What Is an Ophthalmologist and What Do They Do?

An ophthalmologist is a physician who specializes in vision, medical, and surgical care of the eyes. They can perform eye exams, dispense medications, prescribe corrective lenses (like eyeglasses or contacts), and perform eye surgery.

Ophthalmologists are the only healthcare providers trained to provide comprehensive diagnosis and treatment of eye disorders. Ophthalmologists are often confused with optometrists (who treat certain eye disorders but do not perform surgery) and opticians (who design, fit, and dispense corrective lenses).

This article describes some of an ophthalmologist's concentrations, as well as the expertise they must have with equipment and treatments. It also points out some of the subspecialties they have to choose from and the training they must undergo before they can work in the field.

What Do Ophthalmologists Do?

Ophthalmology is a clinical and surgical specialty that is focused on the diagnosis and treatment of eye disorders and diseases.

Ophthalmologists are trained to perform a variety of tasks, such as:

• Performing eye exams
• Prescribing eyeglasses and contact lenses
• Prescribing medications to alleviate eye symptoms or treat eye disease
• Performing laser eye procedure
• Performing eye surgery when needed
• Participating in academic research

Ophthalmologists often work with other specialists when vision loss is secondary to another medical condition, such as diabetes.

What Conditions Do Ophthalmologists Treat?

Ophthalmologists are trained to diagnose and treat a wide range of conditions, including:

• Amblyopia, also known as lazy eye
• Astigmatism, blurring of vision caused by an irregular cornea
• Cataract, clouding of the lens of the eye
• Conjunctivitis, also known as "pink eye"
• Detached retina, the detachment of tissues at the back of the eye
• Eye cancer, most commonly basal cell carcinoma
• Eye occlusion, sometimes called "eye stroke"
• Fuchs dystrophy, clouding of the cornea
• Glaucoma, loss of vision often due to elevated eye pressure
• Hyperopia, also known as farsightedness
• Macular degeneration, an aging-related loss of vision
• Macular dystrophy, an inherited disorder causing central vision loss
• Myopia, also known as nearsightedness
• Ptosis, drooping of one or both eyelids
• Tear duct obstruction
• Traumatic eye injury

What Tests Do Ophthalmologists Perform?

An ophthalmologist typically works in an office outfitted with equipment for eye exams. More complex imaging or exploratory tests may be conducted in a hospital or medical facility.

While some eye surgeries can be performed in a healthcare provider's office, others may require an operating room in a hospital.

Eye Examination

An eye exam consists of a series of tests that assess the state of someone's vision and their ability to focus on and discern objects. The basic test includes:

• Visual acuity exam, using an eye chart or other tools to evaluate how a patient's vision compares to the standard definition of normal vision (20/20 vision)
• Refraction testing, using equipment that measures how light bends when it passes through the lens
• Pupil function exam, which evaluates the pupil's shape, size, and reaction to light (often with a swinging-flashlight test used to assess the optic nerve response)
• Ocular motility testing, which measures the strength of eye muscles, typically by asking the patient to follow the healthcare provider's finger with the eyes
• Visual field testing, which examines peripheral vision by asking the patient to count the number of fingers held outside of their central field of vision
• Slit lamp testing, using a table-mounted microscope to view the interior of the eye as a small beam of light is directed through the pupil
  

Specialized Tests

In addition to a basic eye exam, an ophthalmologist may order specialized tests and imaging studies. Examples include:

• Applanation tonometry, a technique using a tonometer to measure the amount of pressure needed to flatten the cornea
• Corneal topography, in which a topographic map of the cornea is created using a noninvasive computerized imaging device
• Eye ultrasonography, a noninvasive imaging technique that uses high-frequency sound waves to form a live image of the inner eye
• Fluorescein angiography, which uses a fluorescent dye and a specialized camera to evaluate blood circulation in the eye
• Optical coherence tomography, an imaging technique that uses light waves to create two- and three-dimensional images of the internal eye
  

Treatments

There are many different drugs used in ophthalmology, including eye drops, eye injections, implanted eye pellets, and oral medications, In addition to medications, an ophthalmologist can prescribe corrective lenses (including bifocal, multifocal, and progressive eyeglasses) and contacts.

Unlike optometrists, ophthalmologists can perform more sophisticated medical procedures and surgeries. Some of the more common ones include:

• Cataract surgery, in which a cloudy lens is replaced with an artificial one
• Corneal transplant, in which diseased or scarred corneal tissue is replaced with healthy tissue from an organ donor
• Enucleation with eye prosthesis, the removal of a diseased or damaged eye followed by the insertion of an artificial, nonfunctioning eye
• Glaucoma surgery, using lasers or standard surgical tools to increase fluid outflow from the iris or to remove a portion of the iris
• LASIK eye surgery, used to correct errors of refraction, reducing or eliminating the need for corrective lenses
• Strabismus surgery, used to adjust eye muscles to straighten misaligned eyes
• Vitrectomy, a procedure that removes the vitreous humor, a gel-like substance in the eye, to correct vision problems

Training and Certification

An ophthalmologist is a medical doctor (MD) or an osteopathic doctor (DO). The pathway to becoming an ophthalmologist takes between 11 and 12 years.

