A prescription is a written order from an eye doctor that specifies the type of lenses you need and the power of those lenses. It is important to be able to read your prescription so that you can order the correct lenses when you purchase new eyeglasses or contact lenses online.
The Parts of a Prescription
A prescription typically has the following parts:
- Date: The date of your eye exam should be printed on the prescription.
- Sphere (SPH): This number indicates the amount of lens power needed to correct your vision. A minus sign (−) next to the number means nearsightedness (you see better up close and need distance correction). A plus sign (+) indicates you are farsighted (you see better far away and need your near vision corrected).
- Cylinder (CYL): This number indicates how much astigmatism you have, if any. Astigmatism is a condition where the cornea (the clear front part of the eye) is not perfectly round. This can cause blurred vision at all distances.
- Axis: This number indicates the direction of the astigmatism. It is measured in degrees from 1 to 180.
- Add: This number is only included on prescriptions for bifocal or progressive lenses. It indicates the amount of additional power needed for reading.
- P.D.: This number stands for "pupillary distance." It is the distance between your pupils. This measurement is important for ensuring that your eyeglasses fit properly.
How to Read Your Prescription for Online Eyewear Purchases
Once you know the parts of a prescription, you can start to read your own. Here are some tips:
- Look for the Sphere (SPH) number. This is the number that indicates the amount of lens power you need.
- Look for the Cylinder (CYL) number. This is the number that indicates how much astigmatism you have, if any.
- Look for the Axis number. This is the number that indicates the direction of the astigmatism.
- If your prescription includes an Add number, this is the amount of additional power needed for reading.
- Look for the P.D. number. This is the distance between your pupils.
Once you have read your prescription, you can use it to order new eyeglasses online. When you are ordering online, you will need to enter the information from your prescription into the form provided by the retailer. Be sure to double-check your entry to make sure it is correct.
Here are some additional tips for reading your prescription for online eyewear purchases:
- Make sure you are ordering the correct type of lenses for your needs. If you are not sure what type of lenses you need, ask your eye doctor.
- Be sure to check the return policy of the retailer before you order. Some retailers have a very strict return policy, so you want to make sure you are comfortable with the terms before you order.
- Order a few different frames to try on at home. This will help you find the frames that fit you best and that you like the most.
- You can always add the prescription later. If you are unsure of buying prescription lenses online, simply buy the frames you like and add in your prescription once the frames are delivered to you.
If you have more questions or would like some help, reach out to us through our contact page.