Your Browser is OutdatedHow to Read Your Sunglasses Prescription — Page 1
EyewearPlanet.com offers Rx prescription sunglasses , eyeglasses , prescription safety glasses, prescription goggles , and even prescription motorcycle sun glasses, prescription sports glasses , and prescription ski goggles that you can buy directly from our online store! RX Adaptors and Prescription Inserts are available for some eyewear models.
Please note that all prescription sunglasses are custom made according to the prescription information you provide when you place your order. If your eyeglasses prescription was issued more than a year ago, we at EyewearPlanet.com highly recommend you to visit your optometrist to get a new prescription.
Below we provide additional information on how to properly read your Rx prescription. We are here to help , please e-mail us or call us toll-free (800) 504-5897 if you have any questions!
Different Types of Prescription Lenses
Considering a particular eyesight disorder , a different rx lens can be prescribed. As a rule opticians distinguish 4 types of prescription lenses: single vision , bifocal , trifocal and progressive .
Single vision lenses have only one viewing area throughout the lens. This corrected area can be for far distance, near distance or reading.
Bifocal lenses have two distinct viewing areas within the same lens; the distance area and the near area. The distance area in bifocals is designed like a single vision lens , while the near area contains the distance prescription and the additional amount of ADD power needed to see at a reading distance. If you would like to learn more about lined bifocals please visit Bifocal Lenses in Prescription Sunglasses page.
Trifocal lens is an extension of the bi-focals , which provide vision correction only for distance and close up near viewing, leaving the intermediate area between distance and reading uncorrected. Tri-focals provide another segment on the lens above the reading viewing area to correct the intermediate viewing area between far and near.
Progressive lenses correct vision for two or three different distances without the visible segment lines seen in bifocal or trifocal lenses. Instead they have a graduated section in which the power of the lens progresses smoothly from one prescription to the other, allowing the wearer to see clearly at all distances. Transition Zone is the area of progressive sunglasses lenses where the distance vision curve gradually changes into the near-vision curve. For additional information on Prescription glasses with Progressive Lenses please visit our Progressive Lens page.
Eyeglass Prescription
Eye examination prescription as a rule contains a number of different abbreviations and terms. Below you can find definitions of the most commonly used vision terms.
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SPH = SPHERE - The amount of long or short sightedness. This value specifies the optical power of a lens in diopters. It always has a plus (+) or a minus (-) sign in front or above it. The lens power for the distance correction will be minus while the correction for near distance and reading will be plus power. There will always be a value for sphere, even if it is just zero (written as 0.00, Plano or P). If the vision in one eye is very poor, the word 'balance' or 'bal' may be written.
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AXIS - This will only appear if there is a value for cylinder, as it relates to the cylindrical lens and denotes a reference point that indicates the direction of the power of the cylindrical lens. It will be a number between 1 and 180. It may or may not be written with a degree 'o' symbol after the number. In some prescriptions, the axis value is indicated on a semi- circular scale. This should be read to the nearest 5 degrees.
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PRISM is a box on the rx prescription form that is not normally filled in. Occasionally, when the two eyes are not properly aligned and looking directly at the same thing, PRISM can be ground into the lenses in order to re-align them. This can occur with strabismus (ie - an eye turn) or in situations where the eyes are properly aligned but are under a tremendous amount of strain in order to keep them aligned. The value under the 'prism' heading denotes the strength of the prism.
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BASE - rotation of the prism that is simply specified as 'base in' (where 'in' means towards the nose)or 'base out' or 'base up' or 'base down'. Only these four positions exist, however, orientations between these four positions can be specified by using combinations of horizontal and vertical prisms in the same lens.
