How Do You Read Glasses Prescription: Ultimate Guide

Regular eye check-ups are vital for keeping your eyes healthy and having the correct prescription. Your glasses prescription provides essential information about your vision requirements.   

 

Once your eye health is tested, your optometrist might recommend effective solutions. These can include wearing glasses or giving you an updated prescription for your glasses.

 

One common question associated with eye check-ups is “How to read eye prescription”. 

 

Your prescription comes with a combination of various letters and numbers. It defines the type and strength of the lenses you require.  

 

In this comprehensive guide, we will delve into the details of glasses prescriptions and explain the abbreviations and numbers. We will help you understand how to read glasses prescriptions and make an informed decision about your eyewear.

 

Let us read this guide!   

 

Why Do You Need Glasses Prescription?

An optician prescribes glasses to patients needing eyewear to enhance their eyesight. Glasses can help with nearsightedness (needing glasses for distant vision) and farsightedness (needing glasses for nearby objects).

 

The numbers on your prescription correspond to the lens strength needed for each eye. Sometimes, these numbers can be identical or vary based on the condition of the left and right eyes. A more significant number generally indicates a more potent prescription.

 

A prescription for glasses consists of a combination of various letters and numbers. The data outlines the category and power of glasses or lenses you may require. 

 

Eyeglasses and contact lenses mostly require different prescriptions. If you currently use glasses, you must undergo another eye test if you are considering using contact lenses.

 

A glasses prescription ensures you receive the best and most effective vision correction. It contributes to your overall eye health.

 

The following are the reasons you need a prescription for glasses.

 

Vision Correction:

A glasses prescription includes precise measurements customised for your eyes. These include sphere, cylinder, axis, and pupillary distance. These factors relate to vision issues like nearsightedness, farsightedness, and astigmatism. 

 

If you lack an accurate prescription, your glasses may not improve your vision correctly, leading to discomfort and imperfect vision. 

 

Customised to Individual Needs:

Every individual’s eyes are unique and need customised prescriptions. An eye care specialist evaluates your eye condition and visual requirements. 

 

The optician ensures your glasses meet your individual needs. Customisation helps attain optimal vision instead of generic remedies that might not cater to your condition.

 

Monitoring Eye Health:

Acquiring a prescription for glasses requires a thorough eye exam. An optometrist detects refractive errors and other possible eye health concerns during this examination.

 

It includes glaucoma, cataracts, and macular degeneration. Routine eye tests help in the early detection, management, and treatment of these issues.

 

Staying Updated with Changes in Vision:

Vision evolves with time owing to age, health issues, or lifestyle choices. Routine eye check-ups facilitate the timely adjustment of your glasses prescription. 

 

It ensures your eyesight stays clear and your eyewear continues to function. Regularly updating your prescription is essential for maintaining optimal visual performance.

 

What’s Included on Your Glasses’ Prescription Chart?

Depending on the location of your eye examination, glasses prescriptions may vary slightly. Many prescriptions include a chart featuring various terms, abbreviations, and numbers. 

 

Each indicates the state of your eye (left and right). The information is then combined to form the lens you require. Understanding what the chart suggests enhances your comprehension of your eye prescription.

 

Here, you have elements of the eye prescription explained –

 

Sphere (SPH)

SPH, or sphere, represents the lens power required for clear vision. It helps measure your level of nearsightedness or farsightedness. The number indicates the unit for measuring the correction (dioptres). The greater the distance from 0, the more substantial the correction required.

 

If the SPH value displays a minus sign (–), it indicates that you are nearsighted. Myopia refers to the ability to see nearby objects. More distant things will be hard to see and unclear. The greater your short-sightedness, the lower the number will be.

 

You are farsighted if the SPH number includes a plus sign (+). With hyperopia (long-sightedness), you will notice that distant objects are easier to see than nearby ones. With increasing long-sightedness, the plus number will be higher.

