What causes conjunctivitis?
Conjunctivitis may be caused by a virus, an allergic reaction (to dust, pollen, smoke, fumes or chemicals) or, in the case of giant papillary conjunctivitis, a foreign body on the eye, typically a contact lens. Other causes include exposure to infected persons and bacterial and viral infections elsewhere in the body.
Signs and symptoms of conjunctivitis
The hallmark sign of conjunctivitis is a pink or reddish appearance to the eye due to inflammation and dilation of conjunctival blood vessels.
Depending on the type of conjunctivitis, other signs and symptoms may include a yellow or green mucous discharge, watery eyes, itchy eyes, sensitivity to light, and pain.
How can you tell what type of pink eye you have?
- Viral conjunctivitis. Usually causes excessive eye watering and a light discharge.
- Allergic conjunctivitis. Affects both eyes and causes itching and redness in the eyes and sometimes the nose, as well as excessive tearing.
- Bacterial conjunctivitis. Often causes a thick, sticky discharge, sometimes greenish.
- Giant papillary conjunctivitis. Usually affects both eyes and results in contact lens intolerance, itching, a heavy discharge, tearing, and bumps on the underside of the eyelids.