An ophthalmologist is a medical professional specializing in eye care. They diagnose and treat conditions that affect the eye. They can also perform eye exams, surgery, and fit eyeglasses and contact lenses.

This article explains what ophthalmologists do and the conditions they treat.

It also looks at how they differ from other healthcare professionals that specialize in eye and vision care.

A patient and an ophthlamologist.Share on Pinterest
FG Trade/Getty Images

Ophthalmologists are medical professionals who are licensed to practice eye medicine and surgery.

An ophthalmologist can:

  • perform eye exams
  • diagnose and treat eye disorders and diseases
  • perform eye surgery
  • prescribe and fit eyeglasses and contact lenses

According to the American College of Surgeons, they are the only healthcare practitioners that have received training to diagnose and treat all conditions that affect a person’s eyes and vision.

To qualify as an ophthalmologist in the United States, a person must complete approximately 12 years of education and training. This consists of 4 years each of college and medical school, alongside 4–5 years of additional training.

An ophthalmologist may choose to complete a fellowship to become a subspecialist in one area of eye health. This training prepares them to treat more specific or complex conditions in different parts of the eye or a particular group of people.

Subspecialists can specialize in:

  • The cornea: This focuses on cataract surgery, corneal transplantation, and refractive eye surgery.
  • The retina or uveitis: This area specializes in conditions that affect the retina and vitreous. This would include laser treatment and surgical treatment of conditions, including diabetic retinopathy and retinal detachment.
  • Glaucoma: This area focuses on medical and surgical treatment of conditions that cause damage to the optic nerve.
  • Pediatric ophthalmology: This subspecialty focuses on eye conditions that affect children.
  • Plastic and reconstructive surgery, or oculoplastics: This involves learning how to perform surgical procedures, including removing tumors and repairing bony fractures.
  • Neuro-ophthalmology: This area relates to the neurological conditions that include visual manifestations.
  • Ocular oncology: This involves the diagnosis and treatment of cancer in or around the eye.

Learn more about the anatomy of the eye here.

Common conditions that ophthalmologists treat include:

  • cataracts, which cause a cloudy patch on the lens of the eye
  • glaucoma, which damages the optic nerve, leading to a build-up of fluid
  • strabismus, or squint, which is when the eyes are not aligned
  • amblyopia, or lazy eye, which is when the eyesight does not develop properly in one eye
  • retinal problems, such as swelling, bleeding, and retinal detachment
  • intraocular inflammation, which is inflammation that occurs within the eye
  • corneal pathology, which are diseases that affect the cornea

They can also treat:

  • macular degeneration, which affects the retina, resulting in central vision loss
  • minor and major eye injuries
  • infectious eye disease
  • diabetic retinopathy
  • rare diseases of the eye, such as bloody tears, or hemolacria

Ophthalmologists can perform various tests that will depend on whether a person has a specific eye-related problem or requires a routine eye exam.

A comprehensive eye exam will take between 45–90 minutes.

The ophthalmologist will ask the person about their medical history, including that of family members.

They will then begin testing and examining the eyes. This could include:

Visual acuity test using an eye chart

The ophthalmologist will ask a person to stand 20 feet away from a chart, cover one eye, and say what they can see.

The most common eye chart is a Snellen chart, which displays letters that decrease in size from top to bottom. This helps the doctor understand how sharp a person’s vision is.

Visual field assessment

Visual field assessments involve an ophthalmologist measuring how much vision a person has in either eye, whether they have any blind spots or any other conditions that may affect a person’s sight.

Tests include:

  • confrontation visual field test
  • automated static perimetry test
  • kinetic visual field test
  • frequency doubling perimetry
  • electroretinography
  • Amsler grid

Eye pressure testing

Too much pressure can damage the optic nerve and sometimes lead to glaucoma.

An eye pressure test is called tonometry.

There are different types of tonometry, including:

  • Application tonometry: The ophthalmologist first numbs the eyes before touching the front of them with a handheld device that glows blue. This method is more accurate than other methods, such as non-contact tonometry.
  • Non-contact tonometry: This test uses a puff of air to determine the pressure. Although this method may be less accurate, it does not require the use of numbing drops.
  • Rebound tonometry: An ophthalmologist uses a small ball projected toward the cornea. It measures the resistance of its return to the machine.
  • Indentation tonometry: An ophthalmologist uses a tool called a tono-pen. This is a hand-held device that determines the force needed to indent the cornea.

