Understand your prescription& what the numbers mean Understand your prescription & what the numbers mean

When you're handed your prescription by an Optometrist after an eye exam, it can feel a little daunting. There might be quite a few numbers that don't make any sense to you without an explanation and jargon that you just don't make sense of. If your optometrist doesn't explain any of the numbers to you, it can leave you even further in the dark and a little clueless about your upcoming purchase.

So what do all of the letters and numbers mean? We've put together a handy guide for you, to enable you to make sense of everything from start to finish.

In the first heading of the table, you will see the letters 'Sph'. This is short for 'Spherical', which is a round lens that needs to be included as part of the lens you need. Beneath Sph will be either a '-' or '+' sign, and an additional number. The '-' represents a shortsighted person and the '+' a longsighted person. The higher the number is, the stronger the prescription.

The second heading will have the letters Cyl, which stands for cylindrical. If this box comes with numbers underneath, this means you have an astigmatism. It is nothing to worry about; it simply means that your eye is shaped a little more like a rugby ball, rather than a football.

If you do have an astigmatism as above, the third box will also have a number in it. It will have a heading called 'axis', and the number will be between 1 and 180. This is the number that represents the axis where a lens needs to be positioned in the spectacle frame. If you don't have an astigmatism, you won't have a number in this box.

Sometimes there is a fourth box called 'prism', which will have a number and either the words IN, OUT, UP or DOWN. These means that a lens called a prism need to be included in your lens because of a muscle imbalance or double vision in the eye. The prism helps to correct these issues.

Below the boxes as above is a box labeled "Add". If this box has been filled in then you may require glasses for reading or the computer. It can be written in two ways. Either for example +2.00/+1.00X180 or as just +2.00 Add.

PD - Pupillary Distance which is the distance between the centre of one eye and the other eye. This number helps the glazer (who makes the glasses) ensure that the middle of the lenses in the frames, match up to the middle of your eyes. This isn't always noted on your prescription, and you can ask for it. If the PD is missing, we can advise you on how you can measure this yourself.

If there is a VA number on your prescription, we don't require this.

Your prescription date

Your prescription by law must be valid for up to 2 years; if you leave it some time to get your glasses and your prescription is older than 2 years, you will need to have another eye exam at your opticians.

How to send your prescription to us?

If you don't feel confident writing your prescription numbers in to the boxes provided on the website, you can either contact us by phone or scan and email the prescription to us and we will contact you. Please note: If there is a prism on your prescription we advise you contact us as there may in some instances be an additional charge.

How to get your prescription?

Following the eye examination undertaken by the Optometrist a copy of your spectacle prescription will be provided. If for any reason the prescription is not presented be sure to request your copy.

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