Prescription Help
Understanding your prescription

Your prescription is split into three sections, Sphere, Cylinder and Axis. You will most commonly see this written as, Sph, Cyl and Axis.

There are simple rules for each part of the prescription

Sphere – Is always a number in 0.25 jumps (i.e. 0.25, 0.50, 0.75, 1.00, 1.25). This can either be written in minus or plus (- or +).

IMPORTANT: You must select the correct symbol when ordering (minus or plus, – or +) as selecting the wrong sign will create the completely wrong prescription required to correct your vision.

Cyl – Is always a number in 0.25 jumps (i.e. 0.25, 0.50, 0.75, 1.00, 1.25). This can either be written in minus or plus.

IMPORTANT: You must select the correct symbol when ordering (minus or plus, – or +) as selecting the wrong sign will create the completely wrong prescription required to correct your vision.

Axis – Is a number between 0 and 180, it can also be written to point five (0.5) of a degree. This simply happens if the optometrist can’t decide wether you prefer for example 79 or 80 so they simply write your axis as 79.5. In this case lets get your glasses as accurate as possible so please provide us with the 79.5.

The in instances when a prescription doesn’t have a value for the Cyl section please leave the Axis blank (or some opticians write this as 0.00), the Axis is indicating what degree the Cyl figure sits at so if there is no Cyl there is no Axis required.

Infinity Symbol ∞ – this is another way of writing zero (no prescription) so simply select 0.00 into the corresponding section for either sphere or cyl.

Plano – this is another way of writing zero (no prescription) so simply select 0.00 into the corresponding section for either sphere or cyl.

You typically start to get the add part to a prescription when you hit 40+ and it is a measure of the amount of magnification you require to read.

The add is a plus (+) power which identifies how much extra addition (magnification) a glasses wearer requires (on top of their distance prescription) in order to read comfortably at close up distances, such as reading.

NOTE: Sometimes an optician will write your prescription for reading as a full prescription rather than simply supplying your reading add.

Example:

Distance

Right: -2.50 / -0.50 x 180

Left: -2.00 / -0.75 x 175

Near

Right: -1.00 / -0.50 x 180

Left: -0.50 / -0.75 x 175

Reading Add = +1.50

In this case to get your reading add take your distance Prescription Sphere  off your reading Shere. The difference between the two figures is your reading add used for Varifocals.

Pupil Distance

Let our Dispensing Optician Measure your Pupil Distance accurately

For the Pupil Distance options on the ordering pages select 'Let Extreme eyewear measure your PD' and we'll post you our specially designed glasses.

(Note: On some projects the PD option will state 'send ruler' this option will still get you the new PD Measuring Glasses)

All you have to do is take a simple photo of you wearing our glasses and emailing your photo to us.

Our Dispensing Optician will then accurately take your mono pupil distances. Our PD glasses allows our dispensing opticians to gain all the details they need to set up single vision and varifocal sunglasses / eyewear accurately.

Let us supply you with perfect vision.

This service is free for all prescription eyewear orders.