 

Cylinder (C or CYL) and Axis

Astigmatism is a common condition in which the eyeball is not perfectly spherical. When the eyeball is perfectly round, the light that enters it curves uniformly, creating a sharp image on the rear of the eye.

 

For individuals with astigmatism, the cornea is irregular, leading to a toric curvature.

 

Light rays originating from objects within the field of vision will not converge at a single point. This indicates that vision will become distorted and more blurred in specific directions compared to others.

 

CYL and Axis work together to correct your astigmatism.  

 

If you suffer from astigmatism, your prescription will indicate its intensity. Effectively reading eye prescriptions even helps to understand where the irregular curve is present in your eye –

 

This is outlined in three sections, helping you know how to read eye prescriptions:

 

Cylinder (CYL):

It indicates the level of lens strength required to rectify your astigmatism. It may be negative or positive. The greater the number, the more severe the astigmatism. If you lack astigmatism, or if its impact is minimal, you will not have a CYL number.

 

Axis:

It defines the location of the irregular curve that impacts your vision. It is a positive figure ranging from 0 to 180 degrees, functioning similarly to your eye diagram.

 

ADD, Prism and Pupillary Distance (PD)

“Add” refers to the lens strength required for improved reading clarity. It is found on prescriptions for reading glasses or for the lower section of varifocal lenses. 

 

These help correct natural age-related farsightedness (presbyopia). The range is the same for both eyes, from +0.75 to +3.00 D.

 

Prism refers to the prismatic power required for those with eye alignment issues. It is quantified in prism dioptres (p.d. or a triangle). 

 

It further clarifies how to place the prism on the glasses. It is done with BU = base up; BD = base down; BI = base in (toward the nose); BO = base out (toward the ear).  

 

Pupillary distance (PD) is a crucial aspect of reading glasses prescription. It indicates where the optical centre of your lenses ought to be positioned for optimal vision.

 

It calculates the space between your two pupils (the dark spots in your eyes). A pupillary distance is essential for aligning your prescription with the eyeglass frame.

 

What Do Eye Prescription Abbreviations Mean?

Understanding and reading spectacle prescription abbreviations is essential for deciphering your vision needs. 

 

Each abbreviation provides specific information about your eyesight, including nearsightedness, farsightedness, astigmatism, and the required corrective lenses. 

 

Wondering how you read glasses prescription? Understanding these abbreviations helps you decipher them.

 

 The abbreviations present in glasses prescription are –

 

• ADD refers to the additional lens strength required to enhance your reading experience. This number is given in prescriptions for reading glasses or the bottom section of bifocal or progressive lenses.

 

• Axis is a value ranging from 1 to 180. It shows where the astigmatism is located in your eye.

 

• BO, BI, BU, and BD represent base out, base in, base up, and base down. These abbreviations indicate to the eyeglass manufacturer where to place the prism on the glasses. This helps correct double vision.

 

• CYL refers to the cylinder, which indicates the level of astigmatism in your eye. The combination of the cylinder and axis helps in correcting astigmatism.

 

• DV stands for distance vision. This figure shows if you are nearsighted or farsighted.

 

• NV refers to near vision and signifies a person’s ability to read or see things at a close range. Opticians assess this measurement using a portable card with letters or numbers.

 

• NVO represents near vision exclusively. Doctors use it to facilitate reading for non-editable lens prescriptions (bifocal or progressive).

 

• OD is oculus dexter or your right eye.

 

• OU is oculus uterque, or both eyes.

 

• OS is oculus sinister, or your left eye.

 

• PD is known for pupillary distance. Monocular PD refers to the measurement from your pupil to the centre of your nose. Binocular PD refers to the measurement from one pupil to the other.

 

• A prism is used when you have double vision. It signifies the level of prismatic strength of your lenses. It helps to adjust differences in your eye alignment.

 

• SPH refers to the sphere, which denotes the lens power needed to improve your vision.

 

What Do Eye Prescription Numbers Mean?

