Understanding Your Prescription

Understanding Your Prescription in Olympia

Making Sense of Your Glasses Prescription

So you've completed your eye exam and you now have a copy of your prescription for glasses. Trying to understand it can be confusing. It can look like a hodgepodge of strange words, abbreviations, and numbers. While it isn't necessary to earn a degree in optometry to interpret it, it's a good idea to have a general understanding. 

Fortunately, with a little explanation it will begin to make sense. The following article will provide a simple breakdown of basic terms, abbreviations, and numbers. 

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Understanding Key Terms and Numbers

The following key terms and abbreviations are found on standard glasses prescriptions, starting with the columns from left to right:

  • RX/Eye- Both terms are used interchangeably.
    • OD: This refers to your oculus dexter, or right eye, as seen from the vantage of the optometrist when he assesses you. 
    •  OS: The oculus sinister refers to the left eye.
    • OU: Oculus uterque refers to both eyes.
  • Sphere (SPH): The term used to describe the overall lens power required to correct your vision. A plus ( + ) sign refers to distance corrections for farsightedness (hyperopia),  whereas the minus ( - ) sign is for nearsightedness (myopia). Lens power is measured by diopters. Ex. In the OS row,  + 4.00 means that the left eye needs 4 diopters of correction for farsightedness.
  • Cylinder (CYL): The next column addresses the cylinder number which indicates how much eye curvature you have. Not everyone has this condition, which is also known as astigmatism. The eye shape of people with astigmatism is sometimes likened to the general shape of a football, as opposed to the basketball-shaped eyes of those with no curvature.

Common Questions

They will not. Contact lenses have a different prescription because of how they are measured (fitted) to match the precise size and diameter of your eye.
Multifocals: These feature multiple focal points in the lens for different aspects of vision, such as distance vision, intermediate, and reading. Bifocals: These types of glasses have two prescriptions in the lenses. The top part is for regular vision, and the bottom is for reading. Bifocals are also multifocal. Progressive Lenses: These are also a type of multifocal glasses with the added advantage of them not having lines separating the sections. These glasses gradually shift their functions from the top of the lens to the bottom, allowing the wearer a more harmonious integration of the different features.
Understanding Your Prescription
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Reading Your Prescription

Understanding how to read a glasses prescription can seem daunting at first. As we have hopefully shown you in this article, once you understand the basic meaning of key terms and abbreviations, it makes a lot more sense. Always speak with your optometrist if you have any questions or concerns about your current prescription.
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Friday
8:30AM-3:00PM

Saturday-Sunday
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Location
400 Yauger Way SW. Bldg 1, Ste A Olympia, WA 98502
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(360) 459-1097
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