How to read your prescription

Sphere (SPH)
This shows the lens power needed to correct long or short sightedness. If it's + you are long sighted, if it's - you are short sighted.

Cylinder (CYL)
This shows the prescription for astigmatism. If this is blank you don't need a prescription for astigmatism.

Axis (AXI)
This shows the direction of the CYL. If you don't need a prescription for CYL you won't have an axis.

ADD (Addition)
ADD stands for the additional correction that you need for reading. It’s used for multifocal lenses and readers.

Pupillary distance (PD) How to Read PD? Measure here!
This is the distance between your eyes from the center of each pupil. We need this to ensure you have the best vision with your new glasses. If your PD measurement is a single value, split it in half to enter into the boxes.

Prism
Prism is used to correct diplopia (double vision). A prism bends light to align your vision so only a single image is seen.

Vertical Prism
Vertical prism correction is for vertical eye misalignments & prescribed upwards in one eye and downwards in the other.

Horizontal Prism
Horizontal prism correction is for lateral eye misalignments & prescribed in the same direction for both eyes.