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About Prescriptions

How to get and understand your glasses prescription

You can ask for a copy of your prescription after an eye test in the uk, and the testing optician is obliged to give you a clear copy after your sight test to take away. It doesn't matter if you pay for or get a free NHS eye test, this still remains the same, and you must be given a copy under the Opticians act. The sight test must be accurate and fit for purpose and you are entitled to rely on its accuracy wherever you decide to purchase eyewear or lenses made up to it. Sometimes you may have to ask for it, although the law is clear on this and you shouldn't have to ask for it, it should be given freely if you decide to make a purchase with another spectacle supplier. Any disclaimer attached to the prescription about its accuracy is not legal and you are covered under your statutory consumer rights with regard to unfair contracts and disclaimers. "you have the right to rely upon the prescription wherever you buy your glasses or lenses from".


It's worth noting that a Pupil Distance measurement needed for the manufacture of glasses does not form part of an eye test and your optician will not usually provide this measurement unless you are purchasing glasses from their store. At Ilkeston Factory Specs we can legally take this measurement and have the latest equipment to measure your PD accurately when purchasing from us.




In the UK, there's several different prescription layouts and ways to write a spectacle prescription or RX.

The way one optician lays it out may be different from another optician. Despite the different ways to write and layout a prescription, all prescriptions contain the same information that you need to order glasses online.

The easiest way to minimise errors when ordering glasses is to simply upload a photograph of your prescription. This is our recommend method if you are at all unsure. However we understand that this may not always possible so we'll show you the most common ways a prescription can be written and how that would need to be put into our system when placing an order for glasses or lenses from us online.

About Prescription Values:

A prescription consists of up to three values for each eye and sometimes a fourth (but not always) Reading Add+

+ or - SPH (Sphere)

+ or - CYL (Cylinder)

AXIS (from 1 to 180 degree's)

There will be either a plus or a minus sign in front of the SPH and CYL values, and it's vital that you select the correct symbol when you enter your prescription. If you use a + instead of a - or vice versa, you won’t be able to see through your glasses at all.

If your prescription has a value in the ‘Prism’ box please do not place an order with us online.


Question - How do I know what to enter on your system to order the glasses i need ?

If you are at all unsure then please upload your prescription as it's written or contact us.

1: For Single Vision Distance glasses:

Everyday use at long distance, tv and driving etc where you just use one pair of glasses (generally people under 40 years old).

Take the values from the top row (highlighted Blue in the image below) right and left eyes and enter them in the relevant indicated boxes on our cart page manual entry form. Make sure you enter the right values in the right eye boxes and left eye values in the correct left hand boxes on our site. Ensure you correctly enter + or - symbols. This will enable us to make you single vision long distance glasses. 

2: For Single Vision Reading glasses:

Reading glasses are a little more complicated because reading values can be written in two different ways: as a whole value, or as an ‘add’.


If your prescription has an ‘ADD’ written in the Near row this tells us the extra power we need to add to make your lenses up and suitable for reading and near vision. We will use your distance prescription(Sph value) with your ‘ADD’ added on top to make your glasses up for reading. 

However, if you don't have an ‘ADD’ indicated but instead you have all of the values written out in the Near row underneath the maths have been done in full for us already. This is your full near prescription for reading. For single vision reading glasses you should enter your full reading prescription entering the values from the bottom line only or the top line distance prescription and the add.

What if I have an 'add' and values in the reading row ?

If your prescription has both a ‘Near’ section written in full and an ‘Add’ on it somewhere it would be less common. If in doubt send us an uploaded picture of your prescription and we'll decipher it for you.

How to order the lenses you want on our system:


1 - To order long distance lenses - Use/enter the Distance values (top line only in distance boxes)  to order long distance glasses for the tv, driving etc.


2 method A- To order near vision lenses - Either use/enter the Distance values in full (top line) and then the reading add if there is one written

2 method B- use/enter the Near vision values in full (bottom line in the near box) if your optician has written your prescription out 'in full' this way –


but please do not mix both methods. Take care not to add the 'reading add' to the bottom line near vision values.This can only ever be added to the Distance vision values (top line)

This equation has already been done by the optician and the bottom line near values are all you need for near vision reading glasses.. If you put (add) a Reading +add on top of your near vision reading prescription (bottom line), you’ll end up with glasses far too strong for you to be able to see through or use because you are doubling up on the reading prescription powers needed.

About varifocals?

You'll need to Upload your prescription to order Varifocal glasses online with us.

For varifocals, we need your distance prescription and your add, so that we can make your lenses with both distance and reading parts to them. Please upload your prescription to save a costly error

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