infections (most common, often with colds), bacterial infections (producing thick discharge), allergic reactions to pollen, dust, or pet dander, or irritants like smoke, chlorine, or foreign bodies in the eye. Understanding the cause helps determine appropriate treatment.

The causes of conjunctivitis can be broadly categorized into infectious and non-infectious origins. Each cause produces slightly different symptoms and requires different approaches to treatment. Identifying the underlying cause is essential for effective management and for preventing unnecessary spread of contagious forms.

Viral infections account for the majority of conjunctivitis cases, with adenoviruses being the most common culprit. These are the same viruses that cause the common cold, and conjunctivitis often develops alongside cold symptoms like runny nose, sore throat, and cough. Other viruses that can cause conjunctivitis include herpes simplex virus, varicella-zoster virus (which causes chickenpox and shingles), and enterovirus. Viral conjunctivitis typically spreads through respiratory droplets and direct contact with infected secretions.

Bacterial infections can be caused by various bacteria, with Staphylococcus aureus, Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis being common culprits in children. In adults, Staphylococcus species are more frequently responsible. Bacterial conjunctivitis spreads through direct contact with contaminated hands, towels, or other objects. In rare cases, sexually transmitted bacteria like Chlamydia trachomatis and Neisseria gonorrhoeae can cause conjunctivitis, particularly in newborns exposed during birth.

Allergic reactions trigger conjunctivitis when the immune system overreacts to normally harmless substances. Seasonal allergens like pollen cause hay fever conjunctivitis that occurs at specific times of year. Perennial allergens such as dust mites, mold, and pet dander can cause year-round symptoms. Contact allergens, including certain cosmetics, eye drops, or contact lens solutions, may also trigger allergic conjunctivitis in sensitive individuals.

Irritants can cause conjunctivitis through direct physical or chemical irritation of the eye. These include smoke, pollution, chlorine in swimming pools, foreign particles in the eye, and chemical splashes. Unlike infectious or allergic forms, irritant conjunctivitis typically resolves quickly once the irritating substance is removed and is not contagious.

Risk Factors for Developing Conjunctivitis

Several factors can increase your likelihood of developing conjunctivitis. Close contact with someone who has the infection significantly raises your risk, which is why outbreaks commonly occur in schools, daycare centers, and households. Contact lens wearers face higher risk, especially if they don't follow proper hygiene practices like hand washing before handling lenses, regular lens replacement, and proper storage solution use.

People with allergies are prone to allergic conjunctivitis, and their symptoms may worsen during high pollen seasons or when exposed to known triggers. Individuals with weakened immune systems, whether from illness, medications, or other causes, may be more susceptible to infectious conjunctivitis and may experience more severe symptoms. Working in dusty or smoky environments, spending time in crowded places, or having a recent upper respiratory infection also increases your risk.

When Should You See a Doctor for Pink Eye?

See a doctor immediately if you experience severe eye pain, significant vision changes, intense light sensitivity, symptoms that don't improve within 5 days, heavy yellow or green discharge, or if a newborn under 1 month has eye symptoms. Contact lens wearers and people with weakened immune systems should also seek prompt medical attention.

While most cases of conjunctivitis are mild and resolve on their own with home care, certain symptoms warrant medical attention. Understanding when to seek professional help can prevent complications and ensure appropriate treatment. If you're uncertain whether your symptoms require medical evaluation, it's always better to err on the side of caution and consult a healthcare provider.

You should contact a healthcare provider or visit an eye clinic if you experience any of the following warning signs that may indicate a more serious condition:

• Severe eye pain that is not relieved by over-the-counter pain medications
• Vision changes including blurred vision that doesn't clear with blinking
• Intense sensitivity to light (photophobia) that makes it difficult to open your eyes
• Heavy discharge that is yellow or green in color, particularly if copious
• Symptoms that persist for more than 5 days or worsen despite home treatment
• Redness in only one eye accompanied by significant pain
• Blisters or rash near the eye or on the eyelids

Contact lens wearers should take conjunctivitis symptoms particularly seriously because bacteria can multiply rapidly on contact lenses and cause corneal infections (keratitis), which can lead to permanent vision damage. Remove your contact lenses immediately if you develop symptoms and do not wear them until your symptoms have completely resolved and your healthcare provider has given approval.

