The American Optometric Association is the leading authority on quality care and an advocate for our nation's health, representing more than 44,000 doctors of optometry (O.D.), optometric professionals, and optometry students. Doctors of optometry take a leading role in patient care with respect to eye and vision care, as well as general health and well-being. As primary health care providers, doctors of optometry have extensive, ongoing training to examine, diagnose, treat and manage ocular disorders, diseases and injuries and ocular manifestations of systemic diseases. Doctors of optometry provide more than two-thirds of primary eye care in the U.S.