This is among the most common forms of endophthalmitis. Most cases are associated with bacterial pathogens, and 75% develop within the first week after cataract surgery. Patients usually present with vision loss (95%), red eyes (80%), and pain (75%). Fever is not present. The source is usually the individual’s skin, lid, and ocular flora. Approximately 30% of cases are culture-negative. In 95% of culture-positive patients, gram-negative cocci are detected. In approximately 70% of these, the isolated coagulase-negative staphylococci are consistent with samples obtained from the patient’s skin and lid margin. Some cases also occur due to using a contaminated surgical solution or material. An example of this is viscoelastic contaminated with Fusarium oxysporum (Fig. 32.1).