Interpreting the numbers is crucial to understanding your glasses prescription and eye health. These numbers provide valuable insights into your vision requirements. 

 

It includes every detail, from how well you can see at different distances to specific conditions. Each prescription component serves a unique purpose, helping expert opticians determine the best corrective measures for your eyesight.  

 

Many of the abbreviations on your prescription are followed by numbers.

 

You are farsighted if the numbers have a plus sign (+) or no sign. You have myopia if these numbers display a negative sign (-).

 

Certain numbers in your prescription indicate to the eyeglass manufacturer the extent of correction required for your eyesight. The strength of eyeglasses is measured in diopters.

 

If your prescription indicates -1.00, your glasses require 1 diopter of power to address nearsightedness.

 

If your prescription indicates +2.50, your glasses require 2.5 diopters of power to fix farsightedness. The greater the number, the more adjustment your eyesight needs.

 

Wondering how to read eye prescriptions in the UK and find the strength of glasses you need for your eyes? The values indicating the strength are referred to as diopters. The diopters indicate the strength of the magnification.

 

If your reading glasses have a lower number, it means reduced magnification. More prominent figures indicate greater magnification strength. Reading glasses generally begin at +1.00 diopters and go up to +4.00.

 

What Is Near Sightedness & How Can Prescription Correct It?

Nearsightedness, often called myopia, is among the most common vision issues. Nearby objects are seen clearly in nearsightedness, whereas faraway ones appear blurred or unclear.

 

It becomes when the eye becomes excessively elongated from front to back, as measured by its axial length. The stretching of the eyeball leads to improper focusing of light rays on the retina, causing distant vision to be blurry. 

 

Although nearsightedness cannot be cured, different methods are available to slow down the advancement of myopia (nearsightedness). It can even happen if the cornea of your eye is too curved.

 

As a result of this greater distance, light rays fall in front of your retina. It is a light-sensitive layer that transmits signals to your brain directly on it. It results in your distant vision appearing blurred.

The lenses in your eyeglasses will correct the bend in the light and help you see distance. 

The lenses in your eyeglasses easily adjust the light’s angle and help you see faraway objects more clearly.

 

Considering a nearsighted prescription, the strength of the lenses is marked with a negative sign. The greater your nearsightedness, the larger the numbers will be.

 

For example, a lens prescription of -5.00 is more potent than -2.00. The power of the lenses may differ for each eye.

 

What Is Farsightedness & How Can Prescription Help It?

Farsightedness, also known as hyperopia, is a refractive condition of the eyes. It makes it difficult to see objects that are nearby compared to those that are farther away. 

 

It occurs because the gap from the cornea to the retina is too small. It can even happen due to an insufficient curvature of your eye’s cornea.

 

People with this condition frequently face challenges in reading, experience eye discomfort, and suffer from headaches during close-up activities.

 

Light converges behind your retina rather than directly on it if you have farsighted vision.

 

A plus sign indicates the lens strength in a farsighted prescription. The more farsighted you are, the larger the numbers will be. For example, a lens prescription of +4.50 is more potent than one of +2.00.

 

Correcting your vision with glasses for nearsightedness and farsightedness prevents –

• headaches
• eyestrain
• burning or stinging in your eyes

 

What Is Astigmatism & How Does Prescription Work For This?

Astigmatism is an uneven curve in the lens or cornea of the eye. This uneven curve bends the light entering the eye and influences how it strikes the retina.

 

Astigmatism makes nearby and distant objects appear blurry. It can also warp the visuals you observe.

 

It happens when the cornea, the transparent front part of the eye, has an irregular shape. This irregular shape alters how light enters the eye, leading to unclear or hazy vision. 

 

Astigmatism is a common condition; generally, most individuals possess some degree of it, but some have a greater extent than others.

 

Expert opticians measure astigmatism in diopters. A regular eye without astigmatism has 0 diopters.

If your astigmatism is 1.5 diopters or greater, you will need prescription glasses or contact lenses for clear vision. If you experience any degree of astigmatism, you might value the added clarity of prescription glasses.

