What to expect in an eye exam
Everyone remembers seeing the big “E” at the eye doctor’s office. But if it has been a few years since visiting the doctor’s office, there might be some questions about the process. Let’s talk about what to expect at your eye exam.
What is an eye exam?
Eye exams are an important part of routine body maintenance. These painless procedures help with early detection of eye disease, result in clearer vision and, sometimes, result in new contact lenses. They also offer you a chance to talk with your doctor face to face about eye health issues.
Eye exams are not just for people who want to wear glasses. Eye exams allow doctors to make recommendations for contact lenses as well. Eye care professionals provide reliable information about eye care and can offer basic demonstrations on how to wear and care for your contact lenses.
So, what is ExpressExam?
Our online vision test is not a comprehensive eye health exam like you’d get with your eye doctor’s office. It serves another purpose, which is to renew your contact lens prescription. We always recommend going in for a full eye exam if you have any concerns about your eye health or if you feel you need an updated prescription.
It’s the perfect fit for someone who loves their brand, but just needs a renewed prescription for some new contacts. It’s not meant to replace a traditional eye exam but works perfectly when you’re in a pinch.
What tests should I expect at an eye exam?
Eye doctors usually perform a series of routine tests as part of the eye health exam. Here’s a brief explanation for each one.
Visual acuity testing
These common tests occur at most eye exams. Most people know the “Snellen” Chart as the one with the big “E” on top. This tool determines how well someone is able to see, also referred to as their visual acuity. This tests their ability to read letters without squinting from a distance of 20 feet. Those with normal vision have an acuity of 20/20.
Color blindness testing
This test determines your ability to see subtle color differences and helps to detect color blindness. This test can also detect eye health problems that may affect color vision.
Depth perception testing
This test measures your stereopsis, or depth perception. The process usually involves viewing images made up of dots or pictures, sometimes through special glasses. This determines how well someone can see in three dimensions. It also helps to detect eye diseases such as amblyopia, strabismus, suppression, and stereopsis.
Muscle testing
This test is done to let your doctor determine how well your eyes work together and if there’s any muscle imbalance that may cause one or both eyes to want to not point straight. Muscle testing also helps ensure that all your eye muscles and nerves work well together. Eye muscle tests require very few tools. The doctor asks you to follow an object across six different positions, exposing weakness in muscles.
Pupil testing
Pupil testing is usually done with a small bright flash light. The eye care professional shines a penlight over one eye at a time and looks for pupil dilation and contraction.
Autorefraction
This test uses a computerized instrument to measure how light focuses through your eye and gives the doctor a preliminary measure of your prescription.
Retinoscopy
This test also helps the doctor determine your prescription by measuring what lenses it takes to focus light perfectly on the back of your eye.
Eye pressure testing (tonometry)
The pressure inside your eye is very important to measure, because high pressures can be one risk factor for glaucoma, a potentially blinding eye condition. The eye pressure is measured one of several different ways. Doctors will sometimes use a computerized instrument that blows a gentle puff of air in the eye.
Pressure can also be measured with various other handheld devices that gently touch the surface of the eye. The doctor may also use an instrument that is attached to the microscope and uses dye in the eye and a blue light.
Refraction
The refraction test determines the ideal prescription for you. During this test, you are given something to look at (usually the Snellen chart or something similar) and asked to determine your best vision from a series of options. You look through the phoroptor, deciding between two lenses at a time. This is the part of the exam when you can expect to hear “one or two” and “three or four” over and over again. The eye care professional uses your choices to determine which, if any, prescription you need.
Slit lamp examination
Your doctor will use a high-powered microscope called a slit lamp to thoroughly examine the structures on the outside of the eye under magnification. The doctor will also use a strong lens to focus on the structures inside of the eye. During this test, you’ll comfortably place your chin on the chin rest of the slit lamp while the doctor shines a bright light toward the eye.
Visual field testing
These tests measure your peripheral vision. Peripheral tests are given by having you look in a fixed forward direction, then introducing images from behind and to the sides of your eyes. This measures how well you can see at the edges of your vision as you focus on a point directly ahead.
Visual field testing may also be done with an automated instrument that presents lights or other targets and asks you to click a button when you see them like a video game. Peripheral tests can help discover glaucoma damage as well as neurological problems.
Pupil dilation
Your doctor will likely need to put drops in your eyes that enlarge the size of the pupil in order to get a wider view into the inside of the eye. It takes about 20 minutes for the drops to work, then the doctor will examine the structures inside the eye with a special headset mounted microscope and with the slit lamp. Pupil dilation will make it a little harder to focus at near distance and will make you more sensitive to bright light, but is a very important test to provide a thorough examination of eye health.
Other testing
Depending on the examination findings, your doctor may order further testing such as photographs of the inside of your eyes, scanning images of the layers of the retina, or other diagnostic testing as needed.
Contact lens fitting and evaluation
Contact lenses come in many different shapes, sizes and materials. Which means finding the perfect lens fit is essential for maximum comfort. This will usually involve placing the lens on the eye and evaluating the way the lens sits on the eye surface and moves with a blink.
Contact lens evaluations are important even if you have worn contacts for many years to be sure that the lenses are still providing for optimal eye health. Once these measurements are found, the other parameters of the contact lens (such as the power) are determined by the refraction test.
Original published date: 1/23/2020
Updated: 11/28/2022