Conjunctivitis is an inflammation of the conjunctiva, a membrane that lines the inside of the eyelid and touches the white part of the eye, secreting a mucous that lubricates the eyeballs.

There are many different causes of conjunctivitis. The main causes are the following:

• Infectious : resulting from bacterial or viral infections.
• Noninfectious : due to certain allergies (such as pollen or animal dander ) and chemical irritants (such as smoke, preservatives in contact lens solutions and some eye drops, or the chlorine in swimming pools). Allergic Conjunctivitis is usually accompanied by intense symptoms (itching, redness, tearing, and swelling of the eye membranes). It is frequently seasonal, and is accompanied by other typical allergic symptoms such as sneezing, itchy nose, or scratchy throat. Cold moist wash clothes applied to the eyes and over-the-counter decongestant eye drops often provide relief.

See also : Sinusitis ; Rhinoconjunctivitis ; Rhinitis .