Eye movement test, or ocular motility

This test shows whether a person’s eyes align and whether the eye muscles are working correctly.

Assessing the front of the eye, the retina, and optic nerve

The ophthalmologist will use a slit-lamp microscope to light up the front of the eye. They may also use a small lens to look into the back of the eye and inspect the retina, macula, and optic nerve.

This test checks for cataracts or signs of damage to the cornea.

They may also apply eye drops to dilate the pupil. This allows them to inspect the retina and optic nerve for signs of damage. The drops will also allow an ophthalmologist to see further into the back of the eye. However, they are still able to see this without dilating the pupils.

Finding the prescription for eyeglasses and contact lenses

To find the right prescription for eyeglasses or contact lenses, an ophthalmologist will ask a person to look through a phoropter, which is a device containing different lenses.

Other tests

If there is a need for further testing, an ophthalmologist might recommend the following tests:

  • optical coherence tomography, which is an imaging test
  • fundus photos, which are visual records focusing on the retina
  • topography, which is a scan of the surface of the cornea

An ophthalmologist may also perform a fluorescein angiography.

This is a medical procedure in which an ophthalmologist will inject dye into a vein in the arm or hand. The dye then travels through the veins and into the blood vessels within the eye. This allows the ophthalmologist to take pictures of the back of the eye.

Other eye care professionals include:

  • Optometrist: This eyecare professional primarily performs eye exams and vision tests, prescribes and fits glasses and contact lenses, and manages and treats specific eye abnormalities. They can prescribe some medicines.
  • Optician: An optician uses prescriptions that an ophthalmologist or optometrist provides to fit eyeglasses and contact lenses.
  • Ophthalmic medical assistant: These healthcare professionals help an ophthalmologist. They perform tests and help to treat people.
  • Ophthalmic technician: A technician assists the doctor with more complicated tests and minor surgery.
  • Ophthalmic registered nurse: A registered ophthalmic nurse works alongside an ophthalmologist on more technical tasks, such as injecting medications or assisting with hospital surgery.

The American Academy of Ophthalmology (AAO) recommends that adults with healthy vision have a complete eye exam by 40 years old.

Some people should get their eyes checked sooner. This includes people who have:

An optometrist or ophthalmologist can perform a routine eye exam and refer a person for further testing if necessary.

A family doctor can refer a person to an ophthalmologist. Additionally, optometrists may also refer people to an ophthalmologist. This may happen if a person needs surgery or injections for diabetic retinopathy or macula degeneration.

Alternatively, a person can ask for recommendations from family and friends.

A person can also find a local ophthalmologist using online directories.

The AAO has an online directory, which people can access here. A person can find a retina specialist using the American Society of Retina Specialists using this online tool. The National Health Service also provides a directory for those living in the United Kingdom.

A person should visit an ophthalmologist if they experience any of the following symptoms:

  • eye pain
  • decreased vision
  • new eye floaters, which appear similar to black “strings” or specks that float across a person’s vision
  • flashes of light
  • colored circles, or haloes, around lights
  • redness of the eye
  • eye discharge or tearing
  • bulging of one or both eyes
  • esotropia, or crossed eyes
  • diplopia, or double vision
  • seeing spots or ghost-like images
  • lines and edges appear distorted or wavy
  • dry eyes with itching and burning

A person should see an ophthalmologist if they have a family history of eye disease. Additionally, a person should visit an ophthalmologist if they have diabetes, as this can lead to diabetic retinopathy.

Insurance plans may cover services related to vision care. A person should check their health insurance to find out:

  • what eye care services their plan covers
  • what the out-of-pocket costs will be
  • which eye doctors their plan’s network includes

Medicare may cover some services related to eye and vision care.

Learn more about Medicare and vision care here.

Lower cost options

There is a range of programs that may help cover the cost of eye care for people who do not have insurance, for example. These include:

  • EyeCare America provides eye exams for those with lower incomes.
  • SightFirst can help people to receive vision support.
  • Infant SEE is a health program that provides comprehensive eye and vision assessments at no cost for those ages 6–12 months old, regardless of the family’s insurance coverage or income.

People can also contact their state’s Medicaid department to find out what assistance is available to them.

An ophthalmologist is a highly qualified healthcare professional trained to perform routine eye exams and diagnose and treat all conditions that affect the eye.

People with a family history of eye disease, diabetes, or vision changes should consider visiting an ophthalmologist.