Two important distinctions are evident in these definitions. First, ophthalmologists are medical doctors and have attended medical school and specialize in surgical care of the eye, while optometrists are doctors of optometry who have attended optometry school and specialize in the general care of the eye and vision. Second, ophthalmologists are responsible for surgical treatment or diseases and disorders. Optometrists "provide comprehensive eye and vision care, which includes refraction and detection/diagnosis and management of disease in the eye" with limited surgical involvement.

There are also important similarities. Both optometrists and ophthalmologists treat patients with medications and optical aids. Both perform screenings for common ocular problems affecting children (such as amblyopia and strabismus) and the adult population (such as cataracts, glaucoma, and diabetic retinopathy). Optometrists usually refer to ophthalmologists for further assessment for surgical treatment of ocular diseases. Both are required to participate in ongoing continuing education courses to maintain licensure and stay current on the latest standards of care.