Understanding Your Glasses Prescription

Understanding Your Glasses Prescription. Your Spectacle Prescription Explained.

An explanation for the numbers and symbols on your glasses prescription.

After an eye examination your optometrist will provide you with a copy of your spectacle prescription.

Typically it wil be in the format

RE (for right eye spectacle correction)

LE (for left eye spectacle corrrection)

Sph Cyl  Axis  Prism  Add


Sph (Sphere/DS) +/- number ,which goes up in steps of 0.25
+ Sphere lenses are provided to correct long sightedness when you need a spectacle correction to improve your near vision

- Sphere lenses are prescribed to correct myopia/short sightedness when your eyes need help to see clearer in the distance

Cyl (Cylinder/DC) +/- number, also goes up in steps of 0.25. Cylinder lenses are prescribed to correct astigmatism (an eye condition where the front of your eye is shaped more like a rugby ball rather than a soccer ball)

Axis - in degrees from 0-180 for the orientation of the cylinder lens correction

Add - if your require a separate reading prescription, for extra focussing power at close up distance this will always be a + number, which also increases in steps of 0.25

This add may be written as a separate figure eg +1.00, +2.00 etc or it can be written in a form on your glasses prescription record where it is combined with your existing distance prescription.
This near add is most commonly prescribed for pxs over the age of 40 or in cases where a patient needs very sharp focus when looking at fine details.

Prism Amount -this is prescibed if you have a problem with your two eyes focussing together, and will have a numerical amount with IN/OUT UP/DOWN indicating the prism base direction needed to correct your binocular vision problem.

Please note your contact lens prescription is not the same as your spectacle/glasses prescription and cannot be used to order glasses.
At a later stage we will update our website with information explaining the differences between glasses and contact lenses prescriptions.


Here are some sample presciptions:

To correct simple short sight

RE :  -2.00 Sph 

LE: -2.50  Sph

with astigmatism correction

RE -2.00 DS/-1.00 Cyl Axis 90

LE -2.00 DS/-1.50 Cyl Axis 80


The incorrect selection of a “+/plus” or a “-/minus” symbol when ordering spectacles online can result in a wrong pair of prescription glasses.
That is why when you are ordering glasses from The Little Spectacle Shop we request customers after placing their order to email or Whats App a copy of their spectacle prescription.


Hopefully the information provided will help you to uderstand your own glasses prescription, but if you need any explanation about yours please get in touch and we will be happy to assist.