How To Read Your Glasses Prescription
Everybody is Wearing Glasses
Glasses have become something of a fad at this point, with over 60% of adult Americans wearing them now. They’re definitely in style but you also need them. Having clear vision is far more than just a luxury. Many Americans love and need their prescription glasses to enjoy seeing their visual activities in everyday life.
What’s in a Prescription
A written prescription is designated for both of your eyes. You will have two separate rows labeled:
- OD – Right eye
- OS – Left eye
As well as columns for:
- SPH – The Sphere power is nearsightedness if minus power and farsightedness if plus power, and located in the first column.
- CYL – The Cylinder power is required to correct astigmatism. The higher the number the more astigmatism you have. If there is no cylinder recorded, you do not have astigmatism in the prescription.
- AXIS – The Axis is the angle or orientation of the astigmatism power from 1 to 180 degrees.
- ADD – The Add power is the reading power and can be corrected as a progressive (no line separating distance from near), bifocal (line separating the distance Rx on top from the reading Rx on the bottom), or single vision, near vision only, lenses.
In general, the farther your number in the Sphere and Cylinder columns are from zero, the more powerful your prescription. A positive value means you are farsighted and a negative value means you are nearsighted. The cylinder and axis sections are for people who have astigmatism.
As for contacts, your prescription will show two extra values:
- BC – Base curve
- DIA – Diameter
Both numbers are measurements your eye doctor uses to fit the lens to your eye as a medical device. This encourages both a comfortable fit and proper oxygen flow to the cornea to prevent infection. Base Curve and Diameters cannot be arbitrarily assigned, and must be prescribed by your eye doctor.
At Accent Eye Care & Sports Vision Therapy, our first priority is delivering quality eye care you can trust. We also specialize in Vision Therapy to help those struggling in school with visually related learning issues, those making a recovery from a stroke or head injury, or just looking for a competitive edge in sports. Educating Phoenix and its surrounding communities about proper eye care is an important mission to us. We aim to expand your knowledge of your eyes and how to properly care for them. Your eye health is our number one concern. If you have any further questions about your prescription, or if you are currently looking for new eyewear, please feel free to call our opticians today at 602-547-3255.