How to Read Your Contact Lens Prescription

Glam Lenses make buying your contact lenses online even easier, as we don’t need to see your prescription before you order. This is because we trust that you have an up-to-date prescription and know which lenses you need. If you don’t have a copy to hand when ordering and can’t remember your specifics, you can even find the details of your prescription on the side/end of your last contact lens packaging.

What is my contact lens prescription?

A contact lens prescription contains all of your visual requirements and lets you know which type of lenses you need. To help make things that little bit simpler, we’ve written a guide on everything you need to know about your prescription when ordering contact lenses online.

It’s very important to note that a contact lens prescription is not the same as a glasses prescription. So, if you’re a glasses wearer who wants to try out contact lenses, you’ll need to go for a lens fitting to find out your requirements.

You should have been given your contact lens prescription from your optician after your last lens fitting. If not, then don’t hesitate to request your prescription, as it’s your legal right in the UK to own a copy.

What do my contact lens prescription figures mean?

contact lense prescription

Base curve (BC) – This figure determines the curve of the lens so that it can fit the curvature of your eye. This number is typically written in millimeters or sometimes given with the terms: flat, steep or median.

Diameter (DA) – Simply informing you of the width of the lens, this measurement is typically given in millimeters.

Power/Sphere (PWR/SPH) – Power or Sphere are used to indicate whether you are shortsighted or longsighted. A plus sign (+) is used for long-sightedness and a minus sign (-) is used for short-sightedness. The higher the number, the stronger the visual correction offered by the lens.

Prescription figures for astigmatism

Axis (AX) – Those with astigmatism have an unusual curve to their eye, which requires angular visual correction. The axis is a figure between 0 and 180, which determines how much of an angle of correction is offered.

Cylinder (CYL) – This is an extra figure, specifically for toric lenses, that lets you know the severity of the astigmatism and the extra visual requirements.

Prescription figures for presbyopia

Addition (ADD) - The Addition figure determines the level of correction needed for close distance visual clarity. This figure is between 0.50 and 3.00, or is sometimes referred to as low, medium or high.

Dominant (D) - multifocal contact lenses offer visual correction through a ‘dominant’ and ‘non-dominant eye’. The figures ‘D’ and ‘N’ are used to indicate which is which, respectively.