How Can You Treat Conjunctivitis at Home?

Home treatment for conjunctivitis includes cleaning your eyes several times daily with warm water and a clean cloth, wiping from the outer corner toward the nose, using a fresh cloth for each wipe, applying cool compresses for allergic conjunctivitis or warm compresses for infectious types, and using artificial tears for comfort. Good hand hygiene is essential to prevent spreading.

Many cases of conjunctivitis can be effectively managed at home with proper care and hygiene. The goal of home treatment is to relieve symptoms, prevent the spread of infection, and support the body's natural healing process. Whether your conjunctivitis is viral, bacterial, or allergic, these self-care measures can help you feel more comfortable while the condition resolves.

The most important aspect of home treatment is maintaining good eye hygiene through regular cleaning. When discharge builds up on your eyelids and eyelashes, it can be uncomfortable and may worsen symptoms. Proper cleaning technique is essential to avoid spreading infection from one eye to the other or reintroducing bacteria to the affected eye.

Step-by-Step Eye Cleaning Instructions

To properly clean your eyes during a conjunctivitis infection, follow these steps carefully. This process should be repeated several times throughout the day, especially when discharge accumulates.

1. Wash your hands thoroughly with soap and water for at least 20 seconds before touching your eyes or preparing to clean them
2. Moisten a clean cotton ball or soft tissue with lukewarm water - avoid using tap water directly in your eye
3. Gently wipe from the outer corner toward the inner corner (toward your nose) - this direction helps prevent pushing discharge into the tear ducts
4. Use a new cotton ball or tissue for each wipe - never reuse cleaning materials as this can spread bacteria
5. If both eyes are affected, clean each eye separately using different cotton balls to prevent cross-contamination
6. If eyes are stuck together, soak a compress in warm water and hold it against your closed eyelids for 1-2 minutes to soften the crust before wiping
7. Wash your hands again after cleaning your eyes to prevent spreading infection

Comfort Measures for Conjunctivitis

Beyond cleaning, several measures can help relieve the discomfort associated with conjunctivitis. Applying compresses to your closed eyelids can provide significant relief. For allergic conjunctivitis, cool compresses help reduce itching and swelling by constricting blood vessels. For viral or bacterial conjunctivitis, warm compresses can help loosen crusted discharge and soothe irritation.

Artificial tears (lubricating eye drops) can help wash away irritants and provide relief from the gritty, dry sensation that often accompanies conjunctivitis. These are available without prescription and can be used multiple times throughout the day. Look for preservative-free formulations if you need to use them frequently. However, avoid using eye drops that "get the red out" as these can cause rebound redness and irritation.

If you normally wear contact lenses, switch to glasses until your symptoms have completely resolved. Contact lenses can trap bacteria against the eye and slow healing. You should also discard any contact lenses that were in your eyes when symptoms began, as well as their storage case and solution, to prevent reinfection.

How Can You Prevent Spreading Conjunctivitis?

Prevent spreading conjunctivitis by washing hands frequently and thoroughly, avoiding touching or rubbing your eyes, not sharing personal items like towels and makeup, changing pillowcases daily, staying home from work or school when symptoms are severe, and disinfecting frequently touched surfaces.

Conjunctivitis caused by viruses and bacteria spreads easily from person to person through direct and indirect contact. The infection can be transmitted when you touch your eyes and then touch objects that others will handle, or through respiratory droplets when coughing or sneezing. Understanding how the infection spreads is key to preventing transmission to family members, coworkers, and the broader community.

Proper hand hygiene is the single most effective way to prevent spreading conjunctivitis. The viruses and bacteria that cause pink eye can survive on surfaces and hands for extended periods, making frequent hand washing essential. Wash your hands thoroughly with soap and water for at least 20 seconds, especially after touching your eyes, face, or items that have come in contact with your eyes.

