If you wear glasses or contact lenses, you've probably received a prescription from your optometrist or ophthalmologist. However, understanding what all the numbers and abbreviations mean can be confusing. In this article, we will explain how to read your prescription in simple terms.
Understanding Your Prescription
The Basics
Your prescription will include your name, the date of the exam, and the name, address, and phone number of the prescribing doctor. It will also include the following terms:
- OD and OS: These are abbreviations for the Latin words Oculus Dexter and Oculus Sinister, which mean right eye and left eye, respectively.
- Sphere (SPH): This number indicates the degree of nearsightedness or farsightedness you have. A negative number means you are nearsighted, and a positive number means you are farsighted.
- Cylinder (CYL): This number indicates the amount of astigmatism you have, which is a common condition that causes blurred vision. It is usually accompanied by an axis measurement.
- Axis: This measurement tells the orientation of the cylinder and is expressed in degrees from 0 to 180.
- Addition (ADD): This number is used for bifocal or progressive lenses and indicates the additional magnifying power in the lower part of the lens for reading or close work.
Example Prescription
Here's an example prescription:
| OD | OS | |
|---|---|---|
| Sphere | -2.50 | -3.00 |
| Cylinder | -0.75 | -1.25 |
| Axis | 180 | 10 |
This prescription indicates that the patient has a moderate degree of nearsightedness in both eyes, with some astigmatism in the right eye (OD) and more in the left eye (OS). The axis measurement for the right eye is 180 degrees, meaning the astigmatism is horizontal, while the axis for the left eye is 10 degrees, indicating a slightly oblique orientation.
Interpreting Your Prescription
To understand what your prescription means for your eyeglasses or contact lenses, you will need to consult with an optical professional. They will use your prescription to determine the appropriate lens power, lens material, and lens design to meet your needs.
Eyeglasses
If you wear eyeglasses, your prescription will determine the lens power for each eye. The lens material and design will depend on your preferences and needs, such as the type of frames you choose and your lifestyle.
Contact Lenses
If you wear contact lenses, your prescription will determine the base curve and diameter of the lenses, as well as the lens power. It will also indicate whether you need toric lenses for astigmatism or multifocal lenses for presbyopia. When purchasing contact lenses, it's best to keep a reference of your prescription to present to an optician or optical professional. There are some resources online to help interpret your prescription, you can also upload an image of your prescription at contactshub.ca and we will explain them to you!
Tips for Reading Your Prescription
Here are some tips to keep in mind when reading your prescription:
- Ask your doctor to explain any terms or abbreviations you don't understand.
- Keep a copy of your prescription for reference when ordering eyeglasses or contact lenses.
- Make sure your prescription is current, as your vision can change over time.
- Send us an email or upload your prescription to contactshub.ca and have licensed opticians explained them to you.
Conclusion
Understanding your prescription is an essential step in obtaining the correct eyeglasses or contact lenses for your vision needs. By learning what the numbers and abbreviations mean, you can make informed decisions about your eye care.
FAQs
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How often should I get my prescription checked?
It is recommended to get your prescription checked every year or as often as your eye doctor recommends.
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What is the difference between nearsightedness and farsightedness?
Nearsightedness (myopia) is a condition where distant objects appear blurry, while farsightedness (hyperopia) is a condition where close objects appear blurry.
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Can I order eyeglasses or contact lenses without a prescription?
No, it is not legal to purchase corrective eyewear without a prescription from a licensed optometrist or ophthalmologist.
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What should I do if my prescription changes?
If your prescription changes, you should schedule an appointment with your eye doctor to get a new prescription and update your corrective eyewear accordingly.
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Can I use my old prescription to order new eyeglasses or contact lenses?
It is not recommended to use an outdated prescription to order new eyewear, as your vision needs may have changed. It is always best to get a new prescription from your eye doctor to ensure the most accurate correction.