Ophthalmology is a branch of medicine and surgery which deals with the diagnosis and treatment of eye disorders. An ophthalmologist is a specialist in ophthalmology. The credentials include a degree in medicine, followed by additional four to five years of ophthalmology residency training. Ophthalmology residency training programs may require a one-year pre-residency training in internal medicine, pediatrics, or general surgery. Additional specialty training (or fellowship) may be sought in a particular aspect of eye pathology. Ophthalmologists are allowed to use medications to treat eye diseases, implement laser therapy, and perform surgery when needed. Ophthalmologists may participate in academic research on the diagnosis and treatment for eye disorders.  An ophthalmologist is a medical or osteopathic doctor who specializes in eye and vision care. Ophthalmologists complete 12 to 13 years of training and education, and are licensed to practice medicine and surgery. This advanced training allows ophthalmologists to diagnose and treat a wider range of conditions than optometrists and opticians. Typical training includes a four-year college degree followed by at least eight years of additional medical training. An ophthalmologist diagnoses and treats all eye diseases, performs eye surgery and prescribes and fits eyeglasses and contact lenses to correct vision problems. Many ophthalmologists are also involved in scientific research on the causes and cures for eye diseases and vision disorders. Because they are medical doctors, ophthalmologists can sometimes recognize other health problems that aren't directly related to the eye, and refer those patients to the right medical doctors for treatment. A general practice doctor may refer someone to an ophthalmologist if they show symptoms of cataracts, eye infections, optic nerve problems, or other eye conditions. In this article, we look at what ophthalmologists do, including the types of conditions that they treat, the procedures they perform, and when a person might see this specialist. Subspecialist ophthalmologists have usually completed training that allows them to work on eye conditions that are complex, involve a specific part of the eye, or affect certain groups of people. They also train more extensively than regular ophthalmologists to perform extremely intricate surgeries on delicate parts of the eye. Aside from caring for the eyes and vision, an ophthalmologist’s medical training may also equip them to notice symptoms of conditions that do not directly relate to the eye. In such cases, they can refer people for the appropriate treatment. Many ophthalmologists also participate in some form of scientific research focusing on the causes of eye and vision conditions, as well as potential cures. While ophthalmologists are trained to care for all eye problems and conditions, some ophthalmologists specialize further in a specific area of medical or surgical eye care. This person is called a subspecialist. He or she usually completes one or two years of additional, more in-depth training (called a Fellowship) in one of the main subspecialty areas such as Glaucoma, Retina, Cornea, Pediatrics, Neurology, Oculo-Plastic Surgery or others. This added training and knowledge prepares an ophthalmologist to take care of more complex or specific conditions in certain areas of the eye or in certain groups of patients.