What Is an Optometrist?

An optometrist is an eye doctor who diagnoses and treats eye diseases and disorders. Optometrists are the eye doctors in charge of your primary eye health care. This includes conducting eye exams, prescribing glasses or contact lenses, and prescribing medications.

However, your eyes don’t exist in isolation from the rest of your body. Optometrists also help to diagnose systemic diseases such as diabetes and high blood pressure.

In fact, doctors of optometry can help detect more than 270 serious health conditions, including high blood pressure and certain types of cancers, according to the American Optometric Association. Regular visits to an optometrist can help maintain your overall health.

An optometrist is not a medical doctor (MD). Optometrists earn the designation OD, which is short for optometry doctor. This means that after four years of college, they attended four years optometry
school.

Concentrations

The eyes provide a window to the rest of your body, and that’s how optometrists can use their exam findings to help detect other health problems, such as diabetes. Sometimes, signs of certain diseases are visible in the eyes before or in addition to the other parts of the body.

For instance, changes to blood vessels in the back of the eye could reveal poorly controlled diabetes. If you don't already know that you have diabetes, an optometrist will advise you to follow up with your primary care doctor for a glucose test.

The following are among the conditions that an optometrist can diagnose and treat:

• Amblyopia: Vision loss with no detectable cause; also called “lazy eye”
• Astigmatism: Blurry vision due to an irregular cornea
• Blepharitis: Inflammation of the eyelid
• Cataracts: A clouding of the lens
• Chalazion: A bump on the edge of the eye
• Diabetic retinopathy: Damage to the retina of the eye caused by diabetes
• Dry eye disease: Inflammation of the eye’s cornea or conjunctiva
• Eye duct obstruction
• Eye emergencies and injuries
• Eye infection
• Glaucoma: A disease usually caused by high eye pressure
• Keratoconus: A condition that changes the shape of the cornea and affects vision
• Macular degeneration: An age-related loss of vision
• Ocular allergies
• Pink eye: Also known as conjunctivitis
• Refractive errors: Hyperopia (farsightedness) and myopia (nearsightedness)
• Strabismus: Misalignment of the eyes
• Styes: Bacterial infection of an oil gland in the eyelid

Procedural Expertise

Optometrists use a series of tests to check your eyes. A comprehensive eye exam is the most common way that optometrists will monitor your eye health and detect problems or vision loss.

Comprehensive Eye Exam

There are a few ways that optometrists assess your eyes during a comprehensive eye exam:

• Health history: Optometrists will initially ask you about any vision problems you’re having and your overall health. Make sure to let them know if you have any systemic health problems, such as high blood pressure or heart disease. This is also the time to let the optometrist know what medications you use, even if they are not for your eye health.
• A visual acuity test: Have you seen those charts that doctors sometimes have on the wall with the big letter “E” at the top and several small letters below? That’s one tool that an optometrist might use to measure your vision. The optometrist will likely use a phoropter to measure your vision during this part of the exam. A phoropter is an ophthalmic testing device with various lenses.
• Color blindness test: This can detect if you have any color blindness
• Depth perception test: Also called a stereopsis test, testing for depth perception ensures that you can see objects three-dimensionally.
• Keratometry and topography: The cornea is the clear outer surface of your eye. The optometrist will use keratometry and topography to measure the curvature of your cornea. The results of this test are especially important if you are getting fitted for contact lenses.
• Ocular motility testing: This type of testing ensures that your eye movements can easily follow a moving object.
• Peripheral visual field test: An optometrist has several types of tests to make sure you can see not just what’s in front of you but also on the side. This is called your peripheral vision.
• Refraction: The phoropter is used to determine if you have a refractive error such as myopia, hyperopia, or astigmatism. The optometrist will show you series of letters and ask which one is clearer. An autorefractor is used to measure your prescription for eyeglasses and contact lenses. You look at a picture in the autorefractor. It goes in and out of focus as the autorefractor takes a reading to determine your refraction.
• Retinoscopy: A retinoscopy test helps the optometrist to determine the need for glasses.
• Slit lamp exam: An optometrist uses a special type of microscope with a light called a slit lamp to examine parts of your eye, such as cornea, iris (the colored part of your eye), and the lens. It’s also possible to look at the back of your eye, such as the retina, using the slit lamp. Slit lamp exams help detect cataracts, dry eye, injury to the cornea, or macular degeneration.
• Tonometry: Optometrists use a tonometer to help detect glaucoma. This is done by measuring the pressure in your eye. The tonometer measures the rate at which a fluid called aqueous humor drains into the tissue around the cornea, which in turn causes eye pressure.

