More than 2.3 billion people in the world have refraction errors. An ophthalmologist or optometrist performs the refraction test during a routine eye exam. The purpose of a refraction test is to determine the perfect prescription for your eyes when getting glasses or contact lenses.
When taking the exam, you are seated in a chair with a special device attached called a refractor or phoropter. As you look through the device, you are focused on an eye chart that is 20 feet away. The refractor or phoropter contains lenses with various strengths to see which is best suited to improve your eyesight. This exam will be performed on one eye at a time.
During the exam, the eye doctor will alternate the lenses and ask which one appears more or less clear. The results of the exam will differ depending on your responses.
Then, a specialized light will shine into your eyes. The purpose of this light is to determine your refraction. You will not need to respond to this part of the exam. There are different benefits to different types of refractions.
Reason for the Refraction Test
A refraction test can be done as part of a routine eye exam. The purpose of the exam is to determine whether or not you have a refraction error. A refraction error can result in the need for glasses or contact lenses. This test can also be done to improve previous prescriptions as your eyesight changes over time.
Once you have reached the age of 40, if you have normal distance vision, but difficulty with near vision, a refraction test will help determine the need for reading glasses. It will also determine which strength of reading glasses is right for you.
How to Prepare
In order to prepare for the retraction test, if you wear contacts, ask your eye doctor if you need to remove them prior to the exam. If your doctor says yes, ask how long they recommend keeping your contacts out.
Many people are nervous if the exam will cause any discomfort, but you should not feel anything. As a result, there are no risks in participating in this exam.
If your normal vision without contact lenses or glasses is normal, then your results will state your reactive error is zero (Plano) which means your vision is 20/20 (6/6). As a result, this means you can read ⅜-inch or 1-centimeter letters at a distance of 20 feet. Another way to determine whether or not you have normal vision is the ability to reach small type sizes.
If you have a refraction error then you would need a combination of lenses from the exam to have 20/20 vision. Glasses or contact lenses would be the solution to improve your vision. Sometimes even surgery is a way to improve a refraction error. However, a refractive error helps create your prescription for lenses. A prescription is made up of a series of numbers that describe the power of the lenses needed for you to see clearly.
After you have received your lenses, and your vision is still less than 20/20, then there is probably another non-optical problem with your eyes.
The result of the vision level you achieve during the refraction test is called the best-corrected visual acuity (BCVA).
Abnormal results include:
- Astigmatism: abnormally curved cornea causing blurred vision
- Hyperopia: farsightedness
- Myopia: nearsightedness
- Presbyopia: inability to focus on near objects that develop with age
After the age of 40 (or for people with a family history of glaucoma), eye exams should be scheduled annually.
How We Can Help!
At Medical Arts and Eyes, we want to make sure your vision is 20/20! Whether that is with glasses, contacts, or eye surgery, we are able to accommodate you in the best way! If you are in need of glasses after a refraction exam, we have many different kinds of frames for you to choose from which will make your visit to the eye doctor even easier! Contact us today and we can schedule an appointment at your convenience!