When it comes to buying prescription eyewear, understanding your prescription is the first step to finding the perfect pair of glasses or sunglasses. Whether you’re new to wearing glasses or have been rocking them for years, a prescription can seem a bit confusing at first. But don’t worry! In this post, we’ll break down the key components of your prescription, so you can make informed decisions when shopping for your next pair of frames.

 

What’s in Your Prescription?

A typical eyeglass prescription contains several key pieces of information. Here’s a breakdown of the most common elements:

 

OD (Right Eye) and OS (Left Eye)

These terms represent each eye's prescription. OD stands for oculus dexter, which is the right eye, and OS stands for oculus sinister, which is the left eye. When reviewing your prescription, always look at the measurements for both eyes individually.

Sphere (SPH)

The sphere indicates the degree of nearsightedness (myopia) or farsightedness (hyperopia) you have. If the number is preceded by a minus sign (-), it means you are nearsighted (you have trouble seeing things at a distance). If it’s preceded by a plus sign (+), you are farsighted (you struggle to see things up close).

Cylinder (CYL)

The cylinder refers to the degree of astigmatism, which is an imperfection in the shape of your eye’s cornea. If you have a cylinder number, it means you have some astigmatism. Like the sphere measurement, it can also have a minus or plus sign depending on whether your astigmatism is nearsighted or farsighted.

Axis

The axis is the angle in degrees (ranging from 0 to 180) where your astigmatism is located. It tells the optometrist how to align the cylindrical correction of your glasses. If your prescription includes a cylinder, it will likely also include an axis number.

Add (Near Vision)

This refers to the additional magnification needed for reading or seeing up close, typically for people over 40 who require reading glasses or multifocal lenses. This measurement is common for bifocals or progressive lenses.

Prism

The prism helps correct eye alignment issues (like strabismus). It indicates how much light needs to be bent to help your eyes focus properly. If you have a prism value in your prescription, it will show the strength and direction needed.

PD (Pupillary Distance)

Pupillary Distance (PD) is the distance between the centers of your pupils, measured in millimeters. It ensures that your lenses are properly aligned with your eyes for clear, comfortable vision. PD is essential for custom eyewear, especially when ordering online. If your prescription doesn’t include it, you can easily ask your optometrist or measure it yourself. Check out our guide for step-by-step instructions on how to measure your PD to ensure your lenses are perfectly centered in your frames:

How to Measure Your Pupillary Distance (PD) At Home

 

How to Read Your Prescription: Example Breakdown

Here’s an example of what a typical prescription might look like:

OD (Right Eye)	OS (Left Eye)
SPH: -2.00	SPH: -1.50
CYL: -1.00	CYL: -0.75
Axis: 180	Axis: 90
Add: +2.00	Add: +2.00

 

In this example:

• Right Eye (OD) has -2.00 for nearsightedness, with -1.00 of astigmatism and an axis of 180 degrees.
• Left Eye (OS) has -1.50 for nearsightedness, with -0.75 of astigmatism and an axis of 90 degrees.
• The Add value of +2.00 indicates the added magnification for reading (typically for a multifocal lens).

 

Choosing the Right Lens Based on Prescription Strength

Selecting the right lens material is crucial not only for vision clarity but also for comfort and aesthetics, especially if you have a strong prescription. Stronger prescriptions tend to require thicker lenses, which can be heavier and more prone to distortion. Choosing the right lens index ensures your glasses remain lightweight, durable, and visually appealing. Here's a breakdown of how different lens materials match with varying prescription strengths:

 

Lens Index	SPH	CYL
1.50 Standard Index Lens	0 to +/- 2.0	0 to +/- 1.5
1.56 Mid-Index Lens	0 to +/- 2.0	0 to +/- 1.5
1.59 Polycarbonate Impact Resistant	2.0 to +/- 4.0	1.5 to +/- 2.0
1.61 High-Index Lens	4.0 to +/- 6.0	2.25 to +/- 3.0
1.67 High-Index Lens	6.0 to +/- 9.0	3.25 to +/- 4.0
1.74 High-Index Lens	above +/- 9.25	above +/- 4.25

 

 

Choosing the Right Frames Based on Your Prescription

Understanding your prescription is just the first step! Once you know the details of your vision needs, you can make more informed choices when selecting your eyewear. Here are a few tips on choosing frames based on your prescription:

 

For Strong Prescriptions

If you have a high prescription, opt for thicker, sturdier frames to help prevent distortion. Frames with a wider bridge and deeper lenses can help balance the thickness of the lens and ensure comfort.

For Astigmatism

If your prescription includes cylinder measurements for astigmatism, consider frames that provide a larger lens area to ensure proper alignment. Rounded or oval-shaped frames can work well for astigmatism.

For Bifocals or Progressives

If you need multifocal lenses, be sure to choose frames that allow for enough height to accommodate both near and distance vision. Full-frame or semi-rimless designs work best for these types of lenses.

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Conclusion: Make Your Prescription Work for You

At Specstyler, we believe that understanding your prescription is key to finding eyewear that not only corrects your vision but also reflects your personal style. Whether you're shopping for prescription glasses, reading glasses, or sunglasses, knowing the details of your prescription will help you make the best choice for comfort and clarity.

Need help selecting the perfect pair? Our team is here to guide you through the process. Browse our wide range of stylish, high-quality frames today and find the perfect match for your prescription!