Specialized Exams

In addition to the comprehensive eye exam tests above, an optometrist may choose to perform other specialized exams to assess your eye health. These include the following:

• Aberrometry: With the use of a machine called an aberrometer, an optometrist can use what is called wavefront technology to further pinpoint visual errors. This type of technology is more common using during pre-surgical exams for LASIK eye surgery.
• Applanation tonometry: This variant of traditional tonometry involves the use of an applanation tonometer, which is a device your optometrist can attach to the slit lamp. After inserting yellow drops into your eyes (these are not the same as dilating drops), the optometrist can use applanation tonometry to measure your eye pressure and help detect glaucoma.
• Pupil dilation: By dilating your eyes, an optometrist can get a better look at the eye and check for certain eye diseases. Eye diseases such as glaucoma may not have any symptoms until they are advanced. That’s why dilation is important. The eye drops temporarily make your pupils bigger and make your eyes more sensitive to light. You usually don’t need to dilate your eyes at every routine eye exam. Ask your eye doctor how often you should get your pupils dilated. If you are over age 60 or have a family history of glaucoma, you may need to get your eyes dilated more often.

Treatments

While glasses and contact lenses are the two most obvious treatments provided by optometrists, there actually are many more treatments they can provide, depending on your eye problem. These include:

• Prescribing medications that help the eyes: The medicated eye drops could be for glaucoma or dry eye, for example.
• Removing foreign bodies from the eye: Just about any object can enter the eye due to an accident or injury. Optometrists can help to carefully remove this foreign body.
• Soothing dry eyes: About 5 million Americans have a condition called dry eye. Optometrists can diagnose dry eye and recommend treatments. Although artificial tears and medications are used for dry eye, your optometrist may advise you to do certain things to make your eyes more comfortable. This could include using a humidifier and taking breaks from staring at a screen all day.
• Providing vision therapy to help improve your visual function: Vision therapy is usually done with special lenses, prisms, and computer programs.
• Caring for your eyes after you have eye surgery: An optometrist may be the doctor who will see you regularly after eye surgery to make sure you are recovering as expected.

Subspecialties

Optometrists can assist with a wide range of eye problems, but some optometrists will further specialize in a certain area so they have a deeper knowledge. The following are subspecialties within
optometry.

Cornea and Contact Lenses

Optometrists with a specialty in cornea and contact lenses have more in-depth knowledge about diagnosing and treating various diseases of the cornea and conducting contact lens fittings. This can include the use of specialized contact lenses.

Ocular Disease

Optometrists who have subspecialized in ocular disease are trained to detect a variety of diseases that affect the front and the back of the eye, including glaucoma and macular degeneration.

Low Vision

Optometrists treating low vision help patients with a visual impairment that cannot be helped through surgery, glasses, or contact lenses. Low vision is more common among older adults. There are tools and technology to help those with low vision.

Pediatrics

Vision problems can affect a child’s development. Optometrists specializing in pediatrics treat children and their vision disorders. In addition to performing routine eye exams, pediatric optometrists diagnose and treat binocular vision and help to provide vision therapy.

Geriatrics

Geriatric optometrists are specially trained to provide eye care to older adults. They frequently diagnose and treat eye problems more common in older adults, including diabetic retinopathy and macular degeneration.

Neuro-Optometry

Neuro-optometrists diagnose and treat vision problems related to the brain. This could include vision loss associated with neurological diseases, trauma, or congenital (present at birth) conditions.

Behavioral Optometry/Vision Therapy

Behavioral optometrists focus on how visual function affects your daily activities. Behavioral optometrists may aim to improve visual function through vision therapy, including eye exercises and the use of special prisms and lenses.

Training and Certification

After earning a bachelor’s degree, optometrists attend optometrist school for four years. Their schooling combines classroom learning with clinical experience. Some optometrists will go on to complete a one-year residency in a specialty area, such as low vision, pediatric optometry, or ocular disease.

All optometrists must be licensed in their state and complete the National Board of Examiners in Optometry exam. All states require optometrists to renew their license periodically and take continuing education classes. Some states may have additional requirements for optometrists.

Optometrists also can become board certified by the American Board of Optometry to show advanced knowledge within their field.

Appointment Tips

Ask your primary care doctor for optometrist recommendations if you do not currently have one. The American Optometric Association also has a site to help you find an optometrist. You can use this site to find an optometrist by location, languages spoken, and specialties.

Here are a few ways to help prepare for your visit to an optometrist:

• Bring your current eyeglasses and contact lenses with you.
• Bring your vision insurance information with you if you have it. To receive insurance coverage from an optometrist visit, you usually need vision insurance that is separate from your regular health insurance.
• Be ready to provide the names of any medications you currently use. You may want to write out a list of your medications in advance, including medications that are not used for the eyes.
• Find out in advance if the optometrist plans to dilate your eyes. Dilation affects your vision, so you will need someone to drive you home. If you are getting your eyes dilated, bring sunglasses as the dilation will make your eyes more sensitive to light. If you don’t have sunglasses, the office should be able to provide a disposable pair.
• Note in advance any questions you may have for the optometrist. It's often helpful to bring a list along so you don't forget the ones you wanted to ask.
• If you receive a new prescription for glasses or contact lenses, ask for a copy of the prescription.
• If your optometrist prescribes any eye drops, ask how you should use them. Many times, people don’t administer eye drops correctly. That means the medicine doesn’t reach the eyes or work as effectively as it should.

A Word From Verywell

Optometrists can do a lot to help preserve your vision and even help monitor for common systemic diseases. Regular visits to an optometrist help ensure that you can see clearly and that you keep your vision crisp now and in the future.