An ophthalmologist is a medical doctor (M.D.) uniquely trained to diagnose and treat all disorders of the eye. An ophthalmologist is qualified to perform surgery, prescribe and adjust eyeglasses and contact lenses, and prescribe medication.
An optometrist (O.D.) is not a medical doctor but is specially trained to diagnose eye abnormalities and prescribe, supply, and adjust eyeglasses and contact lenses. An optician fits, supplies, and adjusts eyeglasses and contact lenses. An optician cannot examine the eyes or prescribe eyeglasses or medication.