You got me curious Whos. Here's what I found-
http://vision.about.com/od/basiceyehealth/a/righteyedoctor.htm
Ophthalmologists are physicians with medical degrees, designated by an M.D. after their names. This degree typically is bestowed after four years of college, four years of medical school, and four years of training as an intern or resident in a medical facility.
You typically would need an ophthalmologist for surgeries and managing serious eye diseases.
Optometrists usually receive their doctorate degree after four years of college pre-med courses and four years in an accredited optometry college. These individuals have the designation of O.D. (doctor of optometry) after their names.
Depending on state regulations where they are located, optometrists may be able to diagnosis and manage eye diseases as well as administer certain prescriptions. An optometrist often handles routine eye examinations and prescriptions.
Opticians prepare and provide corrective lenses according to prescriptions issued by optometrists and ophthalmologists. Some states have regulations governing qualifications of opticians.
Seek out an optician when you need prescriptions filled for glasses and contact lenses. Opticians also can help you achieve the proper fittings for vision correction lenses.