Pinkeye, also known as conjunctivitis, has several different causes, according to WebMD. Common causes include viruses and bacteria such as gonorrhea or chlamydia. Irritants in the eye such as dirt, smoke and shampoo as well as allergies such as dust or pollen can also cause pinkeye.
Most pinkeye is self-inflicted and not contagious, but pinkeye caused by bacteria or viruses can easily spread from person to person, according to WebMD. Although contagious, it is not a serious health condition in adults. When a newborn baby contracts pinkeye, they should seek medical attention right away, as this type of infection can threaten an infant’s vision. In newborns, a blocked tear duct is typically at the root of pinkeye, according to Mayo Clinic.
Pinkeye is defined as an inflammation of the conjunctiva or the thin tissue that covers the eye and the inside of the eyelid, states WebMD. Pinkeye caused by viruses typically produces a watery discharge, while bacterial pinkeye produces a thick, yellow-green discharge, according to Mayo Clinic.
When the conjunctiva is irritated from a chemical splash, irritant or foreign object, the eye may water or produce a mucous-like discharge, according to WebMD. Typically, this type of pinkeye clears up on its own in a day. Pinkeye from allergies typically impacts both eyes and causes itching, tearing and inflammation as well as nasal discharge.