Conjunctivitis, commonly referred to as pink eye, refers to an inflammation of the delicate, protective, mucosal, layer of the inside of the eyelid and covering part of the globe itself. The etiologies of conjunctivitis are widely variable. Reliable data are not available regarding prevalence and incidence of the condition, it is widely accepted that conjunctivitis has a significant impact not only on patients and families, in terms of lost time at school and work, but also a substantial cost to healthcare systems. Cost extend beyond recognizing and treating the condition to include imprecise diagnosis, lack of healthcare policy, undue burden of healthcare visits, and a failure to use antibiotics judiciously. This chapter will focus on the infectious causes of conjunctivitis and its consequences, ranging from minor inconveniences to permanent visual impairment, infertility, and even fatal complications.