Preventing Spread in Your Household

When someone in your household has conjunctivitis, taking extra precautions can help protect other family members from infection. These measures are particularly important when living with young children, elderly individuals, or those with weakened immune systems who may be more vulnerable to infection.

• Avoid sharing personal items such as towels, washcloths, pillows, eye makeup, or eye drops
• Change pillowcases and bed linens frequently - ideally daily while symptoms are present
• Use separate towels for each family member and wash them after each use
• Disinfect commonly touched surfaces including doorknobs, light switches, remote controls, and phone screens
• Avoid eye makeup until the infection clears, and discard any makeup used during the infection
• Wash hands before and after administering any eye drops or cleaning the eyes

Can Children with Conjunctivitis Go to School or Daycare?

The decision about whether a child with conjunctivitis can attend school or daycare depends on the type of infection and severity of symptoms. Because conjunctivitis spreads easily among children who play and interact closely, guidelines exist to help prevent outbreaks in childcare settings.

Children with significant discharge (lots of pus or very sticky eyes) should stay home because they are most contagious during this period. The combination of frequent eye rubbing and touching toys or other children creates many opportunities for transmission. These children can return when the heavy discharge has resolved, which typically occurs after about 2 days of antibiotic treatment for bacterial conjunctivitis.

Children with mild symptoms (slightly red eyes, minimal discharge in the morning only) who otherwise feel well may be able to attend school or daycare, though policies vary by institution. Some schools require a doctor's note or completion of antibiotic treatment before return. Children with allergic conjunctivitis do not need to stay home because this type is not contagious.

How Is Conjunctivitis Treated?

Treatment depends on the cause: viral conjunctivitis typically resolves without medication in 7-14 days with supportive care. Bacterial conjunctivitis may be treated with antibiotic eye drops or ointment. Allergic conjunctivitis responds to antihistamine eye drops and avoiding allergens. Lubricating eye drops help all types.

The treatment approach for conjunctivitis depends primarily on identifying and addressing the underlying cause. While the symptoms of different types may appear similar, the treatments differ significantly. Proper diagnosis by a healthcare provider ensures you receive appropriate treatment and don't waste time and money on ineffective therapies.

Viral conjunctivitis is the most common form and does not respond to antibiotics, despite the common misconception that all "pink eye" requires antibiotic treatment. Like the common cold, viral conjunctivitis must run its course, which typically takes 7-14 days. Treatment focuses on relieving symptoms through cool compresses, artificial tears, and proper hygiene. Some severe viral infections, particularly those caused by herpes simplex virus, may require antiviral medications prescribed by a doctor.

Bacterial conjunctivitis often improves without antibiotic treatment within 1-2 weeks. However, healthcare providers may prescribe antibiotic eye drops or ointment to speed healing and reduce the risk of complications, particularly in more severe cases. Common antibiotic options include erythromycin ointment, tobramycin drops, and fluoroquinolone drops. After 24-48 hours of antibiotic treatment, bacterial conjunctivitis is generally no longer contagious.

Allergic conjunctivitis treatment focuses on avoiding known allergens when possible and using medications to control symptoms. Over-the-counter antihistamine eye drops provide relief for many people, while more severe cases may benefit from prescription medications including mast cell stabilizers, stronger antihistamines, or short courses of corticosteroid eye drops. Oral antihistamines can also help, especially when eye symptoms accompany other allergic symptoms like sneezing and runny nose.

When Are Antibiotics Necessary?

Many people assume that all cases of conjunctivitis require antibiotics, but this is not accurate. Antibiotics are only effective against bacterial infections and have no effect on viral or allergic conjunctivitis. Using antibiotics unnecessarily contributes to antibiotic resistance and can cause side effects without providing benefit.

Your healthcare provider may recommend antibiotic treatment for conjunctivitis if you have symptoms strongly suggesting bacterial infection (thick, purulent discharge), if you are a contact lens wearer (higher risk of complications), if your immune system is weakened, or if symptoms have not improved after several days of home care. Always complete the full course of antibiotic treatment as prescribed, even if symptoms improve quickly, to ensure the infection is fully cleared.

Frequently Asked Questions