How to obtain a precise eyeglass prescription

How to obtain a precise eyeglass prescription?

An eyeglass prescription is provided by a doctor – such as an ophthalmologist or optometrist. It is important to get a prescription from an eye doctor who will specify the value of all parameters he or she deems necessary to construct or dispense lenses appropriate for you. In this article, we will tell you “how you can obtain the precise eyeglass prescription.” We recommend you to read this article thoroughly so that you get the most out of it.

How to Read Eye Glass Prescription

You don’t need a medical degree or training to read eyeglass prescriptions. After completing the eye exam, your doctor will write an eyeglass prescription, which usually includes several abbreviations and numbers. For instance, you will see O.D (right eye), O.S (left eye), O.U (both eyes), CYL for the identification of astigmatism, AXIS, DV, NV, and ADD.  
How to Read Eye Glass Prescription
For each eye, there are specific numbers after O.D, O.S, and/or O.U. These are known as spherical correction or SPH – and they are usually measured in diopters. Doctors or eye lab personnel use this number to identify the durability of the lenses to correct your vision.

In addition, you are nearsighted if the number has a (-) minus sign next to it. Similarly, you are farsighted if you see there is a (+) sign. Likewise, regardless of the minus or plus sign, if the number is higher, it means you need a stronger prescription.

What does OD vs. OS mean?

When you get eyeglasses prescription, you will see some numbers that are listed under headings such as “OS” and “OD.” OS stands for oculus sinister, which means left eye. Similarly, OD stands for oculus dextrous, which means the right eye.

SPH: It stands for spherical power – describing the degree of farsightedness or shortsightedness. When you have a positive SPH or SPH+, it means you are farsighted. Similarly, if you see a negative or minus SPH on the prescription, it means you are nearsighted.

CYL: it stands for “cylinder” – indicating the power of lens for the correction of your astigmatism. If you don’t see any numerical value in the prescription, it means that your doctor has not found astigmatism.

Axis: If your doctor has considered CYL, there is a need for indicating position, which is done through axis value. Actually, it is a number from 1 to 180 measured in degrees. It is used to determine astigmatism on cornea.

Add: It is used in multifocal lenses. The purpose is the indication of extra magnifying power for the lens’ bottom part.

Prism: It is used by doctors when there is a necessity for eye alignment compensation.

What is Your PD (Pupillary Distance)

PD stands for Pupillary Distance, which is used for measuring the distance between your pupils’ centers. Doctors use this measurement to determine how and where you look through the eyeglasses lens and work accordingly to make it as accurate as possible. On average, the pupillary distance or PD of an adult is between 54-74 mm and for children, the value is between 43-58 mm.
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