Wondering what all those numbers on your glasses prescription stand for?

Here is an example of what your glasses prescription might look like and what those numbers and symbols mean. Your vision specialist evaluates all of the components shown to determine your best possible corrected vision. 


OD - Right Eye

OS - Left Eye

Sphere - 

This indicates the amount of lens power prescribed to correct nearsightedness (- value) or farsightedness (+ value). Sphere is the main correction in your corrective lenses.

CYL (Cylinder) - 

This, along with the AXIS, compensates for astigmatism (an irregularity in the shape of the eye). If there is no value present, then you either do not have an astigmatism or it is negligible and your doctor does not feel a correction is necessary. 


The angle at which your cylinder (CYL) correction needs to be placed for optical clarity.

ADD (Add Power):

Magnifying power that is added to the distance prescription in the lower half of multifocal lenses. This restores near vision for adults with presbyopia. These values normally range from +0.75 to +3.00. 


This reading is to compensate for eye alignment problems. The directional terms refer to the location of the thickest edge of the prism and this is called the base.