Decoding Your Vision: The Ultimate Guide to Reading Your Eye Prescription

At first glance, understanding your eye prescription can feel like decoding a cryptic message. However, it’s important to grasp the significance of those numbers and symbols to ensure you’re getting the correct eyewear for all your vision needs. Whether you’re nearsighted, farsighted, or have astigmatism, this comprehensive guide will help demystify the jargon and empower you to read your eye prescription with confidence.

Understanding the Basics

Before diving into the specifics, let’s start with the fundamentals. An eye prescription typically consists of several abbreviations, such as OD and OS, which stand for Oculus Dexter (right eye) and Oculus Sinister (left eye), respectively. These abbreviations help differentiate between prescriptions for each eye.

Reading the Numbers

Your prescription can also contain measurements such as Sphere (SPH), Cylinder (CYL), and Axis, which determine the type and degree of your vision correction. Here’s what they mean:

Sphere (SPH): Its number indicates the degree of nearsightedness (negative number) or farsightedness (positive number). A higher SPH number means a stronger prescription.

Cylinder (CYL): The cylinder number indicates how much astigmatism you have. This is when part of the cornea has a different curve. The eye is usually shaped like a round ball and maintains its curve no matter which direction it rotates. An astigmatic eye has an oval shape, meaning one curve is longer than the other. The job of the CYL number is to correct the differing second curve. 

Axis: Written in degrees between 1 and 180, the Axis number tells you where the astigmatism is on the cornea and in which direction the astigmatism lines up. 

Sometimes, not always, these numbers may be found on your prescription:

Add: In the case of presbyopia, or the farsightedness that naturally comes along with age, Add is the magnifying power that is added to the bottom half of multifocal ophthalmic lenses.

Prism: If you have binocular vision or eye alignment issues, Prism correction may be prescribed to help align your eyes properly.

Sphere, cylinder, and add are always measured in “diopters”, come in decimal form, and are generally written in increments of 0.25 D.

As for the prism, its diopters are also measured in decimal form, but with one number appearing after the period (for example: 0.5 D).

Interpreting Your Prescription

If this is still confusing, let us show you how to interpret your prescription with an example:

OD: -2.00 -1.00 x 180

OS: -1.75 -0.75 x 170

Here, the right eye (OD) has a Sphere of -2.00 D, with a Cylinder of -1.00 D at an Axis of 180 degrees. The left eye (OS) has a Sphere of -1.75 D, with a Cylinder of -0.75 D at an Axis of 170 degrees.

Consulting an Optometrist

While understanding your eye prescription is important, it’s essential to pair that with a consultation from a qualified optometrist or ophthalmologist, who can perform a comprehensive eye test. Your eye health and vision are unique, and professional guidance ensures that your prescription accurately addresses your needs.

Now, armed with your eye prescription, you’re ready to explore a wide range of eyewear options. Whether you prefer eyeglasses or contact lenses, selecting the right lenses and frames tailored to your prescription just got easier. You can also consider factors such as lens material, coatings, and frame styles to enhance both your vision and personal style. Here at MAGRABi, we have our ophthalmic lens brand Zwei, made with advanced German technology, that can cater to your optical lens needs.

Additionally, it’s important to have annual eye tests to maintain healthy eyesight, so schedule your next free appointment with our team of experts at your nearest MAGRABi store and continue prioritizing your visual well-being.