Life these days can be visually demanding. However, with some help from your glasses, you can make the world a little clearer. But how much help are your glasses actually providing? Understanding your glasses prescription can give you insight into what exactly is going on behind—and in front of—your eyes.
Your optometrist determines your prescription during an eye exam. A strong glasses prescription is usually when nearsightedness is -5.00 diopters or more or farsightedness is +5.00 diopters or more. Everyone’s vision is a little different, so don’t worry if you need a stronger prescription than your friend. What matters is that it’s right for you, so that you can get out there and enjoy life!
What Is a Glasses Prescription?
A prescription for glasses is a written order by an optometrist that specifies the type of lens correction needed to correct your vision. It serves as a blueprint for your eyewear, guiding an optician so they can find you lenses tailored specifically to your eyes. Without a prescription, your glasses may not provide the necessary correction, which could make wearing your glasses a pain.
Reading Your Prescription
Prescriptions for glasses can be confusing if you’ve never seen one before. They contain several numbers and abbreviations that may seem overwhelming at first glance. However, once you understand what each number represents, it becomes much more straightforward.
Sphere (SPH)
The sphere measurement indicates the amount of lens power needed to correct nearsightedness or farsightedness. This is one of the key factors you should look at to determine if your prescription is strong.
Lens power is measured in diopters, representing the degree of vision correction you need. This number is preceded by either a minus sign (-) for nearsightedness or a plus sign (+) for farsightedness. Remember, these aren’t exactly positive or negative numbers! Whether it has a minus or a plus sign, a higher number equals a stronger prescription.
Cylinder (CYL)
If you have astigmatism, this means that your eyes aren’t perfectly round. Astigmatism can cause blurred or distorted vision separate from your other vision problems. The cylinder measurement indicates how much astigmatism you have. The higher the CYL number, the greater your astigmatism and, therefore, the stronger your prescription is likely to be.
Since it’s possible to have astigmatism alongside near or farsightedness, you’ll need to take both your CYL and your SPH into consideration when examining your prescription strength.
Axis
The axis measurement works in conjunction with the cylinder value and specifies your astigmatism’s orientation in degrees, from 0 to 180.
Other Abbreviations
While these are the main features you’ll want to look for, you may find some other abbreviations on your prescription that are worth knowing, including:
- OD (Oculus Dexter): This is just the Latin phrase for “right eye.”
- OS (Oculus Sinister): As you may expect, the Latin phrase for “left eye.”
- PD (Pupillary Distance): the space between your pupils, measured in millimeters. It helps your glasses lenses line up with your eyes.
- ADD (Addition): This is an extra boost of lens power at the bottom of multifocal lenses, helping you see better up close, especially if you’re dealing with presbyopia.
- Prism: If you have double vision or eye alignment issues, prism correction can help. It tweaks how light enters your eyes, using numbers and directions (like “base up” or “base down”) to get things just right.
Example Prescriptions
Let’s look at a couple of prescription examples you may encounter:
Example 1:
- OD: SPH +1.25, CYL -1.00, Axis 45, ADD +2.00
- OS: SPH +1.50, CYL -0.50, Axis 40, ADD +2.00
In this example, the person is farsighted with 1.25 diopters in the right eye and 1.50 diopters in the left. Yes, it’s perfectly normal to have slightly different prescriptions for each eye! This person also had some astigmatism and will get multifocal glasses with +2.00 ADD to help them read or do any near tasks.
Example 2:
- OD: SPH -7.00, CYL -2.00, Axis 90
- OS: SPH -7.00, CYL -2.50, Axis 85
This prescription is much stronger but for a different condition. Both eyes require a -7.00 diopter correction for significant nearsightedness. This person also requires around -2.00 correction for their astigmatism, but they don’t need any additional magnification.
A “strong prescription” is generally considered any prescription over 5.00 diopters. That’s over -5.00 for nearsightedness and over +5.00 for farsightedness. A sphere of 0.00 would likely be considered “perfect vision.”
How Often Do You Need to Update Your Prescription?
You’ll probably also notice a date on your prescription. This is its expiration date. Usually, a prescription is valid for 1–2 years. However, this can vary based on individual circumstances, and an expiration date is not a promise—it’s a guideline.
Children’s eyes can change rapidly, so they may need more frequent prescription updates. Similarly, seniors whose vision is deteriorating benefit from a yearly check-up.
If you notice any vision changes or your glasses don’t seem to be as effective as they once were, you don’t have to wait until the expiration date to get your eyes checked. Visit your optometrist as soon as you can for an eye exam. These exams can also uncover early signs of eye disease that may slip under the radar.
Your Vision Is Our Priority
Whether your prescription is weak or strong, regular eye exams for up-to-date prescriptions help you see the world as it’s meant to be seen.
Whether it’s time for your next eye exam, or if you’ve noticed any changes in your vision, don’t hesitate to schedule an appointment with Total Vision Sports Arena. Our team is dedicated to your vision, offering eye care you can trust with personalized service that prioritizes your well-being.Book an appointment today and see the difference we can make in your vision care!
