Eye Exam: What to Expect
What is an eye exam?
During a complete eye exam, your provider takes a close look at your eyes and does several tests. Some tests check your vision and determine if you need glasses or contacts. Other tests assess your eye health and check for eye disease. An exam can help providers evaluate your overall health.
Your provider will use special equipment, instruments and lights to look in your eyes. These tests don’t usually hurt, but they may be a little uncomfortable. With regular eye exams, your provider monitors changes in your vision, detects eye problems and helps you keep your eyes healthy.
What’s the difference between an ophthalmologist, optometrist and optician?
Optometrists and ophthalmologists are doctors who specialize in caring for your eyes. An eye doctor performs eye exams and diagnoses and treats eye problems. Ophthalmologists can also perform surgery to correct eye issues.
An optician helps you with corrective lenses. An optician isn’t a doctor, but they have training to help you choose eyeglass frames. They also ensure that glasses and contact lenses fit.
How often should I get my eyes checked?
Most children and adults should get a comprehensive eye exam every one to two years. People with a higher risk of eye disease or vision problems may need to get their eyes checked more often. You may need more frequent eye exams if you:
- Are over age 60.
- Are of African or Hispanic descent.
- Carry extra weight or have obesity.
- Had eye surgery, an eye injury or eye damage from a stroke.
- Have a family history of eye disease.
- Have a health condition that can cause eye problems, such as diabetes.
- Wear glasses or contact lenses.
What tests should I expect during an eye exam?
After asking about your health and family history, your provider will perform several tests. Some tests check your vision. Other tests evaluate your eye health, including the muscles and blood vessels around your eyes.
During an eye exam, your provider will shine a light on your pupil to see how it dilates. The pupil is the small opening at the center of your iris (the colored part of your eye). Your provider will also check how your eyes move, focus and work together as a team. Standard tests during an eye exam include:
- Visual acuity: Your provider asks you to read letters on an eye chart (a Snellen chart) from a distance. You’ll cover one eye at a time. Your provider may ask you to read the letters when looking through a device called a phoropter, which has several lenses to help you see better. This process, called refraction, tells your provider if you need glasses and helps find the right corrective lens prescription.
- Automatic refraction: Providers use an autorefractor to measure visual acuity in young children and people who have trouble communicating. An autorefractor shines light into the eye and measures the eye’s response. Automatic refraction lets providers find the right lens prescription to correct vision.
- Visual field: To check your peripheral (side) vision, your provider holds up a finger or an object and gradually moves it from one side of your face to another. Your provider may move the object up and down and bring it closer to your eyes. You’ll only move your eyes, not your head. Many doctor's offices use a computer program to conduct this test. This test tells providers about your full range of vision.
- Color vision test: To check for color blindness (color deficiency), your provider will show you a series of images with colored dots. Hidden among the dots are numbers in different colors. People with a color deficiency may not be able to see the numbers.
- Corneal topography: Your provider uses a computer to create a “map” of your cornea. You look at an object, and the computer takes thousands of measurements of your cornea. This test can show a curvature of the cornea (astigmatism). Providers use it to fit contact lenses and prepare for corneal transplants and other eye surgery.
- Ophthalmoscopy: Your provider uses eyedrops to make your pupils dilate (get bigger). You’ll wait while your pupils fully dilate (about 15 to 20 minutes). Then your provider uses a handheld instrument to shine a light in your eye. With your pupils open, your provider can examine the cornea, lens, retina, optic nerve and surrounding blood vessels. Another name for this test is fundoscopy.
- Slit-lamp exam: After dilating your pupils with special eyedrops, your provider examines your eyes using a microscope (slit lamp) mounted to a table. You rest your chin and forehead on the equipment. Your provider looks at your eyes through the slit lamp. The slit lamp allows your provider to see the parts of your eye under high magnification.
- Tonometry: This test detects problems with pressure in the eye. Increased pressure is a sign of glaucoma. Your provider places drops in your eyes to numb the area. Then an instrument called a tonometer blows a small puff of air on the cornea. During applanation tonometry, your provider uses a flat-tipped cone that gently comes into contact with your cornea. The device measures the amount of pressure needed to flatten a portion of your cornea.
- Fundus photography and optical coherence tomography (OCT): These imaging tests are used to evaluate structures in the eye such as the retina and optic nerve. The pupil is usually (but not always) dilated first. A camera is used to obtain digital images (photos), or a computerized low-power imaging scanning system is used to obtain thousands of images in a few seconds (OCT). Image patterns can be used to diagnose and/or follow various retinal, optic nerve, and corneal conditions.
What do eye exams evaluate?
Comprehensive eye exams give your provider information about your vision. They tell eye doctors whether you need corrective lenses and what your prescription is. During an eye exam, your provider will also look for eye-related concerns, including:
- Refractive errors, such as astigmatism, myopia (nearsightedness), hyperopia (farsightedness) or presbyopia (losing near-focus vision).
- Changes in vision, low vision, and signs of cataracts, glaucoma, macular degeneration or a detached retina.
- Problems with the muscles supporting the eyes, such as strabismus (crossed eyes) or amblyopia (lazy eye).
- Tumors and cancer in the eye (intraocular cancer), including intraocular melanoma and retinoblastoma.
Your provider will also check for a wide range of conditions, diseases and disorders that aren’t necessarily eye-related. Problems or changes in the eyes can be a sign of several conditions, including:
- Autoimmune disorders, such as lupus and multiple sclerosis (MS).
- Diabetes, which can cause diabetes-related retinopathy.
- High blood pressure, high cholesterol or arterial disease.
What should I expect after an eye examination?
If you’ve had your eyes dilated, your vision will be blurry for several hours after the exam. Your eyes will also be more sensitive to light. For a few hours after an eye dilation, you should avoid driving, reading and looking at screens. Make sure to wear sunglasses to protect your eyes from the sun as your pupils shrink back to normal. If you don’t need dilation, you can get back to your usual activities right away.
Results and Follow-Up
When should I know the results of the eye exam?
Most of the time, your provider will give you results from your eye exam right away. If you need glasses or contacts, you’ll leave the appointment with a prescription. You’ll also have information about your vision, eye structure and eye health. Sometimes your provider may recommend a follow-up appointment or additional tests.
A note from Cleveland Clinic
Eye exams not only help you see better, they also detect eye problems that can cause vision loss. Many of these problems don’t have any outward signs or symptoms, so the only way to catch them is through an exam. Ask your provider how often you should get an eye exam. When you see your eye doctor, be sure to share information about your family’s eye health history. Regular eye exams are an essential part of maintaining good overall health.
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