Bacterial colonization of the eyelid and conjunctiva is normal and helps reduce opportunities for pathogenic strains from gaining a foothold. Host defense mechanisms can be overcome and lead to serious ocular morbidity if not treated properly. Although the clinical manifestations of conjunctival and corneal infections may be characteristic of certain pathogens, further laboratory evaluation with cultures and antibiotic susceptibility testing provide a definitive diagnosis and more focused treatment after empirical therapy has been initiated.