The conjunctiva is a thin membrane covering the inside of the eyelids and the white part of the eye (the sclera). Inflammation or infection of the conjunctiva is called conjunctivitis (“pink eye”). It can be caused by viruses, bacteria, or fungi; allergy; exposure to chemicals or irritants; or long-term presence of a foreign body, such as hard or rigid contact lenses.
Viruses causing the common cold can also result in conjunctivitis. The time course for viral conjunctivitis is similar to that of upper respiratory tract infections, with the worst symptoms occurring at 3 to 5 days and resolving in 7 to 14 days. Bacterial conjunctivitis is usually caused by Streptococcus or Staphylococcus. These bacteria live on human skin and can contaminate eye makeup or other products. Less commonly, chlamydia or gonorrhea infections can cause conjunctivitis. Bacterial conjunctivitis usually resolves in 2 to 5 days without treatment but may need topical antibiotics (eye drops or ointment). These types of infectious conjunctivitis are very contagious and easily spread between people.
Signs and symptoms of conjunctivitis
- Sensitivity to light
- Gritty sensation, itchiness, or burning
- Swollen eyelids
- Increased tears
If symptoms do not resolve within the expected time frame, if you have a weakened immune system, or if any of the following symptoms are encountered, you should seek immediate medical attention.
- Moderate to severe eye pain or light sensitivity
- Decreased vision, blurred vision, or double vision that does not resolve after removing discharge from the eyes
- Increased redness of the eyes
If someone has a cold or respiratory symptoms, conjunctivitis is likely caused by the same respiratory virus. Herpes conjunctivitis can occur when there are herpes-like blisters elsewhere on the body. Bacterial conjunctivitis may cause thick yellow-green discharge. Watery discharge is more common with viruses.Treatment and prevention
Over-the-counter artificial tears may relieve symptoms. Antibiotics will not treat viral conjunctivitis; some types, such as those caused by herpes, may need antiviral medication. Bacterial conjunctivitis may get better without treatment, but topical antibiotics may shorten the illness.
To prevent spreading conjunctivitis, wash your hands or use an alcohol-based cleanser, avoid touching and rubbing your eyes, and wash discharge from around the eyes several times a day. Do not share washcloths, towels, makeup, or eyeglasses. Patients are often kept from school or work until there is no discharge or antibiotic therapy has been started.