They also arrange for hospital admission and laboratory services. Some assistants handle billing and bookkeeping. The size of the office determines how much time assistants spend on clerical duties. In larger offices, assistants spend only a little time on clerical work. Assistants are supervised by doctors, other health workers, or office managers.
Some medical assistants specialize.
For example, ophthalmic assistants have extra duties related to eye care. They may do basic eye tests and teach people how to use contact lenses. Medical Assistants is in the Health Services Career Cluster.