How to Read My Prescription
How to Read
My Prescription
When you leave your eye doctor's office and look at your prescription, it may seem like an unrecognizable series of numbers and abbreviations. It makes ordering prescription glasses online challenging and overwhelming. Let's take a moment to decipher and understand what’s on your prescription. Let's get started.
Have NV/DV/SV on your prescription?
NV stands for near vision for reading use or computer use.
DV stands for distance vision for constant wear or daily use. Doctors usually use this to distinguish different usage.
SV means single vision. Doctors use this to tell you that you need single vision lens instead of bifocal or progressive lens.
How To Read Eyeglasses Prescriptions?
Then you need to know OD and OS. OD means 'right eye' and OS means 'left eye'.
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SPH |
SPH stands for sphere or spherical power. This indicates the amount of lens strength. There will be a plus sign for farsighted and negative sign for nearsighted - followed by a number. The larger the number, the stronger the prescription you needed to correct your vision. |
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CYL and AXIS |
If you have astigmatism, CYL and AXIS will be full in your prescription. Astigmatism is where the eye is not completely spherical but shaped more like a football. CYL or cylinder is the degree of how flat your eye is. The higher the number, the more astigmatism you have. The AXIS represents the orientation or angle of your astigmatism. From 1 to 180 degrees. |
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ADD |
ADD is an additional strength for your lens for reading or upclose work. If you need reading, intermediate, bifocal or multifocal, or progressive lenses, this should be listed in your prescription. |
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PD |
PD: This number indicates the distance from the center of one pupil to the center of the other, and is an important number for lens customization. If your prescription doesn't have your PD on it, don’t worry, we have a tutorial that teaches you how to measure your PD yourself. |
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Prism |
Prism: This is the amount of prismatic power, measured in prism diopters ("p.d." or a superscript triangle when written freehand), prescribed to compensate for eye alignment problems. |
Other questions
Q: What is a PD?
PD stands for Pupillary Distance, which is the measurement from the center of one pupil to the center of the other. Your PD is an important factor and tells you where you look through the lens of your glasses and should be as accurate as possible. For people with strong prescription, this is especially important. You can normally find your PD on your prescription. Generally speaking, the PD numbers for adults stays the same. The average PD range for adults is 57-72 mm and for kids is about 43-58 mm.
Q: I have dual PD, how can I enter it?
A dual PD would be provided with two numbers and would appear and is the measurement of each pupil center to the center of the bridge of the nose, in millimeters. Dual PD appears in the following format: "31.5/31.5". When placing the order, please click "Two PD numbers" to enter your dual PD.
Q: I have PLANO /PL under SPH on my prescription
If there is "Plano" or "PL" in the SPH section of an Rx, it means no nearsighted or farsighted correction is needed. Just leave it as a zero or Plano when entering the prescription on the order form on our website.
Q: I have SPHERE/SPH /S/DS under CYL on my prescription
If the optometrist wrote "DS" or "Sph" or "Spherical" in the Cylinder space, it indicates no correction and should be entered as 0 on the order form. This means that the eyeball is spherical and has no oblongedness, and consequently has no Cylinder or Axis values.
Q: I have BALANCE/BAL on my prescription
Balance indicates that the eye for which the designation is made, is not sighted, and that the same numbers should be entered in both eyes, in order to have the lenses matched in appearance and weight.
Q: I have PAL （progressive addition lens ）on my prescription.
PAL,the Progressive Adjusted Lens. Because of the limited reading area of a progressive lens design, the Add portion of a prescription is increased by a quarter of a diopter (typically) to compensate by increasing the size of the image. It does not change the size of that portion of the lens. If you have two ADD values in your prescription (ADD +2.00 and ADD +2.25 PAL), the ADD value +2.00 should be used for both eyes of bifocal while ADD value +2.25 should be used for both eyes of progressive.
Q: Can I use my contact lens prescription when ordering eyeglasses?
