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Conjunctivitis (Pink Eye)

Conjunctivitis, commonly known as pink eye, is an infection of the conjunctiva (the outer-most layer of the eye that covers the sclera). The three most common types of conjunctivitis are: viral, allergic and bacterial. Each requires different treatments. With the exception of the allergic type, conjunctivitis is typically contagious.

The viral type is often associated with an upper respiratory tract infection, cold, or sore throat. The allergic type occurs more frequently among those with allergic conditions. When related to allergies, the symptoms are often seasonal. Allergic conjunctivitis may also be caused by intolerance to substances such as cosmetics, perfume, or drugs. Bacteria such as staphylococcus and streptococcus often cause bacterial conjunctivitis. The severity of the infection depends on the type of bacteria involved.

Signs and Symptoms

Viral Conjunctivitis
• Watery discharge
• Irritation
• Red eye
• Can spread to both eyes

Allergic Conjunctivitis
• Usually affects both eyes
• Itching
• Tearing
• Swollen eyelids

Bacterial Conjunctivitis
• Stringy discharge that may cause the lids to stick together, especially after sleeping
• Swelling of the conjunctiva
• Redness
• Tearing
• Irritation and/or a gritty feeling
• Usually affects only one eye, but may spread easily to the fellow eye

Conjunctivitis is diagnosed during a routine eye exam using a slit lamp microscope. In some cases, cultures are taken to determine the type of bacteria causing the infection.

Conjunctivitis requires medical attention. The appropriate treatment depends on the cause of the problem.

For the allergic type, cool compresses and artificial tears sometimes relieve discomfort in mild cases. In more severe cases, non-steroidal anti-inflammatory medications and antihistamines may be prescribed. Some patients with persistent allergic conjunctivitis may also require topical steroid drops.

Bacterial conjunctivitis is usually treated with antibiotic eye drops or ointments that cover a broad range of bacteria.

Like the common cold, there is no cure for viral conjunctivitis; however, the symptoms can be relieved with cool compresses and artificial tears (found in most pharmacies). For the worst cases, topical steroid drops may be prescribed to reduce the discomfort from inflammation. Viral conjunctivitis usually resolves within 3 weeks.

Images and information related to Eye Conditions on this website have been kindly provided courtesy of
St. Luke's Cataract & Laser Institute and adapted for the International Guide Dog Federation website. This on-line information is for educational and communication purposes only and should not be construed as personal medical advice. Information published on this website is not intended to replace, supplant, or augment a consultation with an eye care professional regarding the viewer/user's own medical care. The International Guide Dog Federation disclaims any and all liability for injury or other damages that could result from use of the information obtained from this site