Conjunctivitis refers to inflammation of the conjunctiva, which is the thin layer covering the white part of the eye (the sclera).  It is often described with the generic term “pink eye”.  Conjunctivitis can cause watering of the eyes, foreign body sensation, itch, mucous discharge/crusting, blurry vision, and soreness.  There are many causes of conjunctivitis, including viral or bacterial infections, allergies, or exposure to irritants, such as smoke.  Viral conjunctivitis is the most common type, often occurring with a common cold and causing eye discomfort and watering.  There is no treatment for viral infection, but patients may find relief with artificial tears and cold compresses.  Bacterial conjunctivitis is usually distinguished from viral by the significant amount of mucous discharge that accompanies it.  Antibiotic drops or ointment can be prescribed to treat it.  Eye infections, especially viral conjunctivitis, can be highly contagious.  You can help limit the spread of conjunctivitis with frequent hand washing, regular replacement of cosmetics, good contact lens hygiene, and avoiding hand to eye contact.  Allergic conjunctivitis is a non-contagious form of a red eye.  It is usually seasonal and accompanied by itch.  It can be managed with antihistamine eye drops and cold compresses.  You should seek evaluation by your eye care provider should you experience a persistent red eye.