Eyecare experts recommend you have a complete eye examination every one to three years, depending on your age, risk factors, and physical condition. There are two kinds of eye doctors - ophthalmologists and optometrists. Ophthalmologists are medical doctors (MDs or DOs) who specialize in eyecare. In addition to prescribing eyeglasses and contacts, ophthalmologists are licensed to perform eye surgery and treat medical conditions of the eye. Optometrists (ODs) are eye doctors who can prescribe glasses and contacts and treat medical conditions of the eye with eye drops and other medicines.
What information should I take with me to my eye exam?
- All eyeglasses and contact lenses you routinely use, including reading glasses.
- A list of any medications you take (including dosages).
- A list of any nutritional supplements you take (including dosages).
- A list of questions to ask the doctor, especially if you are interested in contact lenses or laser vision correction surgery.
- Your medical or vision insurance card if you will be using it for a portion of your fees.
What can I expect from my eye exam?
Near Point Testing for Presbyopia
Presbyopia is a condition in which the patient's ability to focus on close objects or to see small print clearly diminishes over time. Additional tests are needed when patients have trouble
Visual Acuity Cover Test
This test checks to see how well you can recognize letters or objects on a chart. Each eye is done separately. The smaller the letter, the better your visual acuity. During a cover test, the eye doctor will have you focus on a small object at distance and will then cover each of your eyes alternately while you stare at the target. As they do this, eye doctors observe how much each eye has to move when uncovered to pick up the fixation target. The test is then repeated as you focus on a near object. Cover tests can detect even very subtle misalignments that can interfere with your eyes working together properly (binocular vision) and cause amblyopia or "lazy eye."
The slit lamp is an instrument that the eye doctor uses to examine the health of your eyes. Also called a biomicroscope, the slit lamp gives your doctor a highly magnified view of the structures of the eye, including the lens behind the pupil, in order to thoroughly evaluate them for signs of infection or disease. The slit lamp is basically an illuminated binocular microscope that's mounted on a table and includes a chin rest and head band to position the patient's head properly. With the help of hand-held lenses, your doctor can also use the slit lamp to examine the retina (the light-sensitive inner lining of the back of the eye.)
Autorefractors and Aberrometers
Your eye doctor also may use an autorefractor or aberrometer to help determine your glasses prescription. With both devices, a chin rest stabilizes your head while you typically look at a pinpoint of light or other image. An autorefractor evaluates the way an image is focused on the retina, where vision processing takes place, without the need for you to say anything. This makes autorefractors especially useful when examining young children or people who may have difficulty with a regular ("subjective") refraction. Automated refractions and subjective refractions are often used together during a comprehensive exam to determine your eyeglasses prescription. An aberrometer uses advanced wavefront technology to detect even obscure vision errors based on the way light travels through your eye.
This procedure illuminates and magnifies the interior of the eye, allows our eye doctor to look at the health of the blood vessels and the optic nerve. Many conditions such as diabetes, hypertension or glaucoma can be detected by looking inside the eye.
Tonometry (Glaucoma Testing)
Tonometry is the name for a variety of tests that can be performed to determine the pressure inside the eye. Elevated internal eye pressure can cause glaucoma, which is vision loss due to damage to the sensitive optic nerve in the back of the eye. The most common method used for tonometry is the "air puff" test - where an automated instrument discharges a small burst of air to the surface of your eye. Based on your eye's resistance to the puff of air, the machine calculates the pressure inside your eye - called your intraocular pressure (IOP). Another popular way to measure eye pressure is with an instrument called an applanation tonometer, which is usually attached to a slit lamp. For this test, a yellow eye drop is placed on your eyes. Your eyes will feel slightly heavy when the drops start working. This is not a dilating drop - it is simply a numbing agent combined with a yellow dye. Then the doctor will have you stare straight ahead in the slit lamp while he or she gently rests the bright-blue glowing probe of the tonometer on the front of each eye and manually measures the intraocular pressure. Since glaucoma is often the result of an increase of pressure inside the eye, these are important tests for ensuring the long-term health of your eyes.
This is the test your doctor uses to determine your exact eyeglasses prescription. During a refraction, the doctor puts the phoropter in front of your eyes and shows you a series of lens choices. He or she will then ask you which of the two lenses in each choice ("1 or 2," "A or B," for example) make the letters on the wall chart look clearer. Based on your answers, your doctor will determine the amount of nearsightedness, farsightedness and/or astigmatism you have, and the eyeglass lenses required to correct these vision problems (which are called refractive errors).
Your comprehensive exam may include the use of dilating drops. These medicated eye drops enlargen your pupil so your doctor can get a better view of the internal structures in the back of the eye. Dilating drops usually take about 20 minutes to start working. This enables the doctor to get a better view of the anatomy inside the eye. Without the dilation the doctor can only see about 50% of the eye. When your pupils are dilated, you will be sensitive to light, because more light is getting into your eye. You may also notice difficulty reading or focusing on close objects. These effects can last for up to several hours, depending on the strength of the drops used. If you don't have sunglasses to wear after the exam, disposable sunglasses will be provided to help you drive home. Dilation is very important for people with risk factors for eye disease, because it allows for a more thorough evaluation of the health of the inside of your eyes.
Automated Visual Field Test
This is an optional test provided at all of our locations. It is designed to help detect early changes in the peripheral vision, which can be indicative of sight threatening conditions such as glaucoma, brain tumors and aneurysms.
What's the difference between a vision screening and a complete eye exam?
Vision screenings are general eye tests that are meant to help identify people who are at risk for vision problems. Screenings include brief vision tests performed by a school nurse, pediatrician or volunteers. The eye test you take when you get your driver's license renewed is another example of a vision screening.
A vision screening can indicate that you need to get an eye exam, but it does not serve as a substitute for a comprehensive eye exam.
A comprehensive eye examination is performed by an eye doctor and will involve careful testing of all aspects of your vision. Based upon the results of your exam, your doctor will then recommend a treatment plan for your individual needs. Remember, only an eye doctor can provide a comprehensive eye exam. Most family physicians and pediatricians are not fully trained to do this, and studies have shown that they can miss important vision problems that require treatment.
Treatment plans can include eyeglasses or contact lenses, eye exercises or surgery for muscle problems, medical treatment for eye disease or simply a recommendation that you have your eyes examined again in a specified period of time.
No matter who you are, regular eye exams are important for seeing more clearly, learning more easily and preserving your vision for life.
For more information on eye exams, visit All About Vision®.
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