Conjunctivitis

Overview

Conjunctivitis is inflammation of the conjunctiva, the thin, clear tissue that covers the white part of the eye and the inside of the eyelids. It is commonly known as “pink eye” because the affected eye may look red or pink. Conjunctivitis can affect one eye or both eyes, and it may occur in people of any age.

Most cases are not serious, but conjunctivitis can be uncomfortable and may spread easily depending on the cause. Some forms improve on their own, while others need medical assessment and treatment. Because red eyes can also be caused by other eye conditions, an eye examination is important if symptoms are severe, persistent, or associated with pain or vision changes.

Symptoms

Symptoms can vary depending on the type of conjunctivitis and the underlying cause. Common signs and symptoms include:

• Redness in one or both eyes
• Watery eyes or increased tearing
• Itching, burning, or a gritty feeling, as if something is in the eye
• Discharge from the eye, which may be watery, sticky, or thick
• Crusting of the eyelids or eyelashes, especially after sleep
• Mild swelling of the eyelids
• Sensitivity to light in some cases
• Temporary blurred vision due to discharge or tearing

Allergic conjunctivitis often causes intense itching and affects both eyes. Viral conjunctivitis commonly causes watery discharge and may occur with cold-like symptoms. Bacterial conjunctivitis may cause thicker discharge and eyelid crusting. However, symptoms can overlap, so it is not always possible to know the cause without medical evaluation.

Causes and Risk Factors

Conjunctivitis has several possible causes. The main types include infectious conjunctivitis, allergic conjunctivitis, and irritant-related conjunctivitis.

Infectious conjunctivitis may be caused by viruses or bacteria. Viral conjunctivitis is often linked to respiratory infections and can spread through close contact, contaminated hands, towels, cosmetics, or surfaces. Bacterial conjunctivitis can also spread through direct contact with eye secretions or contaminated items.

Allergic conjunctivitis occurs when the eyes react to allergens such as pollen, dust, mold, animal dander, or certain environmental triggers. It is not contagious. Irritant conjunctivitis may occur after exposure to smoke, pollution, chlorine in swimming pools, cosmetics, or chemicals.

Risk factors for conjunctivitis include close contact with someone who has an eye infection, poor hand hygiene, touching or rubbing the eyes, wearing contact lenses, exposure to allergens or irritants, and using contaminated eye makeup or shared personal items. People with dry eyes or other surface eye problems may also be more prone to irritation and inflammation.

Diagnosis

Diagnosis usually begins with a discussion of symptoms, recent exposure to people with eye infections, allergy history, contact lens use, and any eye injury or chemical exposure. An ophthalmologist or healthcare professional will examine the eye and eyelids, checking the pattern of redness, the type of discharge, and whether vision is affected.

In many cases, conjunctivitis can be identified through a clinical eye examination. Additional tests are not always needed. If symptoms are severe, recurrent, unusual, or not improving as expected, a sample of eye discharge may be taken for laboratory analysis. This can help identify the cause and guide treatment in selected cases.

It is important to distinguish conjunctivitis from other eye conditions that may look similar, such as inflammation inside the eye, corneal infection, foreign body injury, or glaucoma-related problems. This is especially important when there is eye pain, significant light sensitivity, reduced vision, or a history of contact lens use.

Treatment Options

Treatment depends on the cause and severity of conjunctivitis. The goal is to relieve discomfort, reduce inflammation, prevent spread when contagious, and protect the surface of the eye.

Viral conjunctivitis often improves with supportive care, such as maintaining eye hygiene and using comfort measures recommended by a healthcare professional. Because it can be contagious, careful handwashing and avoiding shared towels, cosmetics, and close face-to-face contact are important until advised otherwise.

Bacterial conjunctivitis may require prescription eye treatment, depending on the findings and the patient’s age, symptoms, and risk factors. It is important not to use leftover eye medicines or someone else’s medication, as the cause may be different and inappropriate treatment can delay recovery or irritate the eye.

Allergic conjunctivitis is managed by reducing exposure to triggers when possible and using treatments that calm the allergic response, as recommended by a healthcare professional. Irritant conjunctivitis usually involves removing or avoiding the irritant and assessing the eye, especially if chemical exposure has occurred.

Contact lens wearers should seek medical advice before continuing lens use when conjunctivitis symptoms appear. Lenses and related supplies may need to be checked or replaced to reduce the risk of reinfection or corneal complications.

Good hygiene helps limit spread and irritation. Patients are generally advised to avoid touching the eyes, wash hands frequently, avoid sharing personal items, and replace or avoid using eye makeup during an active episode. Specific guidance should come from an eye care professional based on the individual situation.

When to See a Doctor

Medical evaluation is recommended if eye redness or discharge does not improve, keeps returning, or is associated with other concerning symptoms. Seek prompt medical care if any of the following occur:

• Moderate or severe eye pain
• Blurred or reduced vision that does not clear with blinking
• Marked sensitivity to light
• Severe swelling around the eye
• Symptoms after an eye injury or chemical exposure
• Conjunctivitis in a newborn or very young infant
• Symptoms in a person who wears contact lenses
• A weakened immune system or recent eye surgery
• Worsening symptoms despite basic hygiene measures

Conjunctivitis is often manageable, but the right approach depends on the cause. An ophthalmology assessment can help confirm the diagnosis, exclude more serious eye problems, and recommend safe, appropriate care.