An optometrist is a doctor of optometry (O.D.) and is licensed to practice optometry, not medicine. The practice of optometry traditionally involves examining the eye for the purpose of prescribing and dispensing corrective lenses, screening vision to detect certain eye abnormalities, and prescribing medications for certain eye diseases. An ophthalmologist is an eye doctor -- either a medical or an osteopathic doctor who specializes in eye and vision care. Ophthalmologists are specially trained to provide the full spectrum of eye care, from prescribing glasses and contact lenses to treating eye diseases and injuries and performing complex and delicate eye surgery. Many ophthalmologists are also involved in scientific research into the causes and cures for eye diseases and vision problems. An ophthalmologist is the only professional who can treat it all: eye diseases, injuries, and eye surgery.