Optometrists are the primary health care providers for the eye and visual system. They are not surgeons but may refer patients for surgical care when needed. Optometrists examine, diagnose and medically treat eye diseases, injuries, and disorders of the visual system as well as identify related systemic conditions affecting the eye. Some optometrists specialize in work with the elderly, children, or partially sighted persons who need specialized visual devices. Others develop and implement ways to protect workers eyes from on-the-job strain or injury. Some specialize in contact lenses, sports vision,or vision therapy. A few teach optometry, perform research, and consult.

Most countries have regulations concerning optometry education and practice. Often, optometrists are required to participate in ongoing continuing education courses to stay current on the latest standards of care.