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Prescription Guide

How to Read Your Prescription?

You need regular eye exams to keep your vision and eye healthy. An ophthalmologist, optometrist, or eye doctor will check your eyes and look for any indications of an eye condition. You will receive a prescription if you need contact lenses or glasses to fix your vision. However, it could be challenging to comprehend eyeglass prescriptions.

They typically consist of a combination of letters and numbers, which can be perplexing if you don't know what they imply. It will be easier to understand any acronyms and figures in your eye prescription with the help of this article. Additionally, it will clarify how your eye condition may affect a prescription's strength. This guide will help you get proper awareness.

Abbreviations in Latin

Professionals who write prescriptions for eyeglasses accept Latin abbreviations. Latin acronyms are becoming less common despite being in use for a very long time. Acronyms for specific phrases can be found on your prescription. For instance, the word "sphere" can also appear on prescriptions as "SPH." The word "power" can also be spelled as "PWR."

Numbers Shown on Prescription

Your prescription contains several acronyms and numeric values. The eyeglasses maker will use your prescription data to calculate the amount of vision correction you need. In diopters, the strength of eyewear is expressed. You are farsighted if the numbers are shown with a plus sign (+) or without one. If the numbers have a minus sign (-) next to them, you are near-sighted.

If your prescription has a near-sightedness component of -1.00, you must wear glasses with a 1 diopter strength. You will need glasses with a 2.5 diopter strength if your prescription is +2.50 to correct your farsightedness. The need for eyesight correction is rising in tandem with population growth.

How to Calculate Myopia?

Near-sightedness, often known as myopia, is a common refractive disorder. When you have near-sightedness, distant objects look blurry, but they are easy to see up close. When you are near-sighted, the distance between the retina in the back of your eye and the cornea at the front of your eye is too great.

A very curved cornea is another component that causes near-sightedness. The increased distance means that the retina, a light-sensitive organ communicating with your brain, is no longer directly in the path of light rays. As a result, you can experience fuzzy distance vision.

How to Calculate Long-Sightedness?

Hyperopia, another name for farsightedness, is a refractive condition that impairs near vision more than far vision. It occurs when your cornea is not sufficiently curled or when your cornea and retina are too close. Farsightedness causes light to be directed behind your retina rather than directly on it.

The strength of the lenses will be indicated with a plus sign for a farsighted prescription. The figures will be higher the wiser you are. For instance, a prescription for stronger glasses than one for weaker ones is +4.50.

The Astigmatism Treatments You Should be Aware of

Astigmatism is a variation from the natural shape of your eye's cornea or lens. The asymmetrical curve with which light enters your eye may make it take longer for it to reach your retina. Astigmatism can cause visual distortion for both adjacent and distant objects. Also possible is a distorted image.

Astigmatism is present, as is typical. If your astigmatism is 1.5 diopters or more, you might need to use prescription glasses or contact lenses to see clearly. However, if you have astigmatism, glasses may help you see better.

Your prescription for eyeglasses may also contain the terms or abbreviations listed below:

You only need glasses for closed eyesight, according to SVD (for distance vision correction only)

The distance between the centers of the two pupils in each of your eyes is known as the pupillary distance or PD. Your supplier will use this measurement to guarantee that your glasses are the ideal size for ergonomics and vision.

Prism: For people with strabismus or other abnormalities with their focusing or eye muscles, this assessment is frequently all that is necessary. This measurement directs the path of the picture through the lens of the glasses in a particular manner.

OD, your right eye. The acronym for OD is oculus dexter, which is Latin for "right eye." Dexterity and dextrous have a similar root.

OS, your left eye. OS stands for Oculus Sinister, which is Latin for "left eye." We assure you that the difference between your left and right eyes does not reflect moral depravity; the word just denotes orientation. Those are both of your eyes.

OU stands for Oculus uterque, meaning "two eyes" in Latin.

Near Vision (ND) - Seeing things close-up

Distance Vision (DV) – Looking at things from far away

SPH – It denotes Sphere, which refers to the fact that the near- or farsightedness correction is spherical, i.e., that it is uniform along all meridian lines of the eye.

A diopter is any smaller number in your eye prescription's "Sphere" or "Cyl" columns. Similar to a gram or an ounce, a diopter is a unit of measurement. However, diopters measure a lens' refractive power rather than its mass.

You will see more significant numbers if your prescription is higher (greater optical power!). Additionally, you will see lower numbers if you don't need as many contacts or glasses.


Symptoms like double vision may appear when eyes don't move in unison. The disorder known as strabismus, or "crossed eyes," is one that causes eye misalignment.

To address this issue, your doctor can add a prism to your lenses. The position and orientation of the prism are determined by your prescription, which also controls the direction of the thickest edge or base.

BI: Bases In

BO: Bases Out

BU: Bases Up

BD: Bases Down

The prism will also have its own refractive power, which is measured in prism diopters.

How to Check the Expiry Date?

Your eye prescription won't remain the same forever. So, it's important to get frequent eye exams to ensure your eyesight is as straightforward as possible.

Ordinarily, eye prescriptions are valid for one to two years before they expire. There can be variation in the exact time period based on state laws. You will then need to arrange an eye exam to renew it.

Will Your Eyeglass Prescription Change?

You should have your eyesight prescription checked if you detect any major changes over time (unless they are expected side effects of a treatment or an injury). However, as you age and your eyes evolve, gradual, subtle alterations could take place.

You should have your eyes checked annually, even if you don't think your vision has changed and you don't experience any alarming symptoms. An optometrist can monitor your eyesight and adjust your prescription as necessary with a yearly eye exam.

When scheduling your eye test, let your eye doctor know if you want to wear contacts in place of (or in addition to) glasses. They will be notified that a contact lens fitting should be provided so they may evaluate the comfort and vision of the contacts.


Latin letters, numerals, and mathematical symbols could be included in your prescription for glasses. These figures represent the shape of your eyes and the degree of correction your glasses should offer.