What Does My Prescription Mean?

It's a question we get asked regularly, so I thought I would give you a quick summary of what we need to see to process your prescription.

First, make sure you have an up-to-date prescription (not more than two years old).  Then, make sure that the prescription includes the following measurements:

• Sphere (or SPH) – this gives the strength of the lens (plus for long-sightedness, minus for short-sightedness)

• Pupiliary distance (or PD) – this is the horizontal distance between your pupils measured in millimetres (as a guide, the average is between 60mm and 66mm) - we'll use an average if we can't get this info

• Cylinder (or CYL) – this is your astigmatism correction.  Not everyone has astigmatism (when the eye is slightly rugby-shaped) so don't worry if you don't have a measurement for this

• Axis – this corrects an astigmatism and tends to be an angle measurement like 150 or 90

• Addition (or ADD) - this is a number we add to your distance prescription to give the reading measurement for your bifocals.  For bifocals it's really important you get your optician to tell us what position the reading and distance segments should be - we can use an average again, but it may lead to some blurring in the final glasses,

• And by the way, OD and OS - it means your right eye and left eye (OD and OS are latin abbreviations for right eye and left eye)

Comments

[Sahr]

Hi,
The prescriptions I have worn most of my life say that I have an axis of 180 for my left eyes. I am currently living out of my home country and do not have access to the same kind of healthcare here. When I got my eyes examined here, the doctor wrote an axis of 20 for my left eye. All the others numbers correlated in a predictable manner except this one. This was way off from what I've been seeing before. What does that mean? And what is the correct one for me to stick with? I need to know urgently because I am having somebody send me a pair of eyeglasses with an updated prescription from back home.
Thanks very much.

[Evelyn]

For years have I have been wearing prescription glasses,
My prescription is Left +050 and Right +075 then add 125 what does that mean.

[jacky]

I also need prescription before I will buy my eyeglass. I am experiencing watery eye especially when i am in front of my computer unit.. Hope not to have bad results after visiting my doctor for this. I want to know the level that i can say that my eye problem would still be ok.