How to read your eyeglass prescription

May 03, 2019

Guide to prescriptions

prescription glasses

Our goal is to help you understand what the numbers mean when you put your prescription in manually. At we allow you to put in your eyeglass prescription manually or upload your actual prescription which takes the hassle out of not understanding what the prescription numbers mean. Most online retailers will ask you to put in your prescriptions manually. Here is an explanation of the process if you do it this way.

prescription eyeglass

PD Measurement

What do the numbers mean when you put in your medicine manually? We will enable you to place in your eyeglass prescription manually or upload your actual order at an online eye prescription, which solves the issue of not understanding what the prescription numbers mean.

The initial step in understanding your online eye prescription is recognizing what "OD" and OS" mean. These are abbreviations for the right eye and left eye demonstrated by Latin words oculus dexter and oculus sinister. Your online eye prescription may have a column marked "OU" additionally.

It is the abbreviation for the Latin expression oculus uterque, which denotes "the two eyes." Previously it was tough to understand any eye specialist prescription, but now online eye prescription has made quick yet straightforward.

On your eyeglass prescription, the data for your right eye (OD) precedes the data for your left eye (OS). Eye specialists write eyeglass prescriptions along these lines since when they face you, they see your right eye to their left side (first) and your left eye to their right hand (second).

Your eyeglass prescription consists of different terms and abbreviations, too, but you don't need to worry about the presence of online eye prescription. These include sphere (SPH), which shows the measure of lens power and calculations in terms of diopters (D).

If the number has a minus sign (–), you are nearsighted; & in case of the plus sign (+), you are considered farsighted. The expression "sphere" implies that the correction for nearsighted or farsightedness is spherical or equivalent in all meridians of the eye. Cylinder (CYL) demonstrates the amount of lens power for astigmatism; if this column is blank, then it means you have little or only no astigmatism for correction.

The term cylinder at online eye prescription implies that this lens power added to address astigmatism isn't spherical. Yet, rather than this, it is shaped so that no added curvature is present in one meridian as well as no added power is present in the meridian perpendicular to this. Meridian contains the maximum power and shape of the lens to address astigmatism.

The number in the cylinder segment might be preceded before with a minus sign (for rectification of nearsighted astigmatism) or a plus sign (for farsighted astigmatism). Now you don't need to visit the doctor again and again to understand the prescription; all you need is to visit online eye prescription, and here we are for your assistance.

Axis portrays the lens meridian that contains no cylinder power to address astigmatism. It is with a number from 1 to 180. Figure 90 compares to the vertical meridian of the eye, and the number 180 relates to the horizontal meridian. Previously eye prescription was not less than understanding a tough math question, but now you don't need to pressure your brain; all you need is to visit online eye prescription, and we will do all this for your better assistance.

Add is the additional magnifying power applied to the base of multifocal lenses to correct presbyopia. The number at online eye prescription is showing up in this segment of the eyeglass prescription is always a plus power regardless of whether it isn't gone before by a plus sign.

Generally, it ranges from +0.75 to +3.00 D, and both eyes will have the same power. This term is elaborately available at online eye prescription. Prism is the measure of prismatic power, calculated in terms of the prism diopters or a superscript triangle when composed freehand, recommended to make up for alignment issues eyes.

Online eye prescription enables you to understand all these terms and choose the most appropriate number for eyeglasses. Prism is in a tiny percentage of eye prescriptions. Fractional English or metric units are used to express the amount of prism when present (0.5 or ½, for example), and the direction of the prism is demonstrated by taking note of the relative situation of its base.

All your problems and queries can remove at online eye prescriptions. We should go through an example to clear any doubts about online eye prescription. Here is an example eyeglass prescription:

OD - 1.00 SPH +1.00 add 0.75 P.D. BD
OS - 1.00 - 0.750 x 180 +1.00 add 0.75 P.D. BU

Eye specialist has recommended a 1.00 D sphere for rectification of nearsightedness in the right eye (OD). No axis or cylinder power has no astigmatism correction required for this eye. The left eye (OS) is being recommended - 1.00 D circle for nearsightedness and - 0.750 D cylinder for the correction of astigmatism.

The cyl power has 180 meridians of the axis, which means the horizontal meridian has no additional power for astigmatism while the vertical meridian has - 0.750 D. The both eyes are being prescribed for +1.00 D as add power for the correction of presbyopia.

Prismatic correction of 0.75 prism diopter is also involved in this eyesight prescription for each eye. In the left eye, the prism is base up (BU) while base down (BD) is for the right eye. See how simple and quick it is; enter your eye prescription at online eye prescription, and you will get the best guidance regarding your eyesight numbers.

Eye Prescription Online

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"Here at, we want to make your experience simple and easy. By understanding your prescription, it will make input of your eye data a breeze."

- Yishai Grossman -

Now you are ready to understand your prescription. You can discuss these with your optometrist as well. These are the most important things to understand when purchasing your glasses online. Now that you finished learning what everything means, what are you waiting for? Begin saving on your next pair of glasses and start shopping here at right away.

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