An ophthalmologist (MD) has a medical degree and is licensed to practice medicine and perform eye surgery. An ophthalmologist is qualified to diagnose and treat all eye diseases. An optometrist (OD) has a degree in optometry and is qualified to determine the need for glasses and contact lenses, prescribe optical correction, and screen for some eye conditions. An optometrist cannot perform eye surgery. An optician is trained to fit and dispense eyeglasses or contact lenses based upon a prescription from a licensed ophthalmologist or optometrist.