Viral conjunctivitis treatment. Viruses are the most common cause of pink eye, and also the most contagious; spread by coughing and sneezing. The same viruses that cause the common cold tend to also cause pink eye. This type of infection often affects both eyes, and typically causes the eyes to become itchy and watery, lasting anywhere from 1 to 2 weeks. There is no medical treatment for viral conjunctivitis; the virus must run its course as is the case with a common cold. You may get some relief from symptoms by applying a cold wet washcloth over your eyes.