Eyeglasses Prescription Guide

September 18, 2019


It is the job of the optometrist or ophthalmologist to provide you with your eyeglasses prescription once you have consummated the ocular perceiver exam. By having your prescription you get all the pertinent information about the condition of your ocular perceivers as well as being able to injuctively authorize glasses online if you so desire.

However, your prescription may be plenary of terms, numbers, and abbreviations that you may not be all that habituated with. After all, what precisely does OS, OD, CYL or SPH authentically mean anyway? Here you will learn what all of the terms mean so that you can be best apprised about your ocular perception as well as understanding all the information obligatory to injuctively authorize eyeglasses online.


The Terms Used in Eyeglasses Prescription:

There are a number of terms that are utilized on your prescription and they commence with OD, OS, and OU. To understand these terms which are derived from Latin will avail you ken what your prescription genuinely betokens.
OD: Ocular Dexter – Left Ocular perceiver
OS: Oculus Sinister – Right Ocular perceiver
OU: Oculus Uterque – Both Ocular perceivers

Plus, while it may seem remotely eccentric that medicos put the information from your right ocular perceiver ahead of your left ocular perceiver, that is because when they face you they visually perceive your right ocular perceiver first and then examine the left.

Depending on your medico or clinic, you may find that in lieu of utilizing Latin phrases, they instead use LE and RE for Left Ocular perceiver and Right Ocular perceiver respectively.
SPH (Sphere): This promulgated the amount of lens power needed to redress the vision. The number associated with SPH will either have a “-“ or a “+” sign which designates if the ocular perceiver is nearsighted or farsighted respectively. Sometimes farsighted is simply denoted by the number alone.

CYL (Cylinder): This is the denotement of the lens power needed to rectify astigmatism. If you do not optically discern a number in this column, then you have no astigmatism or it is so remote that no rectification is needed.

Like the SPH you will visually perceive a minus or plus sign to betoken either nearsighted or farsighted respectively.
Axis: This is utilized to describe the lens meridian if it has no CYL power to rectify the astigmatism. The number 90 is the vertical meridian while 180 is the horizontal meridian.

Integrate: The integrated magnifying power that is utilized on the bottom part of a multifocal lens. This is utilized to redress presbyopia. The number is always a positive one and will customarily range from .75 to 3.00 D and will be identically tantamount for both ocular perceivers.
Prism: The amount of prismatic power as quantified in prism diopters (PD). This is utilized for the alignment of the ocular perceiver itself. Very few eyeglasses prescription will contain this information.


A Typical Eyeglass Prescription:

A standard eyeglasses prescription will contain unique information for each person, but it will appear in generally the same order with the associated terms.

OD: -1.00 SPH     +2.00 ADD     0.4 p.d. BD
OS: -2.00 -0.50 x 180     +2 ADD     0.5 p.d. BU

Here, the prescription is for a -1.00 D sphere that corrects the nearsightedness of the right eye. Not that there is no astigmatism for that eye and the doctor has added SPH to show the right eye is only being prescribed spherical power.

The left eye is -2.00 D for nearsightedness and added -0.50 D cylinder which will correct the astigmatism. The 180 is the axis which means that the CYL power is no applied to the horizontal plane while the vertical gets the added correction.

Since both eyes are being corrected for nearsightedness, the prescription contains a 0.5 prism diopter (p.d.). The BD indicates the prism is down for the right eye while BU is prism up for the left eye.



In 1980, the Federal Trade Commission enacted the Prescription Release Rule that requires ocular perceiver medicos to give patients a facsimile of their prescriptions for eyeglasses at the terminus of the examination. The information additionally includes the refraction as well.

The law sanctions you to peregrinate somewhere else and purchase glasses so that way you are not locked into a single source for getting incipient glasses.
Your medico will provide you the prescription whether you ask for it or not to forfend themselves in terms of the law.

They cannot charge you for relinquishing the prescription nor can they relinquish the information to anyone else. Additionally, they are still liable if their prescription is erroneous if you purchase the eyeglasses at another location.

The penalties are fairly rigorous when ocular perceiver medicos transgress the law, so it would be highly unwonted for you not to get the prescription included at the cessation of your ocular perceiver exam.

You can take this information to another place to purchase your glasses or even buy eyeglasses online if you so desire. Many online sites will have the form yare to fill out so that you can insert the information and get the right lenses. In this manner, you can buy glasses online for a price that is identically tantamount or sometimes even less sumptuous than purchasing them from a local store.

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