Inflammation of this membrane is called conjunctivitis. Causes Conjunctivitis is caused by a virus, bacteria or an allergic reaction. Bacterial and viral systemic infections or allergic reactions to dust, pollen, smoke, fumes or chemicals may also result in conjunctivitis. In general, pain, itching and redness on the eye surface accompany inflammation. Viral conjunctivitis usually affects only one eye and causes excessive eye watering and a light discharge.
Bacterial conjunctivitis affects both eyes and causes a heavy discharge.
Allergic conjunctivitis also affects both eyes, and causes itching and redness in the eyes and sometimes the nose, as well as excessive eye watering. Your doctor needs to know whether your conjunctivitis is allergic, bacterial or viral so she can choose the appropriate treatment. A new system called a tear film analysis system can diagnose allergic conjunctivitis definitively. Avoiding the cause of conjunctivitis if possible is the best remedy. While we don't always have success staying away from bacterial and viral infections, avoiding allergic conjunctivitis is much easier.