 

Your prescription will indicate the severity of your astigmatism. It also helps understand the place where irregular curves appear in your eye.

 

Which Lenses Recommendations Should You Include In Your Prescription?

Selecting the appropriate lenses for your prescription is crucial for correcting your vision. Having a range of choices, you can significantly depend on understanding your requirements according to your prescription.

 

Let us take a look into the optician’s recommended lenses –

 

Blue Light Lenses –

Blue light lenses are an easy and efficient method of protecting your eyes. They can add remarkable worth to your eyewear collection. These distinctive glasses prevent blue light from reaching your eyes and enhance the clarity of your vision.

 

Bifocal Lenses –

Bifocal glasses are unique eyewear featuring two different prescriptions in a single lens. One lens helps correct far vision, whereas another provides clear sight for close objects. 

 

Bifocal glasses are designed to correct vision for close and far distances. They are beneficial for individuals requiring various vision corrections. 

 

Generally, older adults who experience difficulty seeing closer objects need bifocal lenses.

 

Anti-glare Lenses –

Anti-glare glasses shield your eyes and protect against bright lights. The anti-reflective coating regulates the quantity of reflective light reaching your eyes. 

 

The lenses are well-coated on the back, front, or sides to effectively manage light. Anti-glare glasses enhance vision, reduce eye strain and fatigue, and protect against UV rays.

 

Polarised Lenses –

Polarised lenses reduce glare and improve visual sharpness. They eliminate strong light reflections from water, roads, and glass surfaces. These lenses enhance contrast and offer more precise vision in bright settings. They amplify colour richness, making each detail stand out.

 

The main types of polarised lenses are –

• Standard Polarised Lenses
• Gradient Polarised Lenses
• Mirror-Coated Polarised Lenses
• Photochromatic Polarised Lenses

 

What about Contact Lens Prescriptions?

A contact lens prescription is a vital document from your optician. It details the specific requirements for the contact lenses you need. 

 

This prescription is derived from an extensive eye examination and considers your eyes’ distinct shape and features. 

 

Contact lenses sit directly on your eye’s surface and should match your eye’s curves.

 

A contact lens prescription contains measurements for:

 

• Base curve: It is a number ranging between 8 and 10, aligning to the shape of your eye.
• Diameter:  The distance from one side of the lens to the other. It ranges from 13 to 15 millimetres.

 

Your contact lens prescription specifies the lens brand, type, and expiry date. It must be renewed annually to reflect any changes in your eyesight and ensure a proper fit.

 

Using contact lenses without an appropriate prescription may result in eye irritation, infections, and other vision issues. Your eye specialist identifies the correct lens specifications, ensuring your eyes remain healthy.

 

Your contact lens prescription is customised to suit your vision requirements. Obsolete or inaccurate prescriptions may lead to blurred or distorted eyesight, which can even hinder your ability to carry out daily activities. 

 

Contact lenses that fit well and align with your prescription offer a pleasant wearing experience.

 

Get The Clarity You Need Reading Glasses Prescription With Royal Specs!

Choosing the proper reading glasses prescription enhances your reading experience and overall visual comfort. 

 

Understanding the abbreviations and figures on your eyeglass prescription helps you understand your eye health. These help your manufacturer customise the necessary glasses to address your issue.

 

Royal Specs brings you a wide range of stylish frames and high-quality lenses. Our expert opticians help you with your unique requirements and find the perfect pair of glasses.   

 

Wondering which one to choose, prescription vs. non-prescription glasses? Our experts will help you understand how you read glasses prescriptions in the UK. 

 

We are one of the leading frame retailers offering premium-quality glasses for all vision needs. Visit our website, submit your prescription, and select your frame from various options for optimally powered lenses. 

 

We bring you customisations along with a hassle-free 30-day eyeglasses return policy. 

 

Upgrade your vision and style with our premium eyewear!