Viral conjunctivitis is often diagnosed based on a person’s history and symptoms. It tends to occur in both eyes and often accompanies a common cold or respiratory tract infection. Laboratory tests usually are not needed to diagnose viral conjunctivitis; however, testing may be done if a more severe form of viral conjunctivitis is suspected. More severe causes include herpes simplex virus (which usually involves blisters on the skin), varicella-zoster virus (chickenpox and shingles), rubella or rubeola (measles). This testing is performed using a sample of the discharge from an infected eye.
Most cases of viral conjunctivitis are mild and will clear up in 7–14 days without treatment and without any long-term consequences. In some cases, however, viral conjunctivitis can take two or more weeks to resolve, especially if complications arise.
Antiviral medication can be prescribed by a physician to treat more serious forms of conjunctivitis, such as those caused by herpes simplex virus or varicella-zoster virus. Antibiotics will not improve viral conjunctivitis as these drugs are not effective against viruses.