You may understand that you have a problem with nearsightedness or farsightedness but can’t make sense of the eyeglass prescription you have. Many individuals with vision difficulties are unsure of what each prescription type means and how to understand it. From various numbers to abbreviations, eyeglass prescriptions can be complicated.
In this article, Blink Vision Care breaks down the common eyeglass prescription types, what they mean and their advantages to keep you informed and prepared for the next time you purchase eyeglasses.
Understanding OD and OS
This is the first step to understanding and decoding the eyeglass prescription. Both are abbreviations for Latin words known as:
- “OD” is an abbreviation for the oculus dexter, which stands for “right eye.”
- “OS” is an abbreviation for the oculus sinister, which stands for the “left eye.”
- “OU” may also be on an eyeglass prescription and is Latin for “both eyes.”
These abbreviations have been commonplaces on prescriptions for eyeglasses and contact lenses, however, some eye clinics use RE (right eye) and LE (left eye) instead.
Additional Eyeglass Prescription Abbreviations
Not all eyeglass prescriptions exclusively have “OD and OS.” Some other abbreviations and eyeglass prescription terms include:
- Sphere (SPH): This term refers to the total lens power, measured in diopters (D), which is used to refer to nearsightedness or farsightedness. This is the spherical amount of the prescription. If there is a (-) sign, you are nearsighted and if there’s a (+) sign, you’re farsighted.
- Cylinder (CYL): CYL is the total lens power for astigmatism. Cylinder means the lens power added to fix astigmatism is not spherical and one meridian has no curvature. It measures the degree of astigmatism in diopters. The larger the positive number, the more astigmatism you may have.
- Axis: Refers to a number from 1 to 180. Measured in degrees, axis refers to the location of astigmatism on the cornea. 90 represents the vertical meridian of the eye and 180 refers to the horizontal meridian.
- Add: This is often prescribed to individuals who require multifocal lenses to correct presbyopia. The prescription number you see will always be a “plus” even without the sign in front of the number. It refers to the magnifying power located at the bottom of a lens.
- Prism: Prismatic power rarely appears on prescriptions, but indicates the need to compensate eye alignment issues.
Some eyeglass prescriptions recommend specific lenses that are optional but recommended to improve your vision. These additional options may include:
- Photochromic lenses: These lenses are light-adaptive and adjust to light and dark when exposed to avoid irritating the eyes.
- Anti-reflective coating: AR coating, also known as anti-glare coating, reduces reflections to allow more light to pass through the lenses.
- Progressive lenses: These types of lenses are multifocal with no lines.
Blink Vision Care is your full-service eye clinic in Brampton for everything from eye exams to access to popular, high-quality eyeglasses and contact lens brands. We are your Brampton optometrists with over 25 years of experience improving our customers’ eye health. Visit our eye clinic in Brampton to check out our eyeglasses or contact us at https://blinkvisioncare.com/contact-us/!