The contact lens prescription contains all the critical information provided by the ophthalmologist that you would need when placing an order for contact lenses. A prescription is necessary to ensure that you get the required lenses as per your eye health that is not only safe but also provides clear vision.
However, reading a contact lens prescription is not easy; as you know, a doctor’s handwriting is not easy to understand. But, what’s even more difficult and challenging is decoding the abbreviations and codes that make no sense for normal people.
You need to know what the terms mean and what the abbreviations stand for in your contact lens prescription, especially when you are ordering the lenses online. If we talk about contactlenses4us.com, you can easily order varied contact lenses without any prescription!
In order to determine the right fit of the lenses, number, and expiry date, among others, you need a prescription.
So, in this post, we will be answering all the related questions regarding contact lens prescription.
OD and OS:
At the side or top of any contact lens prescription, you will find the letters OD and OS (capital letters). Well, they simply denote Left and Right. OD denotes the ‘Right Eye’ and OS denote the ‘Left Eye.’ These are the Latin terms for the same.
- OD: Oculus Dexter
- OS: Oculus Sinister
On the other hand, in some cases, you will see the letters OU on your contact lens prescription, which is short for ‘Each Eye.’
- OU: Oculus Uterque
If OU is written on your prescription, it means the same measurement applies to both eyes.
PWR is short for ‘refractive power.’ In some cases, it is denoted as SPH, which means ‘Sphere.’ PWR is the amount of correction that is needed to bring your vision to 20/20. It is measured in diopters. If your PWR is preceded by a minus (-) sign, it means you are nearsighted (myopia), and if your PWR is preceded by a plus (+) sign, it means you are farsighted (hyperopia). It is normal to have a different prescription in each eye.
BC refers to the Base Curve or Back Curvature of the contact lens. BC is measured in millimeters and usually lies between 8 and 10. Based on BC, the fit of your contact lens is determined.
DIA refers to Diameter of the contact lens. The diameter is the distance across the contact lens surface, which is measured in millimeters as well. DIA is usually around 13-15 millimeters. It is imperative to have the measurement right because if it isn’t, it can cause irritation.
CYL refers to the Cylindrical Value of the contact lenses. CYL is the amount of power required to correct your astigmatism. The cylindrical value usually lies between -4 and +4.
Axis is the term used to express the positioning of CYL on the lenses. The Axis number is displayed in degrees – between 0° and 180°.
ADD denotes the addition of the magnifying power to the lenses in portions to help with clear vision.
Lastly, your contact lens prescription may also display color, brand, and other details. For example, if you have preferred to enhance your eye color cosmetically, it will be mentioned in your prescription.