Microscopes are of great importance to the field of medicine for several reasons. First, microscopes are used to identify cells in a sample. This is especially important when identifying the cause of an infection, as analyzing a sample could reveal a bacterial, fungal, or viral source for an illness. Microscopic analysis can also identify cellular issues like sickle-cell anemia or various types of cancer. In fact, the physical features of cancer cells determine the type of cancer and can indicate the best way to treat the patient. Beyond diagnostic purposes, microscopes are also vital in identifying how various chemical substances affect living tissues, abnormal cells, and infectious agents. This observation helps in the development of new medicines.