Optometry is a specialized health care profession that involves examining the eyes and related structures for defects or abnormalities. Optometrists are health care professionals who typically provide comprehensive primary eye care.

In the United States and Canada, optometrists are those that hold a Doctor of Optometry degree. They are trained and licensed to practice medicine for eye related conditions, in addition to providing refractive (optical) eye care. In the United Kingdom, optometrists may also practice medicine (and provide refractive care) for eye related conditions. The Doctor of Optometry title can also be used in the UK for those that hold the postgraduate O.D. degree. Within their scope of practice, optometrists are considered physicians and bill medical insurance(s) (example: Medicare) accordingly. Moreover, many participate in academic research for eye related conditions and disease. Optometrists are the only health care professionals with a first professional degree specific to eye care; ophthalmologists are physicians who typically hold a four-year college degree, a medical degree, and at least three years of residency training after medical school, obviating the need for an eye-specific degree.