To enter medical school, a bachelor's degree is first required, followed by completion of pre-medicine studies (including advanced math, science, and biology), and then taking the Medical Competency Aptitude Test (MCAT).

Medical school follows, with two years of classroom studies and two years of clinical rotations in different medical facilities.

Upon graduation, ophthalmologists obtain a medical license in the state in which they intend to practice. This usually involves passing the U.S. Medical Licensing Examination (USMLE) if they are an MD or the Comprehensive Osteopathic Medicine Licensing Examination (COMLEX) if they are a DO. Some states also require that ophthalmologists pass a state exam.

An internship and residency follow medical school. This step in the process can last between three and eight years.

Upon completion of their residency, ophthalmologists can obtain board certification by passing a written and oral exam administered by the American Board of Ophthalmology (ABO). The certification is valid for 10 years, during which time they must take regular continuing medical education (CME) courses to be eligible for recertification.

Subspecialties

Some ophthalmologists will embark on further fellowship training to specialize in specific areas of ophthalmology, including:

• Cataract and refractive surgery, specializing in corrective vision surgery
• Neuro-ophthalmology, specializing in the brain and optic nerve
• Ocular pathology, specializing in the diagnosis of eye disease
• Oculoplastics, specializing in the reconstruction of the eyelid, orbit, and tear ducts
• Pediatric ophthalmology, specializing in the treatment of children
• Vitreoretinal diseases, specializing in the retina or vitreous humor
  

What's the Difference Between an Optometrist and an Ophthalmologist?

Ophthalmologists are often confused with other medical professionals who provide eye care. Some are healthcare providers while others are non-clinical allied health professionals.

Among them:

• Optometrists are healthcare providers who can diagnose and treat many eye conditions but are not trained in surgery or laser procedures. Optometrists are not considered physicians because they do not attend medical school; instead, they hold a Doctor of Optometry (DO) degree, which requires four years of optometry school after earning a bachelor's degree.
• Orthoptists, sometimes called eye physical therapists, are allied health professionals who evaluate and manage childhood and adult eye alignment problems. Certification from the American Orthoptic Council (AOC) is available for those who complete attending a two-year accredited program after obtaining a bachelor’s degree.
• Opticians are technicians who fit eyeglasses, contact lenses, and other corrective devices by filling a prescription from an optometrist or ophthalmologist. Opticians can practice after one- to two-year training at a technical school or college with an accredited opticianry program. Certification can be obtained from the American Board of Opticianry (ABO).
  

When Should You See an Ophthalmologist?

You should see an ophthalmologist if you experience any of the following symptoms, particularly if they are persistent, unexplained, or worsening:

• Eye pain
• Changes in vision
• New eye floaters
• Dry eyes with itching or burning
• Seeing flashes of light, halos, spots, or ghost-like images
• Seeing lines and edges that appear distorted or wavy
• Eye redness
• Eye tearing or discharge
• Eye bulging
• Diplopia, also known as double vision
• Esotropia, also known as crossed eyes

There are other reasons why you may need to seek urgent or ongoing care from an ophthalmologist, even if vision problems are currently mild.

Among them:

• Diabetes can lead to vision loss as high blood sugar damages blood vessels at the back of the eye, leading to diabetic retinopathy. People with diabetes need to have an annual eye exam.
• Uncontrolled high blood pressure is a major contributing factor to macular degeneration, one of the leading causes of vision loss in older adults. Any vision changes warrant a visit.
• A family history of glaucoma and cataracts can increase the risk of these diseases, warranting an annual check-up if you experience vision changes.
• Advanced HIV is associated with opportunistic infections, like cytomegalovirus (CMV) retinitis, that cause vision loss. Eye exams are advised for people with HIV who are immunocompromised.
• Herpes zoster ophthalmicus occurs when shingles affect the trigeminal cranial nerve of the face and occasionally the optic nerve. Vision changes with shingles warrant an investigation.
• Herpes simplex keratitis, also known as eye herpes, almost invariably requires treatment by an ophthalmologist.
  

Summary

Ophthalmologists are medical specialists who diagnose and treat eye diseases and other problems involving the eyes. Unlike optometrists, ophthalmologists are physicians with a Doctor of Medicine (MD) or Doctor of Osteopathic Medicine (DO) degree who can perform eye surgery and laser eye procedures like LASIK.