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PD = PUPILLARY DISTANCE - This measurement is used to accurately center the lenses in the frame that you have selected. PD is the distance from the center of the pupil (black circle) in one eye to the center of the pupil in the other eye. It is called Binocular PD . In cases where the pupils are not equidistant from the nose, a monocular PD is required. Monocular Pupil Distance is measured from the centerline of the nose to each pupil. In such a case you will have different values for the right eye (OD PD) and the left eye (OS PD). Another reason for more than one Pupil Distance is the need to correct both distance and near vision. In this case the prescription will state Near PD and Dist PD . The Near PD measurement is shorter than the Distance PD by 2 to 5 mm because the eyes turn in at near distance. PD measurement is a must for all RX orders for it insures that your prescription lenses in your glasses are alligned properly in front of the eyes. If you are unable have your Pupil Distance measured by optician , you can try our printable millimeter ruler (please note that you will still need to contact your optician to get accurate Near and Dist PD measurements required only for bifocal and progressive rx lenses) |
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1. Place the millimeter ruler on the bridge of your nose ( download printable ruler here ).
2. Have a friend face you about arms length away.
3. Have your friend measure the distance between the centers of your pupils (or do it yourself by looking in the mirror).
Typical adult's Pupillary Distance measurements (PDs) are 58 to 70
Typical children's Pupillary Distance measurements (PDs) are 41 to 58
You can also get this information from your eye doctor or from a licensed optician or just call the last place where you ordered prescription eyeglasses .
Reading Portion of the Eyewear Prescription
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ADD = ADD POWER (Sometimes referred to as SEG POWER as well)- It is additional plus power in the lower portion of a multifocal lens ( progressive , bifocal , or trifocal ) that is required for near vision. |
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SEG HT = SEGMENT HEIGHT -is the distance from the lowest portion of the eyewear to the top horizontal line of the Segment.You will need to know the Segment Height for the frame you chose. You might need to take the frame to the optician for him to measure the Seg. Height for this particular kind of frame to fit properly. If you are thinking of ordering sunglasses with progressive or bifocal lenses please take a look at our trial program . |
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PLEASE NOTE, IF YOUR DOCTOR SKIPPED ANY OF THE MEASUREMENTS MENTIONED ABOVE (WITH THE EXCEPTION OF PD AND SEG HT), PLEASE LEAVE IT BLANK WHEN SUBMITTING YOUR ORDER.
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Prescription Abbreviations
| O.D. or OD - (Latin oculus dexter) right eye | |
| O.S. or OS - (Latin oculus sinister ) left eye | |
| O.U. or OU - (Latin oculus uterque ) each eye | |
| D.V. or DV - distance vision | |
| N.V. or NV - near vision | |
| PL or plo - plano (a placeholder for the number zero) | |
| D.S. or DS - diopters sphere (it means that you have sphere power only) | |
| X - axis (x 90 stands for axis 090) |
Note on Prescription sunglasses measurements:
Your prescription may be written out on a blank Rx pad , instead of a pre-made Rx sheet for eyeglasses only. The top values are the prescription for the right eye and the bottom values are the prescription for the left eye.
If there are no numbers for CYL, AXIS or ADD in your prescription , leave these fields blank when ordering. When only one number appears for each eye, it is for the sphere power only.
For some prescriptions there will be no astigmatism correction for one or both eyes. Your doctor may just write the sphere power alone, or may use abbreviations like sph ("sphere") or D.S. ("diopters sphere").
If there is only one ADD power on your prescription for bifocals, this means that the same ADD power is used for both eyes. If there is no ADD power given, leave this section blank when ordering.
Please do not hesitate to contact us if you have any problems understanding or entering your prescription.
Please note that you may need some time to adjust to your new prescription sunglasses . If you cannot adjust to your new prescription sun glasses, you might need a slight fitting adjustment by your local optician.
Please note that you may not be able to see well with your new prescription sunglasses if you enter incorrect prescription information such as inaccurate pupillary distance measurement when placing your order! Please note that we cannot be responsible for mistakes in prescription information provided by you or your optometrist or ophthalmologist. We guarantee that your rx sunglass will be made exactly to the specification that you provide when placing your order on-line in our store! Any changes to your prescription order made after it has been submitted to the lab will result in charges of 50% of the price for the original order. All cancelled rx jobs after the order was already placed will be charged 50% of the price for the original order as well. If your eye glasses prescription was issued more than a year ago, we at EyewearPlanet.com highly recommend you to visit your local optometrist to get a new prescription. If your prescription has changed recently, your eyes might need to adjust to the new prescription lenses.