The diagnosis at first visit was corneal ulcer with secondary uveitis from CL overwear OD. This was determined mainly from the patient’s report of sud- den onset redness and pain after fall- ing asleep in her CLs along with the presence and location of a paracentral circumscribed corneal infiltrate with stromal excavation producing positive staining. Other differentials were con- sidered and ruled out. For instance, herpes simplex was ruled out because fluorescein staining did not show a typ- ical dendritic pattern. Fungal keratitis was ruled out because the patient de- nied any recent ocular trauma and the lesion did not present a feathery bor- der. Acanthamoeba keratitis was ruled- out because the patient did not swim in her CLs and did not recently travel to a warm and moist environment. The process of clinical decision-making in- volves justification of diagnosis as well as ruling out other potential diagnoses.