

How to Read Your Eye Prescription
An eyeglasses prescription is provided by your optometrist after a
routine eye test and has information about the type of glasses you need
and the strength of prescription for your lenses.
Read on to
find out more about how to read a glasses prescription and when you
should update yours.
What is an eyeglasses prescription?
If you need glasses, a prescription will specify the exact strength
which is needed to correct your vision. This occurs after your pre
testing, where you get your
eye pressure tested, and is given to you by an optometrist.
Because your
prescription is more than just the correction for near or
farsightedness, you shouldn’t share your glasses with another person,
even if you think you have the same prescription.
How do I find out my glasses prescription?
An eye prescription for glasses is provided by an optometrist once they
have completed your
eye test. But you will only receive a prescription if your vision needs
correcting.
This glasses prescription is then handed over to
the optical dispenser so that they can help you pick the most suitable
glasses for your needs and prescription.
How to read an eye prescription chart?
A spectacles prescription chart can look very confusing for someone who
doesn’t work in the eye care field, as it is filled with abbreviations
and different numbers and symbols.
Below is an explanation
of the different numbers and abbreviations you would find on an
eyeglasses prescription chart.
SPH (Sphere)
Indicates the amount in numerals of long-sightedness (denoted with a “+” symbol), or short-sightedness (denoted with a “-” symbol) you have. It will determine the power of the lens you need for clear and comfortable vision.
PD (Pupillary Distance)
The measurement in millimetres of the distance between the eyes. It is used to ensure that your lenses are positioned properly to give you clear vision. Your Pupillary Distance value is required when ordering a new pair of glasses.
CYL (Cylinder)
Represents the amount of astigmatism you have (denoted with a “-” symbol). We correct this by using a CYL lens that is equal but opposite to your astigmatism.
AXIS
Specifies the angle, between 0-180 degrees, which corrects astigmatism. You cannot have AXIS or CYL without the other as they work in tandem for astigmatism correction.
ADD
Shows the amount of magnification required for close vision (denoted with a “+” symbol). This could include if you need reading glasses or your reading prescription for bifocals and/or multifocals.
Int ADD (Intermediate ADD)
Representing the amount of magnification required for computer vision, which is typically about 70cm away. This prescription will be in between your near and distance vision.
PRISM
If you have double vision or trouble with focusing, prism can
sometimes be used to improve these issues.
The base may
be included on your prescription if you have prism, as it informs
the lab of the direction to put the prism on your lenses and if it
needs to be applied to one eye or both.
Get a new prescription
Book an eye test with one of our friendly optometrists.
What is a normal glasses prescription for eyes?
20/20 vision is used as a way of quantifying normal vision. It is a term that represents your visual acuity and is based on letter charts you see at the optometrist. If you have 20/20 vision, you would most likely not need a prescription, unless you have other issues such as astigmatism or a vision condition.
Can wearing lower prescription glasses damage your eyes?
Wearing glasses with a different prescription to your own will not damage your eyes or vision, but is it not recommended as it can cause eye discomfort.
How long is an eyeglasses prescription valid?
The prescription you receive from your optometrist for glasses will include an expiration date. A spectacles prescription is usually valid for 1-2 years depending on contributing factors such as age and existing eye conditions.

Can I use an expired glasses prescription?
No. You should not use an expired glasses prescription as your vision
may have deteriorated over time, leaving you with an inaccurate
prescription requiring a new one. Wearing glasses with an outdated
prescription can cause headaches, eye strain and blurry vision.
At Oscar Wylee, we do not accept expired prescriptions but
you can easily get a new prescription for your glasses by booking an eye
test with one of our friendly optometrists.
How often does eyeglasses prescription change?
How often your glasses prescription changes can vary from person to
person. For some, it may be every year, for others, it may be longer.
Some factors that contribute to the rate at which your
glasses prescription changes include:
- Presbyopia - An age-related eye condition that affects near vision.
- Astigmatism - Common condition that causes blurry vision, eye strain and headaches that can change over time.
- Cataracts - Age-related changes in the lens of the eye, leading to a decline in clear vision.
Or, if you notice any significant or sudden change in your eyesight, seek care from an eye care professional immediately.
When should I update my glasses prescription?
We recommend that you get a regular eye test every two years and annually if you are over the age of 65. An optometrist will test your vision to see if you need an updated glasses prescription.
Looking for your next pair of glasses?
Contact or visit your nearest store for a full quote.
All major health funds accepted in-store.


Book an eye test
Book an eye test with one of our trusted optometrists.
Oscar Wylee offers bulk billed eye tests, so there are
no out-of-pocket expenses for eligible Medicare cardholders.