An eye exam is essential in assessing your eye health. There are a wide variety of tests that can examine your eyes. These tests range from simple ones to more complex procedures, depending on the eye problem that you might have.
Here are some eye tests that you may encounter during a comprehensive eye exam:
1. Visual Acuity Test
An acuity test measures the sharpness of your vision. It is usually done using a projected eye chart that measures your visual acuity per distance. However, small hand-held acuity charts may also be used to test your near vision.
2. Color Blindness Test
This test is used to assess how your eyes perceive color. Color blind tests are performed to detect any eye problems that affect your color vision.
3. Cover Test
Cover test is a simple and common eye test. You will be asked to focus on an object in the room while the other eye is covered. It will be repeated while looking at near objects. If the uncovered eye moves to pick up the fixation target, it indicates a more subtle binocular vision problem or strabismus that causes amblyopia ("lazy eye") or eye strain.
4. Ocular Motility (Eye Movements) Testing
Ocular motility testing determines how your eyes can follow a moving object or quickly move between and accurately fixate on two separate targets. Eye movement problems can cause eye strain that affects reading ability, sports vision and other skills.
5. Stereopsis (Depth Perception) Test
Stereopsis is the term used to assess eye teaming that allows normal depth perception and appreciation of 3-dimensional natures of objects.
While wearing a pair of "3D" glasses, you will be asked to point out in a pattern which circle is closer to you. If you can correctly identify the "closer" circle in each pattern, it means that you have excellent eye teaming skills that will enable you to experience normal depth perception.
Retinoscopy is performed to assess your eyeglass prescription. This test is useful for patients who are unable to answer doctor’s questions regarding vision.
The room lights will be dimmed and you will be asked to focus on a big “E” located the eye chart. While staring at it, the doctor will flash a light on your eye and flip the lenses in a machine that is in front of your eyes. This machine will estimate which lens power best suits your distant vision.
Refraction is a test to determine your exact eyeglass prescription. It also determines the level of hyperopia (farsightedness), myopia (nearsightedness), presbyopia and astigmatism.
A phoropter will be placed in front of your eyes and you will be shown a series of lens choices until reaching a final eyeglass prescription based on your answers.
8. The Glaucoma Test
Testing glaucoma begins with the measurement of the pressure within your eyes.
Non-contact tonometry or NCT, is a common glaucoma test. Your chin will be placed on a machine’s chin rest and the doctor will then puff a small burst of air at your open eye. The machine will then calculate your intraocular pressure (IOP).
If you have high eye pressure that is determined by a tonometer, you most likely have glaucoma.
The applanation tonometer is mounted on a slit lamp. Yellow eye drops will be applied to your eyes to numb them and you will be asked to look straight into the slit lamp while the doctor touches the surface of your eye with a tonometer to measure your eye pressure.
9. Pupil Dilation
Dilating drops will be applied to your eyes to enlarge your pupils. This is done so that doctors could see the internal structure of your eyes. After 20 to 30 minutes, you will experience sensitivity to light and you may even have difficulty in focusing on objects up close.
Pupil dilation is important in having a thorough evaluation of your eyes. Various instruments will be used to examine your eyes thereafter.
10. Visual Field Test
By performing a visual field test, the doctor can check for the presence of blind spots (scotomas) in your peripheral or "side" vision. Blind spots may occur due to eye diseases such as glaucoma.
Blind spot analysis also helps identify specific areas of brain damage that are affected by a stroke or a tumor.
Visit your ophthalmologist now to know more!
Reference: Gary Heiting O. What To Expect During A Comprehensive Eye Exam. All About Vision. https://www.allaboutvision.com/eye-exam/expect.htm. Published 2018. Accessed November 21, 2018.