Unfortunately, contact lens and eyeglass prescriptions are different. The simple reason is because contact lenses sit directly on your eyes, while eyeglasses are held in front of your eyes. Though the prescriptions may appear similar, they will differ in strength and are not interchangeable. We cannot — and, for your safety, would not — use your contact lens prescription to make your glasses. And we would advise you to contact your eye doctor to get your eyeglasses prescription.
I have a prescription, how to read it for different uses
For progressive or bifocal glasses, the prescription can be read as:
For single vision distance use, the prescription can be read as:
To convert a multi-focal prescription with ADD values for single vision distance use, simply remove the ADD values. The correction for the astigmatism will not change, so the cylinder and axis will remain the same, regardless of the change in focal distance. Use the original distance PD listed in the prescription.
For single vision computer use, the prescription can be read as:
To convert a multi-focal prescription for single vision computer use, simply combine half of the Add number and the Spherical number (If the Add cannot be split evenly, such as ADD +2.25, both +1.25 and +1.00 can be used to convert the prescription). For example, if the Add were +2.25 and the OD-Sph was -0.50, the new OD-Sph for computer glasses would be +0.75; if the Sph were +0.25, the new Sph would be +1.50. Consequently, the Add will then become zero, the default. The correction for the astigmatism will not change, so the cylinder and axis will remain the same, regardless of the change in focal distance. Narrow the PD by 1-2 mm. If the PD of your basic prescription is 29.5/31.0, the PD for computer glasses would be 29.0/30.5 or 28.5/30.0
For single vision reading use, the prescription can be read as:
To convert a multi-focal prescription for single vision reading glasses, simply combine the Add number and the Spherical number. For example, if the Add were +2.25 and the OD-Sph was -0.50, the new OD-Sph for reading glasses would be +1.75; if the Sph were +0.25, the new Sph would be +2.50. Consequently, the Add will then become zero, the default. The correction for the astigmatism will not change, so the cylinder and axis will remain the same, regardless of the change in focal distance. Narrow the PD by 3mm. If the PD of your basic prescription is 29.5/31.0, the reading PD would be 28.0/29.5.
That's it about prescriptions.
For more information, check our help center. We hope this was informative and helpful!
FAQ
What do the 3 numbers in an eye prescription mean?
The three numbers in an eye prescription provide vital information about your required vision correction. The first value, Sphere (SPH), tells how much lens power is needed to fix farsightedness or nearsightedness. A positive number denotes farsightedness (hyperopia), while a negative number denotes nearsightedness (myopia). An integral part of the prescription, this measurement is represented in diopters (D).
The second number, Cylinder (CYL), relates to the lens power required to rectify astigmatism, a condition brought on by an unevenly shaped cornea. The cylinder measurement is likewise stated in diopters and can be positive or negative, the same as the sphere. Should there be no astigmatism, this prescription component could be blank or have "DS" (diopters sphere).
Measuring in degrees, the Axis value indicates the direction of the astigmatic correction. 0 to 180 is the range. It shows how cylindrical power should be used to fix the astigmatism. Finally, properly positioning lenses depends on knowing the Pupillary Distance (PD) -- the distance between your pupils.
Usually referred to as OD (right eye) and OS (left eye), a conventional eyeglass prescription consists of the first two numbers, generally representing the prescription of both your left and right eye. The pupillary distance, the third number, guarantees correct lens alignment for the best vision. Accurate design of spectacles that meet your particular vision requirements depends on an awareness of these three numbers. Having taken note of the above, GlassesShop is a highly advisable destination to consult on Sph prescription, Cylinder (CYL), and more optometry inquiries.
How do I understand my eye prescription?
Though it can seem intimidating, knowing your eye prescription is necessary to get the right glasses to meet your vision-correcting requirements. Your eye prescription consists of numbers and acronyms that specifically outline your needs. SPH is the first number; it shows the required lens power to either correct farsightedness (positive values) or nearsightedness (negative numbers). The initials OD and OS refer to your right and left eyes, respectively.
