If you haven’t been for a while, or have never had a comprehensive eye exam, you may not be sure what to expect. There are a wide variety of tests and procedures that eye doctors use to examine your eyes and vision.
Eye exams typically take about an hour or longer, and the types of tests performed at each one vary. Below, you’ll learn what tests to expect, and what is done during each one.
Know Your History
It’s important to have at least a general idea of your family’s history when it comes to vision and overall eye health. If your optometrist knows what may have occurred in the past, they may be able to more specifically identify your individual needs, and spot potential indicators of certain conditions.
This doesn’t mean that the examination will only focus on those specific points, but rather that it will allow the optometrist to be more efficient in their approach and diagnoses.
Which Tests Are Involved?
An eye exam involves the testing of your visual acuity using an eye chart, and several other tests. Some are simple and some are more complex, but all serve a very specific purpose – to assist in determining your eye care needs.
Once these tests are completed, the optometrist will identify if you require any vision correction, or if certain symptoms need to be monitored in any way. Some examples of tests performed during an eye exam are:
Visual Acuity Test
This test is performed to determine the “sharpness” of your vision and is often completed while you are sitting still, while the letters and numbers that you are viewing remain stationary. Acuity is also measured under high contrast conditions, for example, the letters and numbers on the chart you may be viewing are black, and the background is white.
This method of testing is fairly effective at determining the relative clarity of your eyesight, but will not showcase the true quality of your vision under all conditions, for example, predicting how well you see:
- Objects similar in brightness to their background
- Moving objects
- Colored objects
Visual acuity is where you often hear the term “20/20 vision” as it is quantified by these Snellen fractions.
Color Blindness Test
There are 2 main types of color-blind tests: they are screening tests and quantitative tests. These are typically used early on during your comprehensive eye exam. They identify whether or not you can see color as most people do, or the severity of potential color blindness.
Screening tests use what’s called an Ishihara Color Vision Test, which consists of a booklet containing multiple pages with multiple colored dots on each page of various brightness and sizes.
Quantitative tests provide a more detailed analysis of color blindness, and an individual’s ability to accurately perceive colors. One of the most popular quantitative tests is the Farnsworth-Munsell 100 Hue Test.
Cover Test
Often the simplest and most common method in determining how your eyes work together.
Your eye doctor will ask you to focus on a small object that is across the room, while covering each of your eyes alternately.
They will then perform this same method with a near object. While you are focussing on the object, they will observe whether the uncovered eye must move to refocus onto the target, potentially indicating strabismus, amblyopia, or other potential conditions.
Ocular Motility Testing
This testing is done to determine how well your eyes can follow moving objects, as well as how quickly they can focus on fixed objects that are some distance apart. Your eye doctor will typically have you follow a light or a target, while you hold your head still, and monitor your eye movements.
Problems with eye movement may cause strain, issues with reading ability, and be detrimental to the formation of other skills.
Stereopsis Test
This test is done to determine if you experience normal depth perception. In one commonly used stereopsis test, the eye doctor will have you wear “3D” glasses to view a booklet of test patterns.
Each pattern will have 4 small circles, and if you can identify which of the circles appears “closer” to you out of the group, you are experiencing normal depth perception.
Retinoscopy
When a retinoscopy is performed, it allows your eye doctor to provide an estimation of your eyeglass prescription. The room will more than likely have dim light, and they will ask you to focus on the letter “E” on the Snellen chart for example.
While you remain focused, they will flip between different lenses to determine the way light reflects from your eye. Based on their determination, they can approximate the power of eyeglasses potentially required to correct your vision.
Refraction
Your doctor will use this method of testing to determine your exact eyeglass prescription. During the refraction, the doctor puts a phoropter in front of your eyes to present a series of lens choices.
They will then ask you which of the lens choices looks clearer and fine-tune the lens power until reaching a final eyeglass prescription. This test determines your level of hyperopia, myopia, astigmatism, or presbyopia.
Eye Pressure Testing
2 common methods of testing are:
- NCT (non-contact tonometry)
- Applanation Tonometer
Both of these methods of examination, among others, are completely painless and are important in identifying potential warning signs of glaucoma.
Do Exams Differ as We Age?
If you are generally healthy and are not experiencing any symptoms of vision problems, it is believed that you should have your eyes checked annually.
As we age, the frequency of examination may increase, simply because our eyes and vision are changing as time goes on. Examinations differ from doctor to doctor, and types of testing vary depending on who you see.
In general, the more the merrier, the older you get. This will assist in identifying any difficulties that require attention or correction, as well as providing peace of mind in knowing that you are doing everything possible to mitigate the risk of conditions such as cataracts, glaucoma, diabetic retinopathy, and age-related macular degeneration.
Eye exams are thorough, given the short amount of time that it generally takes to complete, and are very important to your overall health and well-being. With a large variance in the types and methods of testing available, feel free to ask your eye doctor any detailed questions you may have before going in for your next visit.
