What kind of doctor is an ophthalmologist?

To answer this question, it is important to distinguish between an optometrist and an ophthalmologist as people often confuse the two. An ophthalmologist is a fully qualified medical Doctor Who focuses on the eye. An optometrist is not a medical doctor, but does receive several years of specialized training on the eye, prescribing prescription eyeglasses/contacts and diagnosing eye disorders.

Legally, an ophthalmologist can do everything an optometrist can do although in practice day-to-day eye care is typically left to optometrists while ophthalmologists focus more on surgery, prescribing medication and treating more complex eye conditions. Both are an important part of the US healthcare system.

As for whether an optometrist is "called doctor," it depends on the country. In most countries an optometrist is not addressed as "doctor," this title being reserved primarily for medical doctors and those with PhDs. Within the US, the profession has made a particular point about wanting to be addressed as "doctor" and it has become broadly accepted convention to refer to optometrists as such.