You're scared of the dreaded “air-puff.” Go on. Admit it. You've heard your doctor shines paralyzing bright lights in your eyes and you're light sensitive so not sure how you'll hand it! There's no need to prepare for an eye test.
In this blog update, we'll break down the equipment and basic testing your likely to encounter at your eye examination. Keep in mind that although there are many tests that we will complete at every examination, every eye exam is a little different because your doctor is addressing your individual needs. There is not a “one-size-fits-all” eye examination but continue reading to learn about the basics.
1. Pre-Testing/Entrance Testing
Before you see your doctor, one of our assistants will gather information about your eyes for the doctor to review. Your first stop will be our pre-test room. In this room, you'll find a tonometer, keratometer, and retinal photography. A lot of big words for very important information.
A tonometer measures the pressure in your eye. The non-contact tonometer or the “air-puff” test is the easiest way to measure this quickly and non-invasively. The machine lets a small puff of air out and measures the way your cornea (the clear front of your eye) responds to the air puff to measure the pressure in your eye. The air-puff is painless and the instrument never touches your eye. We have three different ways to measure the pressure in your eye in office. The other methods will be completed by your doctor if needed for individual reasons and require the instillation of drops, as well as brief contact with your eye. Your doctor will assess if the pressure in your eye is normal or if there is concern for disorders such as glaucoma due to elevated pressure or different causes of inflammation in your eye if there is a large difference between your eyes.
The next test you'll complete is auto-refraction/auto-keratometry. During this test, you'll simply look into a machine that will take several measures of your eye as you focus on a picture. There is no bright light, no puff of air, and nothing to touch your eye. This instrument completes auto-refraction and aberrometry or in other words, gives your doctor a rough estimate of your prescription and the state of your cornea and lens. It also completes auto-keratometry which measures the shape of your cornea. This is especially important if you are a contact lens wearer or wanting to try contacts.
One last test before leaving this room is retinal photography. This test gives your doctor an image of the back of your eye and provides them with valuable information about your health.You can learn more about the Optomap Ultra-widefield Imaging by clicking here.
2. Objective Testing
What's next? The assistant will then take you into the examination room. Here is where you read the eye chart. No studying required. We use digital charts so no memorizing and much more variety. Want to learn more about the science behind the eye chart such as why we use the letters we do and how the size of the letters is determined? Click here.
This is where we will also get a brief history of your health, eye wear, medications, etc and, yes, we do need to know what medications you are taking. Your eyes are part of your body. They share a blood supply and so your general health and medications do affect your vision, prescription, and eye health.
Thought you were done and ready to get a prescription? Not quite. At this point, either the assistant or doctor will gather still more information about:
1. Your Visual Field: There are machines that we can use to test your peripheral and central vision exactly but we like to screen everybody and save those specific tests for only when needed. To do this, we complete confrontation visual field testing on every patient. You will be asked to look at a target (usually your examiner's eye) and count fingers that are held in your side vision.
2. Eye Muscle Testing: Follow the light! Your doctor will check your eyes abilities to move into different directions of gaze both individually and together. Changes in your eye muscles abilities can tell us a lot about your binocular vision but also the function of your nervous system and even your blood flow sometimes!
3. Your Binocular Vision: We could write an entire blog on only this section but here's the nitty gritty. Your doctor will screen you for crossed eyes or strabismus and the ability for your eyes to work together using a cover/uncover test and a stereoacuity test. In a cover/uncover test, you will look at a target while your doctor covers and uncovers your eyes and observes their movement. A stereoacuity test has you observe and answer questions about some images to measure your ability to see “3D.” All other binocular vision tests will be completed on a case-by-case basis determined by your personal history, the results of the screening, and your needs.
3. Refractive Testing
Ahhhh...Finally, the reason you came here, right? Your doctor will use a phoropter or the “big pair of glasses” to determine your glasses prescription. The phoropter is made up of many different lenses to test for near-sightedness, far-sightedness, astigmatism, and presbyopia. It can even be used to balance your eye muscles to prevent double vision. Your doctor will have you answer several questions including the infamous "1 or 2" to use the phoropter to determine your prescription. Want to learn more about this process? Click here.
4. Ocular Health Examination: The Slit Lamp Examination, Dilation, and Internal Ocular Health.
You came for the glasses or contact prescription but this is why your doctor wants you to get your eyes checked. As doctors, we want your whole self to be healthy and your eyes are our windows into your health picture. Your doctor will use a slit-lamp which is essentially a specialized microscope to evaluate the front of your eye including your eyelids, lashes, the white part of your eye, the cornea, and iris (color part of your eye) and the lens to look for disorders such as cataracts. They will then use a series of lenses to shine light through the pupil (the hole in the colored part of your eye) to see INSIDE your eye. Some people may need to be dilated to have this completed but don't worry, you can still drive dilated and we will provide you with sunglasses to make you comfortable. They're super stylish, wink, wink. If your prescription is such that we do not deem it safe for you to drive, then we can complete this on a different day. Many people do not require dilation for this test at every visit though especially if you have agreed to the Optomap Ultra-Widefield Retinal Imaging. Your doctor will review all findings with you.
Want contacts? That is an additional evaluation beyond your basic eye examination. Click here to learn about our contact lens exams.
Still have questions? We are happy to answer any questions via email or phone call at 573-756-5665! You can also read about what to expect on All About Vision's website at: What to Expect at Your Comprehensive Eye Exam