You just got your prescription and you’re wondering how this jumble of letters and numbers will help improve your vision. You might ask questions like, what do these values mean on my prescription? Eyeglass prescriptions help your eye care professional understand how well your eyes work and what types and powers of lenses, including spherical and cylindrical, are needed to make up for your eye defects. This begins with a comprehensive eye exam.
Optical prescriptions have a lot of abbreviations and terms like SPH, AXIS, PRISM, and BASE. CYL and AXIS values are prescription metrics that combine to correct astigmatism—blurry and distorted vision at any distance caused by irregular eye shape. You may have come across these terms like cylinder and sphere and been confused about their importance. Today’s blog post will give you clarity on it and how it affects your prescription and vision.
What Does AXIS Mean On My Eye Prescription?
To fully understand it, you also need to understand the CYL value, as both work hand in hand to correct the same defect.
The CYL values show how much cylindrical power, measured in diopters (D), is needed to rectify astigmatism. These can include minus values for those who are nearsighted. The AXIS number indicates the angle or meridian at which the cylindrical lens must sit with respect to the eye to provide you with the proper amount of lens power.
Axis values range from 1 to 180 degrees. A 90 value shows a vertically placed cylindrical lens, while a 180 reading shows a horizontally placed cylindrical lens.
A high axis value does not affect the strength or corrective power of the lens; it just shows how it is to be positioned.
Example of a Cylindrical Lens Prescription with AXIS Reading:
| CYL | AXIS | |
| OD (Right Eye) | -1.25 | 125 |
| OS (Left Eye) | -1.00 | 79 |
This eye prescription shows:
- A cylindrical lens of -1.25 D, placed at 125° meridian is needed to correct astigmatism in the right eye. This correction involves the cylinder power for precise vision adjustment.
- A cylindrical lens of -1.00 D, placed at 79° is needed to rectify astigmatism in the left eye.
Some Other Terminologies and What They Mean on My Prescription and Eye Test?
When AXIS is on your prescription, understanding what it means is easier if you are aware of other terminologies that may also appear. Each number on your eye prescription has a specific meaning and purpose. Here’s a breakdown of the key terms you might find on your prescription for glasses:
- SPH (Sphere): This value indicates the sphere power needed to correct nearsightedness or farsightedness. A negative SPH value corrects nearsightedness, while a positive value corrects farsightedness.
- CYL (Cylinder): The CYL value shows the amount of cylindrical power needed to rectify astigmatism, which is caused by an irregularly shaped cornea. Both the SPH and the CYL are measured in diopters.
- Add (Addition): This value is used for bifocal or progressive lenses, indicating the additional magnifying power needed for reading or close-up vision.
- PD (Pupillary Distance): This measurement is the distance between your pupils, used to ensure that the lenses are correctly centered in front of your eyes.
SPH (Sphere), CYL (Cylinder), Contact Lenses, and Astigmatism Correction
For those transitioning between eyeglasses and contact lenses, it’s important to note that while both use the SPH value (Sphere) to indicate the lens power needed for vision correction, lenses often require additional measurements for a perfect fit. These include the base curve, which matches the curvature of your cornea, and the diameter of the lens. Unlike glasses, lenses sit directly on the eye, necessitating precise fitting to ensure comfort and optimal vision. But both of them use cylindrical power for astigmatism correction. In eyeglasses, the cylindrical power and axis values indicate the orientation and strength of the corrective lens needed. In contact lenses, similar values are used but need to be precisely fitted due to the direct contact with the eye.
Effects of Wrong AXIS Values on My Eye Health
When you read your prescription, it’s important to note the AXIS values as they are crucial parts of your prescription and should be measured precisely. The slightest error in the axis eye value will result in the cylinder power being applied to areas of your eyes that don’t need correction for astigmatism. This means that the correction will be misaligned, causing symptoms like blurred vision and eye strain. This is why your prescription includes such specific measurements. The misalignment may cause symptoms like:
- Blurred and distorted vision due to uncorrected astigmatism.
- Eye strain and headaches due to your eyes working harder to look through misaligned lenses.
- Dizziness and nausea while trying to shift your gaze from object to object.
- Wrong perception of distance and depth might require a correction in diopter or cylinder values.
- Reduced sharpness and clarity.
How to Get My Precise AXIS Value
To get your accurate axis eye prescription, we advise that you visit a reputable eye clinic, get tests done, and get a prescription. Knowing how to read your eyeglass prescription can help you verify the accuracy of the provided details. We also have to remind you that your vision may change gradually over time, and children may even outgrow slight astigmatism. As such, we advise you to take routine eye tests—once every two years—to keep track of your CYL correction and AXIS value and make necessary adjustments to your eye care options if any changes are noticed.
After obtaining a prescription, next on your agenda should be getting fitted with the right pair of glasses for you. Proper vision is essential for optimal comfort and clarity.
Getting the Right Pair of Prescription for My Eyeglasses
The first step to helping us fit you with the perfect pair of glasses is to pick out the right frames and lenses, based on your glasses prescription. This can prove to be a headache, especially when you are concerned about correcting near vision or distance vision. We’ve got you covered with a wide selection of eyewear options.
We have a wide selection of frame types and shapes in stock for your vision correction needs; one is sure to catch your eye. Read through our frame guide for more information before making a choice. After picking out a frame that appeals to you, you can get the option to upload your picture and virtually try it on. This helps ensure that your corrective lenses will be accurately positioned.
Tell us your needs by entering your optical prescription and pupillary distance. This guarantees that you will receive designs specifically tailored to you. You can also choose to add perks like scratch resistance, a blue light filter, or photochrome to your contact . Your prescription must be issued within the last two years for you to be able to order your glasses from us.
Proceed to the check-out page, fill in your shipping address and billing details, and add a coupon code if you have one. Sit back, relax, and your personalized glasses will be at your doorstep in a few days.
