The first step toward good vision health is your eye exam—and it involves much more than correcting your vision with glasses or contacts. If this is your first appointment with your eye doctor, then you’re in luck. In a short time, you’re going to learn more about your vision and eye health then you probably ever have, and your doctor will learn more about your general health condition. Oh, and you may wind up with a very cool pair of glasses as well!
An eye exam can actually be a lifesaver in that serious and pervasive eye diseases may be detected and treated early on. In fact, a comprehensive eye exam is less about your eyeglass prescription and more about your overall health.
Here are some of the components of a typical eye exam and some tips to make the experience more pleasant (please note: your eye doctor may choose to follow a somewhat different regimen than outlined).
Don’t Be Nervous!
A comprehensive eye exam doesn’t hurt, but it does involve a series of important tests to evaluate your vision and check for eye diseases. Your eye doctor has some highly technical equipment to allow him or her to see into your eye, check your peripheral vision as well as intraocular pressure. And there’s an extensive collection of lenses for you to look through to measure for vision correction. Each test evaluates a different aspect of your vision and eye health.
The whole process usually starts with your doctor or a technician taking a detailed medical history. Then, your eye doctor makes a quick check of your eyes using a light to make sure the exterior parts are functioning correctly. Lastly, your doctor measures your visual acuity, assesses your need for glasses and examines your eyes for signs of disease.
Following your initial exam, here are several of the tests that may be performed:
- VISUAL ACUITY TEST This is the “eye chart” test that most people are familiar with. You’re positioned 20 feet away, and the eye doctor will ask you to identify different alphabet letters printed on a chart (commonly called a Snellen Chart). The lines of type get smaller as you move down the chart. You cover one eye and read aloud, then cover the other eye and read aloud.
- VISUAL REFRACTION Refraction refers to how light waves are bent as they pass through your cornea and lens. A refraction assessment helps your doctor determine a corrective lens prescription that will give you the sharpest, clearest vision.
Your doctor will very likely begin by using a device called a phoropter, which allows her or him to subjectively determine your refractive error. This exam is performed in a dark room to enable you to better see the images through the phoropter lenses. By repeating this step several times, your doctor finds the lenses that give you the greatest possible vision. Afterward, the doctor may use a computerized refractor to measure your eyes and reaffirm the prescription determined during the subjective refraction.
- VISUAL FIELD TEST This is used to determine the visual width of the area right in front of you, in which you can see without moving your eyes, and also checks your peripheral vision. While there are a few different types of visual field tests, the most common procedure is performed with a device called an autoperimeter. Simply, your doctor uses a computer program that flashes small lights as you look into the bowl-shaped autoperimeter. You press a button when you see the lights.
- SLIT-LAMP EXAMINATION A slit lamp is a microscope that enables your doctor to use intense light to enhance the view of your eye, in order to examine the cornea, iris, lens and anterior chamber. When examining your cornea, your doctor may use eye drops containing fluorescein (flooh- RES-ene) dye. This orange dye allows your eye doctor to look for small cuts, scrapes, tears, foreign objects, or infections on your cornea. As you blink, your natural tears will rinse it away.
- GLAUCOMA TEST This exam measures the pressure inside your eye, referred to as intraocular pressure. It helps your eye doctor detect glaucoma, a disease that causes pressure to build up inside your eyes and can cause blindness. Glaucoma can be treated if it’s caught early. The most common test for eye pressure today is called non-contact tonometry. The device called a tonomoter ejects a puff of air into your eye to test the pressure.
Another commonly used glaucoma detection method is called pachymetry, which measures the thickness of your cornea, an important factor in evaluating your intraocular pressure measurement. Those are just some of the basics of your eye exam. DON’T be afraid to ask questions and DO be sure to make a return appointment per your doctor’s recommendation.
Your eye doctor is among a group of vision care professionals who pride themselves on offering excellent care. Be sure to let him or her know whatever questions you may have.