Infection is commonly encountered in everyday ophthalmic practice. It is of great importance that all ophthalmic personnel are familiar with the basic etiologies of these infections, and the basic techniques which are used in diagnosis. When evaluating a patient with possible infection, it is often of great help to be familiar with the normal microbial flora of the human body. This normal flora has been detailed in the article. The assumption is that knowledge of a patient's flora can help guide decisions about the possible etiologies of an infection. When presented with an obvious ocular infection, health care personnel should review the "usual suspects"--that is, the common etiologies for each type of infection. The key to combating ocular infections lies in accurate treatment of the presumed infectious agent. Therefore, the techniques and steps used in the identification of the etiology of an infection should be known to all ophthalmic personnel. The proper sterile techniques of obtaining a specimen from a suspected corneal ulcer or conjunctivitis and the plating of the specimen on specific agar for identification are essential to everyday practice (Figure 8). Patients who will undergo surgery, regardless of the type, are being placed at a special risk for infection. These post-operative infections can destroy the work of the most careful and exact surgical technique. It is an essential part of the procedure that the patient be protected as best they can from subsequent infection. The techniques to reduce the risk of post-operative infection have been detailed above. Proper preparation of a sterile field, sterile draping, and perioperative antibiotics can reduce the chance of a subsequent infection. It is important that these basic steps of care be properly provided to help insure successful surgical outcomes and excellence in health care.