Conjunctivitis is the term used to describe inflammation of the conjunctiva—the thin, filmy membrane that covers the inside of your eyelids and the white part of your eye (sclera).
Conjunctivitis is most commonly referred to as red or "pink" eye.
The conjunctiva, which contains tiny blood vessels, produces mucus to coat and lubricate the surface of your eye. When the conjunctiva becomes irritated or inflamed, the blood vessels become larger and more prominent, making your eye appear red.
Symptoms of conjunctivitis include:
Many different sources of eye irritation can cause conjunctivitis. The most common are:
Viral infection is the most common cause of conjunctivitis. This same virus produces the familiar red and watery eyes, sore throat, and runny nose of a common cold. Symptoms of conjunctivitis can last from one to two weeks and then will disappear on their own. Discomfort, however, can be alleviated with warm compresses applied to the eyes.
Bacterial infections, such as staphylococcus or streptococcus, cause a type of red eye that produces considerable amounts of pus.
Some bacterial infections, however, are more chronic and may produce little or no discharge except for some mild crusting of the eyelashes in the morning. Antibiotic eyedrops are typically used to treat bacterial conjunctivitis.
Infectious conjunctivitis, whether bacterial or viral, can be quite contagious. Practicing good hygiene can help prevent the spread of conjunctivitis if you are infected. You should:
Allergic conjunctivitis is not infectious or contagious. It occurs when the body is exposed to materials that cause an allergic reaction, such as pollen or dander, and is often seasonal. Symptoms include redness, itching and/or burning eyes, tearing, enlarged vessels in the sclera (white part of the eye), and puffy eyelids. Treatment often includes applying cool compresses to the eyes and taking antihistamines.
Environmental irritants, such as smoke or fumes, may also cause conjunctivitis. The symptoms are usually similar to those of allergic conjunctivitis.
Generally, conjunctivitis is easily treated. However, if symptoms of conjunctivitis persist for an extended period of time after treatment, you should have your eyes examined by your ophthalmologist (Eye M.D.), as these symptoms may indicate a more serious eye problem. There are several eye diseases that cause red eyes, some of which can lead to blindness unless diagnosed and treated.