Whether you have worn glasses for years or you are getting prescription glasses for the first time, understanding your eyeglass prescription chart is essential to taking control of your everyday eye health. That starts with the SPH meaning and how to better understand your own needs.
Reading and interpreting your eyeglass prescription chart can be difficult, but the explanations below can help you figure it all out. When you can better interpret SPH and your personal chart, you can walk out of your optometrist appointment with confidence. So, let’s get into everything you need to know, starting with SPH.
What Is SPH?
Eyes are tricky, and you don’t need to be an expert to understand your eyeglass prescription chart. After all, that is what the optometrist is for! SPH is an imperative part of your chart, as it indicates whether you are farsighted or nearsighted. SPH stands for “sphere.” The Sphere (SPH) on your eyeglass prescription refers to the amount of lens that is needed to bring your vision back to normal, according to NVISION Centers. It is measured in diopters – a unit of measurement with a dimension of reciprocal length, equivalent to one reciprocal meter – and suggests that you need a spherical correction for your sight.
How To Determine SPH?
In order to determine the SPH of any given individual, doctors will start by using a specific medical device to carefully measure the curvature of your eyes and the position of your pupils. This helps to determine the placement of your meridians. According to News Medical, considering the center of the pupil as a pole, the meridians are imaginary lines drawn around the eyeball that are intersected at the poles at both anterior and posterior positions. The flattest and steepest meridians of the eye are termed the principal meridians.
Lenses are prescribed if the meridians are not properly alighted and out of place. In other words, most eyeglasses are meant to correct issues with the meridian. This is especially true for those who have astigmatism. Therefore, the spherical correction, or SPH, of your lenses also are dedicated to fixing the meridian.
In addition to SPH, there are many more abbreviations you’ll find on your eyeglasses prescription chart. These abbreviations provide you with valuable information about each one of your eyes. This information includes the amount of correction you need, the type of vision problem you are dealing with, the measurements of various distances, and other important information to ensure your best possible vision with the help of glasses.
Other Abbreviations To Know On Your Eyeglass Prescription Chart
While SPH is the dominant factor in your eyeglass prescription chart, there are many other abbreviations that may be involved. The optometrist is your guide in understanding what it all means specifically to you, but it is beneficial to have an idea of what everything stands for. Therefore, it is a good idea to know a few of the different abbreviations you might see on your chart. Here is a list of some common abbreviations that you might come across when getting new lenses or getting eyeglasses for the first time:
- OD: This stands for oculus dexter, indicating the right eye.
- OS: This stands for oculus sinister, indicating the left eye.
- OU: This stands for oculi uterque, indicating both eyes.
- PWR: Short for power, PWR can be a positive or negative number referring to the corrective lens power needed. It is closely related to SPH.
- ADD: Short for addition, ADD refers to the power that needs to be added to the lens to improve near vision.
- CYL: Short for cylinder, CYL indicates a correction for astigmatism.
- AX: An abbreviation for axis, AX is a number between 0 and 180 that indicates the angle between the two meridians of astigmatism.
- SVD: This stands for single vision distance, which is needed for the correction of distance vision only.
- SVN: This is short for single vision near, which is needed for the correction of near vision only.
- PD: This stands for pupillary distance, which represents the measurement of the distance between the center of each pupil. It is essential for creating effective and comfortable glasses.
- BVD: This is short for back vertex distance. BVD is the distance from the back of your glasses lens to the apex of your cornea, and it is adjusted to change the lens power.
Is It Time To See Your Optometrist?
If you struggle with vision and have been putting off your eye appointment, this is your sign to see an optometrist. The longer you push off your appointment, the longer you will have to deal with uncomfortable and blurry eyesight. Get the help you need, with the confidence you need, to understand your eyeglasses prescription chart and start seeing the world with a clear view.