How Eye Doctors Test Your Vision
After an eye exam, we could be told we have 20/20 vision. Or that we are near-sighted, or far-sighted. Or have astigmatism. But how do eye doctors come to these conclusions?
A series of questions and tests are carried out to get an accurate evaluation of your ocular health. These results provide the next steps for correcting your vision and building a plan to keep your eyes happy!
How to Prepare for an Eye Exam
As a patient, you have two responsibilities going into an eye exam. First, understand the expectations in completing a visual assessment. Be honest with your doctor and understand that they have a genuine passion for your health. Secondly, have all relevant information and materials ready to go when you arrive.
What to Bring to the Optometrist
Information is crucial when it comes to getting the best results during an eye exam. All of the following pieces should be known or prepared before arriving:
- List of your personal medical history, including non-visual conditions
- Current ailments and a list of all medications you are taking
- Family health history, specifically in relation to eye disease (many are hereditary)
- Your most recent eyeglass or contact lens prescription, if applicable
- Your current eyeglasses or contact lenses, if applicable
- Sunglasses, if you are expecting dilation eye drops
- Personal identification and health insurance documentation
What to Expect During Vision Tests
For the initial stage, you will be answering questions about personal past, family history, and your current state of eye comfort. Your physical cooperation will be necessary to complete some of the visual tests. If you have mobility difficulties or problems moving from chair to chair, it is strongly recommended that you contact your optometry office prior to your appointment.
The average comprehensive eye exam lasts about 1 hour, start to finish. Certain condition-related tests or follow-up procedures may extend your time with a doctor. Technological advances in optometry have led to vision tests that are totally painless, and more comfortable and accurate than ever.
Types of Vision Tests
Visual testing technology has come a long way, with the introduction of 3D mapping and enhanced digital resolution. Let’s break down some typical vision tests that are part of a standard eye exam. Patients that wear contact lenses will require additional testing and fittings.
Visual Field Test
Understanding your peripheral visual abilities is important in assessing overall eye health. Peripheral vision is a measure of your ability to see things away from your line of focus. This test is non-invasive, but requires your interaction. Without complications, the process will last about 15 minutes.
You’ll look through a special machine while tracking different light sources (very soft light) and objects as they move around your field of vision. By acknowledging when and where you see peripheral images, an optometrist can build a “map” of your field of view. This helps to assess your visual health and identify any problem areas that may need further investigation.
Digital Retinal Imagery
This test gives optometrists tons of transparency about the shape, health, and strength of your eyes. Through the use of advanced imaging technology, a near-infra-red light is aimed at the back of the eye, the retina. This is totally eye-safe, and allows high resolution photos to be taken and analyzed.
Several minutes looking into a machine can potentially uncover a number of eye health risks. Images of the retina and optic nerve help identify abnormalities. This helpful technology allows you and your eye doctor to be very proactive in identifying and preventing a variety of eye diseases.
Color Blindness Test
Officially known as the Ishihara test, this effective exercise has been used for over 100 years to evaluate color blindness. Images of “colored pebble plates” are placed within a viewfinder and you will be asked to identify contrasting colors (sometimes barely perceptible). Red-green color blindness affects over 7% of men in the United States.
The Eye Chart
This is the classic eye exam we all remember from childhood. The optometrist asks you to read progressively smaller symbols from 20 feet across the room (or with the use of a mirror to simulate the distance). You cover one eye and test the strength of each individual eyeball. Eye doctors may ask you to look through a phoropter, a machine that cycles through different lens strengths.
This test is measuring visual acuity, and determining what strength of prescription will help you see the best. It is by no means invasive, only requiring your cooperation in identifying letters, numbers, and symbols.
How Vision Tests Help Your Health
After compiling all the information from various tests and questions, eye care professionals have a very clear picture of how your eyes work. Results from an eye exam provide two essential pillars of information:
- Your vision prescription
- Your ocular health
The Power of Prescriptions
If you are told you have natural 20/20 vision, congrats! You are one of the lucky ones! Only about 35% of American adults possess 20/20 vision. This number indicates that you can see something from 20 feet away that the average person can also see.
For the rest of us, vision tests provide optometrists a prescription; a reference of numbers that indicate how to best correct your eyesight. Now, keep in mind that you may have different prescriptions between your glasses and contacts. Contact wearers should always get a contact lens fitting following an eye exam.
The right vision prescription can transform your life. It improves your ability to drive, to read, to focus on a computer. It improves sports performance and helps correct your posture. It stops you from squinting and straining your neck. Two eye conditions that can be completely corrected with an accurate prescription are:
- Farsightedness (hyperopia) – an ability to see things far away, but trouble focusing on nearby objects (like reading)
- Nearsightedness (myopia) – ease of seeing things that are close, but struggling to see objects far away
Defeating Eye Disease
Regularly scheduled tests give us clues about ongoing eye health, and flag negative trends. Most eye diseases can be corrected before permanent damage occurs. This includes glaucoma, cataracts, and macular degeneration. Early diagnosis is the key factor in combating eye disease.
Eye doctors administer tests and analyze your visual records to monitor your ocular health. By combining family history with vision test results, predictions can be made to manage your visual success. Work with your optometrist to build an eye health game plan that emphasizes regular visits to the doctor.
Holistic Health Starts With Vision
Did you know that results from an eye exam provide indicators about diseases like diabetes and cancer? Vision tests can give doctors insight into high blood pressure and high cholesterol. Migraines, headaches, and fatigue can all be remedied with updated, accurate prescriptions.
Annual vision tests help you see better, which makes you feel better and look better! So if it’s been a little bit, schedule your next eye exam.