Conjunctivitis, also known as pink eye, occurs when the lining of the eyelids and the covering of the eye itself becomes infected. If the infectious agent is a virus, the diagnosis will be viral conjunctivitis. Other causes of conjunctivitis include bacteria, allergens and physical irritants. The symptoms of viral conjunctivitis include watery eyes, a red color to the cornea, irritation and sensitivity to bright light. In some cases, a patient may develop blurry vision that can become permanent if the eyes become damaged during the infection.
Adenoviruses
According to American Family Physician, adenoviruses are the most common cause of viral conjunctivitis. There are several subtypes, or serotypes, of adenovirus that can cause pink eye. Adenoviruses typically incubate for five to 12 days before symptoms develop and these viruses are easily spread from one eye to the other. An infection typically lasts one to three weeks. Adenoviruses are highly contagious and can be transmitted via objects that have come in contact with viral particles such as shared makeup or towels, direct contact with infected bodily fluids or even through shared use of a swimming pool with an infected individual. Corticosteroid ointment or eye drops may help patients who experience blurry vision as a result of an adenovirus infection.
Herpes Simplex
Viral conjunctivitis as a result of herpes simplex often happens when a newborn is infected during passage through the birth canal of a mother with an active genital herpes infection. It may also occur if someone touches an open herpes lesion and then touches the eye. Like all herpes infections, an infection of the eye can recur many times throughout the lifetime of the individual. Treatment of an active herpes infection causing conjunctivitis can be treated using antiviral medications such as acyclovir taken orally or through an IV. Unlike an adenoviral infection, herpes infection of the eye cannot be treated using corticosteroids and their use may actually damage the eye. Conjunctivitis as a result of a herpes infection is particularly of concern in immunocompromised individuals, such as people with AIDS.
Enteroviruses
Conjunctivitis caused by the entoviruses coxsackievirus and entovirus 70 may sometimes induces excessive bleeding, or hemorrhaging, from the infected eye according to Archives of Virology. Someone who contracts an enterovirus typically starts to exhibit symptoms within 24 hours. The incidence of hemorrhaging during enterovirus-caused conjunctivitis varies between outbreaks, sometimes being present in almost all cases of a particular outbreak and other times being present in as few as six percent of people who contract the enterovirus.
