Optometrists examine, diagnose, treat, manage, and prevent diseases/disorders of the eye, and prescribe and dispense eyeglasses/contact lenses.
Chiropractors diagnose and treat disorders of the neuromusculoskeletal system with manipulation and other techniques, and provide holistic health care.
Osteopathic physicians diagnose, treat, and prescribe for patients' medical, surgical, and obstetrical problems. Their training includes an emphasis on the use of the musculoskeletal system in restoring health.
Naturopathic doctors diagnose, treat and prevent diseases/disorders using natural non-invasive therapies and hands-on techniques such as acupuncture/Asian medicine, botanical (herbal) medicine, clinical nutrition, homeopathic medicine, physical medicine, and lifestyle counselling.