CYL is another crucial element, showing the lens power needed to fix astigmatism. Depending on the particular demands of your eyes, it may be beneficial or adverse. The Axis specifies the direction in degrees, indicating the astigmatic correction's orientation.
If your prescription calls ADD, this indicates the extra magnifying power required for close-up work, usually seen in bifocal or progressive lenses. If you need rectification for problems with eye alignment, Prism and Base numbers come into play. They show the required direction and degree of adjustment as well.
Finally, precisely placing lenses depends on knowing the PD, or pupillary distance, between pupils. Plano denotes zero or no corrective spherical power for people without prescription requirements. Knowing your eye lens prescription guarantees that the lenses you get meet your vision needs and help you interact successfully with eyecare specialists. Thus, you must take note of the information in any of your optometry prescriptions to get the required help and reduce unnecessary eye tests to discover the issue.
At what prescription do you need glasses to drive?
Regarding driving, safety should always come first; wearing corrective lenses can help guarantee good eyesight on the road. Usually predicated on visual acuity, the criteria for requiring glasses while driving include a peripheral vision test. Operating a typical passenger vehicle in most areas requires a minimum visual acuity of 20/40 (6/12) in at least one eye, with or without corrective lenses.
Still, there are several signs that you could need glasses for driving, even if your visual acuity satisfies the minimum criteria. Your prescription ranges between -0.50 to -1.00 diopters or worse; hence, you may start having trouble seeing far objects, particularly at night or in low-light circumstances. This can indicate that driving calls for spectacles. Similarly, suppose your prescription is around +1.00 diopters or worse. In that case, you may have trouble concentrating on things near you, but it is less likely to significantly affect your driving ability unless it causes notable eye strain.
Even modest astigmatism, shown by a CYL value of roughly ±0.50 or above, might cause blurriness or distortion of vision at all distances, possibly compromising your driving safety. Although an eye prescription with a sphere (SPH) value of ±0.75 diopters generally suggests minor vision correction needs, it is still advised to use glasses while driving to ensure the best clarity and address any possible difficulty in seeing clearly on the road. Giving clear vision acuity with suitable glasses priority will improve your driving safety and the safety of others.
What is considered a strong eye prescription?
The degree of vision correction required defines the power of an eye prescription. Regarding nearsightedness, a prescription is said to be strong when the Sphere (SPH) measurement exceeds -6.00. Likewise, a prescription is vital for farsightedness when the Sphere measurement exceeds +6.00. Astigmatism is said to be strong when the cylinder measurement comes over -2.00 degrees.
Those with powerful prescriptions should be aware that they could have to take some consideration of several elements. To save thickness and weight, lens materials should be high-index lenses or frames for high prescriptions. Furthermore, the lens type decision is critical. Many people with high myopia prefer contact lenses since they offer a more comfortable experience than ordinary glasses.
Accurate determination of the strength of your eye prescription depends on regular Sph eye exams. An expert optometrist can evaluate your vision acuity and precisely carry out the SPH measurement (Sphere measurement). Self-diagnosing or deciding your eye prescription without the required professional tools and knowledge is dangerous.
How do I find my eye prescription details?
There are several ways to determine your eye prescription; occasionally, you may find it alone. One approach is to check your current glasses packaging. Usually, the prescription information will be printed on these products so you may quickly find your prescription records. Still, another choice is accessing your prescription online. Conveniently access your prescription information using a glasses prescription chart on websites such as GlassesShop.com to identify the eye prescription from your most recent order.
If you cannot locate your prescription using these methods, contact your eye care provider. They can furnish the required information and have your prescription on file. Furthermore, if your previous eye exam was some time ago, consider booking one during your next one. Professionals who can precisely ascertain your eye prescription and offer you an updated prescription, if necessary, handle eye exams. Reading your eye prescription could mean knowing terminologies like the plus glasses prescription and consulting an eyesight prescription chart or lens prescription chart. Following these guidelines will help you quickly locate and grasp your eye prescription information, guaranteeing that you have the proper knowledge for your visual requirements.
