An ophthalmologist is a medical doctor who is able to treat complicated eye problems with surgery or other procedures. Ophthalmologists attend medical school. After that, they have a 1-year internship and a residency of 3 years. That's sometimes followed by a fellowship of 1-2 years. These eye doctors offer complete eye care services like eye exams for conditions like glaucoma, iritis, and chemical burns; Surgical eye care, for trauma, crossed eyes, cataracts, glaucoma, and other problems; Diagnosis and treatment of eye conditions related to other diseases, like diabetes or arthritis; Plastic surgery, to raise droopy eyelids or smooth out wrinkles.

Source: WebMD