How to read your Prescription

What is a 'Prescription'?

Whenever you go to the opticians for an eye examination, there tends to be two main parts. The first being the health check and the second being the vision check.

After a complete examination, the Optometrist will provide you with a copy of your unique 'prescription' for glasses. The prescription, contains useful information such as the correct power of lenses needed to improve your eyesight.

In this article we will give you a simple breakdown of the key ingredients of a prescription and also elaborate on how to understand whats written.

SPH (Sphere)

This is the number of the power required to correct the vision.

Minus (-) = Short-Sighted

Plus (+) = Long-Sighted

CYL (Cylinder)

Another power needed to correct the vision.

The 'CYL' power is the number required to correct the 'uneven' part of the eye in Astigmatism.

Axis

Where we position the 'CYL' power, to correct the Astigmatism.

If you have no 'CYL' correction on your prescription, the AXIS will also be left blank.

Near Add

This is the 'ADD' power for near work (e.g. reading).

This power is important for somebody that needs reading glasses.

INT Add

This is the power to help correct the intermediate range. If you need glasses just for computer work or painting etc, this would be for that.

Prism

This is the power (Dioptres) needed to help the eyes muscles to focus. If you have slightly weaker eye muscles or need help with alignment this will be written on your prescription.

Base

This is the direction we need to put the prism to help with the eye alignment. Prism power and Base direction will normally come in pairs.

Sometimes Base direction can be written in a different format, e.g: BU, BD, BI, BO (Base Up, Base Down, Base In, Base Out)

What makes a prescription valid?

In order for a prescription to be valid and used to make glasses, there are specific key information that needs to be filled out:

*Date

*Patient Name/Address

*Lens Powers

*Optometrist Name

*Signature

*Recall (e.g. 24 months)

If there is information missing, you can always check with your opticians that have gave you the copy.