When you get a prescription lenses prescribed to you from your optometrist you may wonder what some of the terms and numbers mean on the glasses RX you get.
We have customers who order prescription lens blue light glasses from us and we use the eyeglass prescription info provided by our customers in order to create their custom blue light glasses order.
What Does Sphere (SPH) for Glasses Mean?
Sphere is abbreviated as SPH and means the correction of your farsightedness (long-sighted) or nearsightedness (short-sighted) is equal across all meridians of your eye i.e. spherical.
SPH is measured in diopters (D) which indicates the amount of lens power needed to help correct your vision.
If the SPH number you see has a minus sign (-) in front of it that means it is correcting nearsightedness.
If the SPH number you see has no minus sign or has a positive sign (+) it means it is correcting farsightedness.
What Does Cylinder (CYL) for Glasses Mean?
Cylinder is abbreviated as CYL and means the amount of lens power needed to correct an astigmatism.
If you see no number in this column on a glasses Rx then it means you have no astigmatism or one that is so small that it was deemed not needing correcting.
If the CYL number you see has a minus sign (-) in front of it that means it is correcting nearsightedness astigmatism.
If the CYL number you see has a plus sign (+) in front of it that means it is correcting farsightedness astigmatism.
What Does Axis for Glasses Mean?
Axis has no abbreviation and means the angle of the astigmatism and the value is the lens meridian that has no cylinder power for correcting astigmatism. The Axis value is denoted between 1 - 180 degrees.
There will be an Axis value if you have been a confirmed astigmatism that needs correcting.
