So, you’ve just had an eye exam and your optometrist has given you prescription glasses for Zeiss, Hoya, Essilor or Nikon lenses. Your optometrist probably mentioned that you are MYOPIA or Hyperopia, or perhaps that you have astigmatism.
But what do all those numbers on your prescription glasses mean? And what about all those abbreviated terms, such as OD, OS, SPH and CYL?
What is OD and OS ?
The first step to understanding your prescription glasses is knowing what “OD” and OS” mean. They are abbreviations for terms for Right eye and Left eye.
Your prescription glasses also may have a column labeled “OU.” This is the abbreviation for both eyes.
Other Terms on Your Prescription Glasses
Sphere (SPH). This indicates the amount of lens power, measured in diopters (D), prescribed to correct Myopia or Hyperopia. If the number appearing under this heading has a minus sign (–), you are myopic; if the number has a plus sign (+) or is not preceded by a plus sign or a minus sign, you are Hyperopic.
Cylinder (CYL). This indicates the amount of lens power for astigmatism. If nothing appears in this column, either you have no astigmatism, or your astigmatism is so slight that it is not really necessary to correct it with your eyeglass lenses.
Axis. This describes the lens meridian that contains no cylinder power to correct astigmatism. The axis is defined with a number from 1 to 180.
Add. This is the added magnifying power applied to the bottom part of multifocal lenses to correct presbyopia (reading problems). The number appearing in this section of the prescription is always a “plus” power, even if it is not preceded by a plus sign. Generally it will range from +0.75 to +3.00 D and will be the same power for both eyes.
At Malaya Optical, you would be checked by Qualified Optometrist who has experience in management of presbyopia (reading problems), pediatric (children myopia), corneal refraction (contact lenses prescription) and many more.