According to WebMD, pink eye is caused by viral or bacterial infections, dry eyes, allergic reactions, or exposure to chemicals. EMedTV explains that in some bacterial cases, those with chlamydia or gonorrhea can spread the infection to the eyes and cause pink eye.
Pink eye that is caused by a virus or bacteria is extremely contagious and typically spreads due to the lack of proper hand washing, explains WebMD. All About Vision states that the most common cause of pink eye is a viral infection, similar to the common cold. Pink eye, medically known as conjunctivitis, is defined by WebMD as the swelling of the mucous membrane that lines the eyes and the eyelids. Symptoms of viral pink eye may include redness of the eye, itching or burning eyes, swollen eyelids and an increase of tears. Often, pink eye also causes a clear or white-colored liquid to leak from the eyes that may harden, making it difficult to open the eyes. Those suffering from bacterial pink eye may notice the same symptoms as viral pink eye and have mild pain as well, according to WebMD. All About Vision adds that in most cases, viral pink eye does not require medical treatment and takes a few days to run its course. However, bacterial pink eye is treated with prescription medication.