How Do I Read My Eye Prescription

Understanding your prescription

What do the messages, numbers and symbols on my prescription mean?

Apart from your name and date of nascency, you volition notice that there are quite a few letters, numbers and symbols on your prescription. This is what they all mean:

'+' or '-'

'+' – Shows if you are long sighted (longsightedness)

'-' – Shows if you lot are curt sighted (shortsightedness)

SPH or Spherical number

This shows how strong the correction needs to be. A '-' symbol in a higher place the number indicates shortsightedness whereas a '+' symbol indicates longsightedness. Other symbols that can exist found in this department are the infinity symbol (which looks like a sideways eight) or the word Plano (or Pl), which are the equivalent of 'zilch' and are used when no sight correction is required. Another common term that can exist found on prescriptions is V/A (or visual acuity) which measures the standard of vision when corrected.

CYL or Cylinder number

This shows how much astigmatism you lot have and the number tin can exist negative or positive. Astigmatism is when the front part of your centre is shaped more like a rugby ball than a regular circle. If you don't take an astigmatism, there will exist no figures written in the cylinder and centrality boxes.

AXIS

This shows the position of the cylinder. It will be betwixt 1 and 180.

PD or Pupillary distance

This is the distance betwixt your eyes measured betwixt your pupil centre points. Commonly, the optician will not add this to your prescription, and so you should ask for it as it'due south of import for those with high-strength prescriptions to take lenses that are centred more accurately. To inquire for your PD, you lot can tell your optician that you will exist purchasing an particular they do not stock, such as prescription goggles online.

Add together

This will betoken if yous need a prescription for reading and is practical to bifocal and varifocal lenses to correct presbyopia. Y'all may also have an Inter Add for computers or other tasks like reading music on a stand.

PRISM

This shows if you have a muscle imbalance in your middle. It's less common to run across this box filled in as it'southward adequately rare. The prism is usually written in fractions (for instance 1 ½).

BASE

This shows the management of the prism in your lens, for example IN, OUT, UP or Downwardly. This is fairly uncommon and so the boxes are usually empty.

You can read more than virtually different types of prescriptions here.

Common layouts of prescriptions

Beneath are examples of prescriptions. The first set are standard - look through these to become a feel. It'due south mostly handwritten prescriptions that cause problems but typed ones are generally easier to sympathize. For each prescription, we as well included how it would appear when calculation it to our website.

At the stop of the page are examples of unusual cases you may encounter, with instructions for what to do. Skip straight to the more than unusual items.

This is a standard NHS prescription:

It would exist written as follows:

NHS Scotland

• Here the signs take been written ABOVE the numbers - they are withal just standard +/- signs.
• It can be hard to tell where 1 number ends and the side by side one begins. It helps to know that sphere and cylinder will e'er exist in the format (x)x.yy, with x existence a number from 0 to x and yy being either 00, 25, 50 or 75. Axis is always a number between 1 and 180.

Information technology would be written as follows (you tin click "My prescription is more complex than this…" to expand the card):

Boots

It would be written as follows:

Specsavers

It would be written as follows:

Vision Limited

Information technology would be written as follows:

More unusual figures

If y'all need a prism for one or both optics, it will await similar to this:

We can provide lenses with a prism correction, but you'll need to contact u.s.a. to discuss this.

Sometimes figures like this announced on your prescription. These are not needed to make your lenses.

Some prescriptions accept this figure, which looks like a sideways 8. This ways 'infinity'. And you should select 'infinity' from the list.

This prescription too has some figures scrawled underneath - these are additions for both intermediate and near distances. Even though it's a single figure, it applies to both optics.

To enter this, you'll need to use the "My prescription is more complex than this…" link to show the more than advanced prescription area.

Sometimes opticians write 'DS' in the CYL column. This simply means there is no astigmatism, and yous tin can enter either nothing (exit the field blank) or select the phrase DS in the drib downwardly.

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Source: https://www.glassesdirect.co.uk/help/understanding-your-prescription/